/*
Copyright 2024 Google LLC
Use of this source code is governed by an MIT-style
license that can be found in the LICENSE file or at
https://opensource.org/licenses/MIT.
*/
// SPDX-License-Identifier: MIT
#pragma once
#include <iostream>
#include <string>
#include <vector>
#include <regex>
#include <memory>
#include <stdexcept>
#include <sstream>
#include <unordered_set>
#include <json.hpp>
using json = nlohmann::ordered_json;
namespace minja {
class Context;
struct Options {
bool trim_blocks; // removes the first newline after a block
bool lstrip_blocks; // removes leading whitespace on the line of the block
bool keep_trailing_newline; // don't remove last newline
};
struct ArgumentsValue;
inline std::string normalize_newlines(const std::string & s) {
#ifdef _WIN32
static const std::regex nl_regex("\r\n");
return std::regex_replace(s, nl_regex, "\n");
#else
return s;
#endif
}
/* Values that behave roughly like in Python. */
class Value : public std::enable_shared_from_this<Value> {
public:
using CallableType = std::function<Value(const std::shared_ptr<Context> &, ArgumentsValue &)>;
using FilterType = std::function<Value(const std::shared_ptr<Context> &, ArgumentsValue &)>;
private:
using ObjectType = nlohmann::ordered_map<json, Value>; // Only contains primitive keys
using ArrayType = std::vector<Value>;
std::shared_ptr<ArrayType> array_;
std::shared_ptr<ObjectType> object_;
std::shared_ptr<CallableType> callable_;
json primitive_;
Value(const std::shared_ptr<ArrayType> & array) : array_(array) {}
Value(const std::shared_ptr<ObjectType> & object) : object_(object) {}
Value(const std::shared_ptr<CallableType> & callable) : object_(std::make_shared<ObjectType>()), callable_(callable) {}
/* Python-style string repr */
static void dump_string(const json & primitive, std::ostringstream & out, char string_quote = '\'') {
if (!primitive.is_string()) throw std::runtime_error("Value is not a string: " + primitive.dump());
auto s = primitive.dump();
if (string_quote == '"' || s.find('\'') != std::string::npos) {
out << s;
return;
}
// Reuse json dump, just changing string quotes
out << string_quote;
for (size_t i = 1, n = s.size() - 1; i < n; ++i) {
if (s[i] == '\\' && s[i + 1] == '"') {
out << '"';
i++;
} else if (s[i] == string_quote) {
out << '\\' << string_quote;
} else {
out << s[i];
}
}
out << string_quote;
}
void dump(std::ostringstream & out, int indent = -1, int level = 0, bool to_json = false) const {
auto print_indent = [&](int level) {
if (indent > 0) {
out << "\n";
for (int i = 0, n = level * indent; i < n; ++i) out << ' ';
}
};
auto print_sub_sep = [&]() {
out << ',';
if (indent < 0) out << ' ';
else print_indent(level + 1);
};
auto string_quote = to_json ? '"' : '\'';
if (is_null()) out << "null";
else if (array_) {
out << "[";
print_indent(level + 1);
for (size_t i = 0; i < array_->size(); ++i) {
if (i) print_sub_sep();
(*array_)[i].dump(out, indent, level + 1, to_json);
}
print_indent(level);
out << "]";
} else if (object_) {
out << "{";
print_indent(level + 1);
for (auto begin = object_->begin(), it = begin; it != object_->end(); ++it) {
if (it != begin) print_sub_sep();
if (it->first.is_string()) {
dump_string(it->first, out, string_quote);
} else {
out << string_quote << it->first.dump() << string_quote;
}
out << ": ";
it->second.dump(out, indent, level + 1, to_json);
}
print_indent(level);
out << "}";
} else if (callable_) {
throw std::runtime_error("Cannot dump callable to JSON");
} else if (is_boolean() && !to_json) {
out << (this->to_bool() ? "True" : "False");
} else if (is_string() && !to_json) {
dump_string(primitive_, out, string_quote);
} else {
out << primitive_.dump();
}
}
public:
Value() {}
Value(const bool& v) : primitive_(v) {}
Value(const int64_t & v) : primitive_(v) {}
Value(const double& v) : primitive_(v) {}
Value(const std::nullptr_t &) {}
Value(const std::string & v) : primitive_(v) {}
Value(const char * v) : primitive_(std::string(v)) {}
Value(const json & v) {
if (v.is_object()) {
auto object = std::make_shared<ObjectType>();
for (auto it = v.begin(); it != v.end(); ++it) {
(*object)[it.key()] = it.value();
}
object_ = std::move(object);
} else if (v.is_array()) {
auto array = std::make_shared<ArrayType>();
for (const auto& item : v) {
array->push_back(Value(item));
}
array_ = array;
} else {
primitive_ = v;
}
}
std::vector<Value> keys() {
if (!object_) throw std::runtime_error("Value is not an object: " + dump());
std::vector<Value> res;
for (const auto& item : *object_) {
res.push_back(item.first);
}
return res;
}
size_t size() const {
if (is_object()) return object_->size();
if (is_array()) return array_->size();
if (is_string()) return primitive_.get<std::string>().length();
throw std::runtime_error("Value is not an array or object: " + dump());
}
static Value array(const std::vector<Value> values = {}) {
auto array = std::make_shared<ArrayType>();
for (const auto& item : values) {
array->push_back(item);
}
return Value(array);
}
static Value object(const std::shared_ptr<ObjectType> object = std::make_shared<ObjectType>()) {
return Value(object);
}
static Value callable(const CallableType & callable) {
return Value(std::make_shared<CallableType>(callable));
}
void insert(size_t index, const Value& v) {
if (!array_)
throw std::runtime_error("Value is not an array: " + dump());
array_->insert(array_->begin() + index, v);
}
void push_back(const Value& v) {
if (!array_)
throw std::runtime_error("Value is not an array: " + dump());
array_->push_back(v);
}
Value pop(const Value& index) {
if (is_array()) {
if (array_->empty())
throw std::runtime_error("pop from empty list");
if (index.is_null()) {
auto ret = array_->back();
array_->pop_back();
return ret;
} else if (!index.is_number_integer()) {
throw std::runtime_error("pop index must be an integer: " + index.dump());
} else {
auto i = index.get<int>();
if (i < 0 || i >= static_cast<int>(array_->size()))
throw std::runtime_error("pop index out of range: " + index.dump());
auto it = array_->begin() + (i < 0 ? array_->size() + i : i);
auto ret = *it;
array_->erase(it);
return ret;
}
} else if (is_object()) {
if (!index.is_hashable())
throw std::runtime_error("Unashable type: " + index.dump());
auto it = object_->find(index.primitive_);
if (it == object_->end())
throw std::runtime_error("Key not found: " + index.dump());
auto ret = it->second;
object_->erase(it);
return ret;
} else {
throw std::runtime_error("Value is not an array or object: " + dump());
}
}
Value get(const Value& key) {
if (array_) {
if (!key.is_number_integer()) {
return Value();
}
auto index = key.get<int>();
return array_->at(index < 0 ? array_->size() + index : index);
} else if (object_) {
if (!key.is_hashable()) throw std::runtime_error("Unashable type: " + dump());
auto it = object_->find(key.primitive_);
if (it == object_->end()) return Value();
return it->second;
}
return Value();
}
void set(const Value& key, const Value& value) {
if (!object_) throw std::runtime_error("Value is not an object: " + dump());
if (!key.is_hashable()) throw std::runtime_error("Unashable type: " + dump());
(*object_)[key.primitive_] = value;
}
Value call(const std::shared_ptr<Context> & context, ArgumentsValue & args) const {
if (!callable_) throw std::runtime_error("Value is not callable: " + dump());
return (*callable_)(context, args);
}
bool is_object() const { return !!object_; }
bool is_array() const { return !!array_; }
bool is_callable() const { return !!callable_; }
bool is_null() const { return !object_ && !array_ && primitive_.is_null() && !callable_; }
bool is_boolean() const { return primitive_.is_boolean(); }
bool is_number_integer() const { return primitive_.is_number_integer(); }
bool is_number_float() const { return primitive_.is_number_float(); }
bool is_number() const { return primitive_.is_number(); }
bool is_string() const { return primitive_.is_string(); }
bool is_iterable() const { return is_array() || is_object() || is_string(); }
bool is_primitive() const { return !array_ && !object_ && !callable_; }
bool is_hashable() const { return is_primitive(); }
bool empty() const {
if (is_null())
throw std::runtime_error("Undefined value or reference");
if (is_string()) return primitive_.empty();
if (is_array()) return array_->empty();
if (is_object()) return object_->empty();
return false;
}
void for_each(const std::function<void(Value &)> & callback) const {
if (is_null())
throw std::runtime_error("Undefined value or reference");
if (array_) {
for (auto& item : *array_) {
callback(item);
}
} else if (object_) {
for (auto & item : *object_) {
Value key(item.first);
callback(key);
}
} else if (is_string()) {
for (char c : primitive_.get<std::string>()) {
auto val = Value(std::string(1, c));
callback(val);
}
} else {
throw std::runtime_error("Value is not iterable: " + dump());
}
}
bool to_bool() const {
if (is_null()) return false;
if (is_boolean()) return get<bool>();
if (is_number()) return get<double>() != 0;
if (is_string()) return !get<std::string>().empty();
if (is_array()) return !empty();
return true;
}
int64_t to_int() const {
if (is_null()) return 0;
if (is_boolean()) return get<bool>() ? 1 : 0;
if (is_number()) return static_cast<int64_t>(get<double>());
if (is_string()) {
try {
return std::stol(get<std::string>());
} catch (const std::exception &) {
return 0;
}
}
return 0;
}
bool operator<(const Value & other) const {
if (is_null())
throw std::runtime_error("Undefined value or reference");
if (is_number() && other.is_number()) return get<double>() < other.get<double>();
if (is_string() && other.is_string()) return get<std::string>() < other.get<std::string>();
throw std::runtime_error("Cannot compare values: " + dump() + " < " + other.dump());
}
bool operator>=(const Value & other) const { return !(*this < other); }
bool operator>(const Value & other) const {
if (is_null())
throw std::runtime_error("Undefined value or reference");
if (is_number() && other.is_number()) return get<double>() > other.get<double>();
if (is_string() && other.is_string()) return get<std::string>() > other.get<std::string>();
throw std::runtime_error("Cannot compare values: " + dump() + " > " + other.dump());
}
bool operator<=(const Value & other) const { return !(*this > other); }
bool operator==(const Value & other) const {
if (callable_ || other.callable_) {
if (callable_.get() != other.callable_.get()) return false;
}
if (array_) {
if (!other.array_) return false;
if (array_->size() != other.array_->size()) return false;
for (size_t i = 0; i < array_->size(); ++i) {
if (!(*array_)[i].to_bool() || !(*other.array_)[i].to_bool() || (*array_)[i] != (*other.array_)[i]) return false;
}
return true;
} else if (object_) {
if (!other.object_) return false;
if (object_->size() != other.object_->size()) return false;
for (const auto& item : *object_) {
if (!item.second.to_bool() || !other.object_->count(item.first) || item.second != other.object_->at(item.first)) return false;
}
return true;
} else {
return primitive_ == other.primitive_;
}
}
bool operator!=(const Value & other) const { return !(*this == other); }
bool contains(const char * key) const { return contains(std::string(key)); }
bool contains(const std::string & key) const {
if (array_) {
return false;
} else if (object_) {
return object_->find(key) != object_->end();
} else {
throw std::runtime_error("contains can only be called on arrays and objects: " + dump());
}
}
bool contains(const Value & value) const {
if (is_null())
throw std::runtime_error("Undefined value or reference");
if (array_) {
for (const auto& item : *array_) {
if (item.to_bool() && item == value) return true;
}
return false;
} else if (object_) {
if (!value.is_hashable()) throw std::runtime_error("Unashable type: " + value.dump());
return object_->find(value.primitive_) != object_->end();
} else {
throw std::runtime_error("contains can only be called on arrays and objects: " + dump());
}
}
void erase(size_t index) {
if (!array_) throw std::runtime_error("Value is not an array: " + dump());
array_->erase(array_->begin() + index);
}
void erase(const std::string & key) {
if (!object_) throw std::runtime_error("Value is not an object: " + dump());
object_->erase(key);
}
const Value& at(const Value & index) const {
return const_cast<Value*>(this)->at(index);
}
Value& at(const Value & index) {
if (!index.is_hashable()) throw std::runtime_error("Unashable type: " + dump());
if (is_array()) return array_->at(index.get<int>());
if (is_object()) return object_->at(index.primitive_);
throw std::runtime_error("Value is not an array or object: " + dump());
}
const Value& at(size_t index) const {
return const_cast<Value*>(this)->at(index);
}
Value& at(size_t index) {
if (is_null())
throw std::runtime_error("Undefined value or reference");
if (is_array()) return array_->at(index);
if (is_object()) return object_->at(index);
throw std::runtime_error("Value is not an array or object: " + dump());
}
template <typename T>
T get(const std::string & key, T default_value) const {
if (!contains(key)) return default_value;
return at(key).get<T>();
}
template <typename T>
T get() const {
if (is_primitive()) return primitive_.get<T>();
throw std::runtime_error("get<T> not defined for this value type: " + dump());
}
std::string dump(int indent=-1, bool to_json=false) const {
std::ostringstream out;
dump(out, indent, 0, to_json);
return out.str();
}
Value operator-() const {
if (is_number_integer())
return -get<int64_t>();
else
return -get<double>();
}
std::string to_str() const {
if (is_string()) return get<std::string>();
if (is_number_integer()) return std::to_string(get<int64_t>());
if (is_number_float()) return std::to_string(get<double>());
if (is_boolean()) return get<bool>() ? "True" : "False";
if (is_null()) return "None";
return dump();
}
Value operator+(const Value& rhs) const {
if (is_string() || rhs.is_string()) {
return to_str() + rhs.to_str();
} else if (is_number_integer() && rhs.is_number_integer()) {
return get<int64_t>() + rhs.get<int64_t>();
} else if (is_array() && rhs.is_array()) {
auto res = Value::array();
for (const auto& item : *array_) res.push_back(item);
for (const auto& item : *rhs.array_) res.push_back(item);
return res;
} else {
return get<double>() + rhs.get<double>();
}
}
Value operator-(const Value& rhs) const {
if (is_number_integer() && rhs.is_number_integer())
return get<int64_t>() - rhs.get<int64_t>();
else
return get<double>() - rhs.get<double>();
}
Value operator*(const Value& rhs) const {
if (is_string() && rhs.is_number_integer()) {
std::ostringstream out;
for (int64_t i = 0, n = rhs.get<int64_t>(); i < n; ++i) {
out << to_str();
}
return out.str();
}
else if (is_number_integer() && rhs.is_number_integer())
return get<int64_t>() * rhs.get<int64_t>();
else
return get<double>() * rhs.get<double>();
}
Value operator/(const Value& rhs) const {
if (is_number_integer() && rhs.is_number_integer())
return get<int64_t>() / rhs.get<int64_t>();
else
return get<double>() / rhs.get<double>();
}
Value operator%(const Value& rhs) const {
return get<int64_t>() % rhs.get<int64_t>();
}
};
struct ArgumentsValue {
std::vector<Value> args;
std::vector<std::pair<std::string, Value>> kwargs;
bool has_named(const std::string & name) {
for (const auto & p : kwargs) {
if (p.first == name) return true;
}
return false;
}
Value get_named(const std::string & name) {
for (const auto & [key, value] : kwargs) {
if (key == name) return value;
}
return Value();
}
bool empty() {
return args.empty() && kwargs.empty();
}
void expectArgs(const std::string & method_name, const std::pair<size_t, size_t> & pos_count, const std::pair<size_t, size_t> & kw_count) {
if (args.size() < pos_count.first || args.size() > pos_count.second || kwargs.size() < kw_count.first || kwargs.size() > kw_count.second) {
std::ostringstream out;
out << method_name << " must have between " << pos_count.first << " and " << pos_count.second << " positional arguments and between " << kw_count.first << " and " << kw_count.second << " keyword arguments";
throw std::runtime_error(out.str());
}
}
};
template <>
inline json Value::get<json>() const {
if (is_primitive()) return primitive_;
if (is_null()) return json();
if (array_) {
std::vector<json> res;
for (const auto& item : *array_) {
res.push_back(item.get<json>());
}
return res;
}
if (object_) {
json res = json::object();
for (const auto& [key, value] : *object_) {
if (key.is_string()) {
res[key.get<std::string>()] = value.get<json>();
} else if (key.is_primitive()) {
res[key.dump()] = value.get<json>();
} else {
throw std::runtime_error("Invalid key type for conversion to JSON: " + key.dump());
}
}
if (is_callable()) {
res["__callable__"] = true;
}
return res;
}
throw std::runtime_error("get<json> not defined for this value type: " + dump());
}
} // namespace minja
namespace std {
template <>
struct hash<minja::Value> {
size_t operator()(const minja::Value & v) const {
if (!v.is_hashable())
throw std::runtime_error("Unsupported type for hashing: " + v.dump());
return std::hash<json>()(v.get<json>());
}
};
} // namespace std
namespace minja {
static std::string error_location_suffix(const std::string & source, size_t pos) {
auto get_line = [&](size_t line) {
auto start = source.begin();
for (size_t i = 1; i < line; ++i) {
start = std::find(start, source.end(), '\n') + 1;
}
auto end = std::find(start, source.end(), '\n');
return std::string(start, end);
};
auto start = source.begin();
auto end = source.end();
auto it = start + pos;
auto line = std::count(start, it, '\n') + 1;
auto max_line = std::count(start, end, '\n') + 1;
auto col = pos - std::string(start, it).rfind('\n');
std::ostringstream out;
out << " at row " << line << ", column " << col << ":\n";
if (line > 1) out << get_line(line - 1) << "\n";
out << get_line(line) << "\n";
out << std::string(col - 1, ' ') << "^\n";
if (line < max_line) out << get_line(line + 1) << "\n";
return out.str();
}
class Context : public std::enable_shared_from_this<Context> {
protected:
Value values_;
std::shared_ptr<Context> parent_;
public:
Context(Value && values, const std::shared_ptr<Context> & parent = nullptr) : values_(std::move(values)), parent_(parent) {
if (!values_.is_object()) throw std::runtime_error("Context values must be an object: " + values_.dump());
}
virtual ~Context() {}
static std::shared_ptr<Context> builtins();
static std::shared_ptr<Context> make(Value && values, const std::shared_ptr<Context> & parent = builtins());
std::vector<Value> keys() {
return values_.keys();
}
virtual Value get(const Value & key) {
if (values_.contains(key)) return values_.at(key);
if (parent_) return parent_->get(key);
return Value();
}
virtual Value & at(const Value & key) {
if (values_.contains(key)) return values_.at(key);
if (parent_) return parent_->at(key);
throw std::runtime_error("Undefined variable: " + key.dump());
}
virtual bool contains(const Value & key) {
if (values_.contains(key)) return true;
if (parent_) return parent_->contains(key);
return false;
}
virtual void set(const Value & key, const Value & value) {
values_.set(key, value);
}
};
struct Location {
std::shared_ptr<std::string> source;
size_t pos;
};
class Expression {
protected:
virtual Value do_evaluate(const std::shared_ptr<Context> & context) const = 0;
public:
using Parameters = std::vector<std::pair<std::string, std::shared_ptr<Expression>>>;
Location location;
Expression(const Location & location) : location(location) {}
virtual ~Expression() = default;
Value evaluate(const std::shared_ptr<Context> & context) const {
try {
return do_evaluate(context);
} catch (const std::exception & e) {
std::ostringstream out;
out << e.what();
if (location.source) out << error_location_suffix(*location.source, location.pos);
throw std::runtime_error(out.str());
}
}
};
class VariableExpr : public Expression {
std::string name;
public:
VariableExpr(const Location & location, const std::string& n)
: Expression(location), name(n) {}
std::string get_name() const { return name; }
Value do_evaluate(const std::shared_ptr<Context> & context) const override {
if (!context->contains(name)) {
return Value();
}
return context->at(name);
}
};
static void destructuring_assign(const std::vector<std::string> & var_names, const std::shared_ptr<Context> & context, Value& item) {
if (var_names.size() == 1) {
Value name(var_names[0]);
context->set(name, item);
} else {
if (!item.is_array() || item.size() != var_names.size()) {
throw std::runtime_error("Mismatched number of variables and items in destructuring assignment");
}
for (size_t i = 0; i < var_names.size(); ++i) {
context->set(var_names[i], item.at(i));
}
}
}
enum SpaceHandling { Keep, Strip, StripSpaces, StripNewline };
class TemplateToken {
public:
enum class Type { Text, Expression, If, Else, Elif, EndIf, For, EndFor, Generation, EndGeneration, Set, EndSet, Comment, Macro, EndMacro, Filter, EndFilter, Break, Continue };
static std::string typeToString(Type t) {
switch (t) {
case Type::Text: return "text";
case Type::Expression: return "expression";
case Type::If: return "if";
case Type::Else: return "else";
case Type::Elif: return "elif";
case Type::EndIf: return "endif";
case Type::For: return "for";
case Type::EndFor: return "endfor";
case Type::Set: return "set";
case Type::EndSet: return "endset";
case Type::Comment: return "comment";
case Type::Macro: return "macro";
case Type::EndMacro: return "endmacro";
case Type::Filter: return "filter";
case Type::EndFilter: return "endfilter";
case Type::Generation: return "generation";
case Type::EndGeneration: return "endgeneration";
case Type::Break: return "break";
case Type::Continue: return "continue";
}
return "Unknown";
}
TemplateToken(Type type, const Location & location, SpaceHandling pre, SpaceHandling post) : type(type), location(location), pre_space(pre), post_space(post) {}
virtual ~TemplateToken() = default;
Type type;
Location location;
SpaceHandling pre_space = SpaceHandling::Keep;
SpaceHandling post_space = SpaceHandling::Keep;
};
struct TextTemplateToken : public TemplateToken {
std::string text;
TextTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post, const std::string& t) : TemplateToken(Type::Text, location, pre, post), text(t) {}
};
struct ExpressionTemplateToken : public TemplateToken {
std::shared_ptr<Expression> expr;
ExpressionTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post, std::shared_ptr<Expression> && e) : TemplateToken(Type::Expression, location, pre, post), expr(std::move(e)) {}
};
struct IfTemplateToken : public TemplateToken {
std::shared_ptr<Expression> condition;
IfTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post, std::shared_ptr<Expression> && c) : TemplateToken(Type::If, location, pre, post), condition(std::move(c)) {}
};
struct ElifTemplateToken : public TemplateToken {
std::shared_ptr<Expression> condition;
ElifTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post, std::shared_ptr<Expression> && c) : TemplateToken(Type::Elif, location, pre, post), condition(std::move(c)) {}
};
struct ElseTemplateToken : public TemplateToken {
ElseTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post) : TemplateToken(Type::Else, location, pre, post) {}
};
struct EndIfTemplateToken : public TemplateToken {
EndIfTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post) : TemplateToken(Type::EndIf, location, pre, post) {}
};
struct MacroTemplateToken : public TemplateToken {
std::shared_ptr<VariableExpr> name;
Expression::Parameters params;
MacroTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post, std::shared_ptr<VariableExpr> && n, Expression::Parameters && p)
: TemplateToken(Type::Macro, location, pre, post), name(std::move(n)), params(std::move(p)) {}
};
struct EndMacroTemplateToken : public TemplateToken {
EndMacroTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post) : TemplateToken(Type::EndMacro, location, pre, post) {}
};
struct FilterTemplateToken : public TemplateToken {
std::shared_ptr<Expression> filter;
FilterTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post, std::shared_ptr<Expression> && filter)
: TemplateToken(Type::Filter, location, pre, post), filter(std::move(filter)) {}
};
struct EndFilterTemplateToken : public TemplateToken {
EndFilterTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post) : TemplateToken(Type::EndFilter, location, pre, post) {}
};
struct ForTemplateToken : public TemplateToken {
std::vector<std::string> var_names;
std::shared_ptr<Expression> iterable;
std::shared_ptr<Expression> condition;
bool recursive;
ForTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post, const std::vector<std::string> & vns, std::shared_ptr<Expression> && iter,
std::shared_ptr<Expression> && c, bool r)
: TemplateToken(Type::For, location, pre, post), var_names(vns), iterable(std::move(iter)), condition(std::move(c)), recursive(r) {}
};
struct EndForTemplateToken : public TemplateToken {
EndForTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post) : TemplateToken(Type::EndFor, location, pre, post) {}
};
struct GenerationTemplateToken : public TemplateToken {
GenerationTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post) : TemplateToken(Type::Generation, location, pre, post) {}
};
struct EndGenerationTemplateToken : public TemplateToken {
EndGenerationTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post) : TemplateToken(Type::EndGeneration, location, pre, post) {}
};
struct SetTemplateToken : public TemplateToken {
std::string ns;
std::vector<std::string> var_names;
std::shared_ptr<Expression> value;
SetTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post, const std::string & ns, const std::vector<std::string> & vns, std::shared_ptr<Expression> && v)
: TemplateToken(Type::Set, location, pre, post), ns(ns), var_names(vns), value(std::move(v)) {}
};
struct EndSetTemplateToken : public TemplateToken {
EndSetTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post) : TemplateToken(Type::EndSet, location, pre, post) {}
};
struct CommentTemplateToken : public TemplateToken {
std::string text;
CommentTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post, const std::string& t) : TemplateToken(Type::Comment, location, pre, post), text(t) {}
};
enum class LoopControlType { Break, Continue };
class LoopControlException : public std::runtime_error {
public:
LoopControlType control_type;
LoopControlException(const std::string & message, LoopControlType control_type) : std::runtime_error(message), control_type(control_type) {}
LoopControlException(LoopControlType control_type)
: std::runtime_error((control_type == LoopControlType::Continue ? "continue" : "break") + std::string(" outside of a loop")),
control_type(control_type) {}
};
struct LoopControlTemplateToken : public TemplateToken {
LoopControlType control_type;
LoopControlTemplateToken(const Location & location, SpaceHandling pre, SpaceHandling post, LoopControlType control_type) : TemplateToken(Type::Break, location, pre, post), control_type(control_type) {}
};
class TemplateNode {
Location location_;
protected:
virtual void do_render(std::ostringstream & out, const std::shared_ptr<Context> & context) const = 0;
public:
TemplateNode(const Location & location) : location_(location) {}
void render(std::ostringstream & out, const std::shared_ptr<Context> & context) const {
try {
do_render(out, context);
} catch (const LoopControlException & e) {
// TODO: make stack creation lazy. Only needed if it was thrown outside of a loop.
std::ostringstream err;
err << e.what();
if (location_.source) err << error_location_suffix(*location_.source, location_.pos);
throw LoopControlException(err.str(), e.control_type);
} catch (const std::exception & e) {
std::ostringstream err;
err << e.what();
if (location_.source) err << error_location_suffix(*location_.source, location_.pos);
throw std::runtime_error(err.str());
}
}
const Location & location() const { return location_; }
virtual ~TemplateNode() = default;
std::string render(const std::shared_ptr<Context> & context) const {
std::ostringstream out;
render(out, context);
return out.str();
}
};
class SequenceNode : public TemplateNode {
std::vector<std::shared_ptr<TemplateNode>> children;
public:
SequenceNode(const Location & location, std::vector<std::shared_ptr<TemplateNode>> && c)
: TemplateNode(location), children(std::move(c)) {}
void do_render(std::ostringstream & out, const std::shared_ptr<Context> & context) const override {
for (const auto& child : children) child->render(out, context);
}
};
class TextNode : public TemplateNode {
std::string text;
public:
TextNode(const Location & location, const std::string& t) : TemplateNode(location), text(t) {}
void do_render(std::ostringstream & out, const std::shared_ptr<Context> &) const override {
out << text;
}
};
class ExpressionNode : public TemplateNode {
std::shared_ptr<Expression> expr;
public:
ExpressionNode(const Location & location, std::shared_ptr<Expression> && e) : TemplateNode(location), expr(std::move(e)) {}
void do_render(std::ostringstream & out, const std::shared_ptr<Context> & context) const override {
if (!expr) throw std::runtime_error("ExpressionNode.expr is null");
auto result = expr->evaluate(context);
if (result.is_string()) {
out << result.get<std::string>();
} else if (result.is_boolean()) {
out << (result.get<bool>() ? "True" : "False");
} else if (!result.is_null()) {
out << result.dump();
}
}
};
class IfNode : public TemplateNode {
std::vector<std::pair<std::shared_ptr<Expression>, std::shared_ptr<TemplateNode>>> cascade;
public:
IfNode(const Location & location, std::vector<std::pair<std::shared_ptr<Expression>, std::shared_ptr<TemplateNode>>> && c)
: TemplateNode(location), cascade(std::move(c)) {}
void do_render(std::ostringstream & out, const std::shared_ptr<Context> & context) const override {
for (const auto& branch : cascade) {
auto enter_branch = true;
if (branch.first) {
enter_branch = branch.first->evaluate(context).to_bool();
}
if (enter_branch) {
if (!branch.second) throw std::runtime_error("IfNode.cascade.second is null");
branch.second->render(out, context);
return;
}
}
}
};
class LoopControlNode : public TemplateNode {
LoopControlType control_type_;
public:
LoopControlNode(const Location & location, LoopControlType control_type) : TemplateNode(location), control_type_(control_type) {}
void do_render(std::ostringstream &, const std::shared_ptr<Context> &) const override {
throw LoopControlException(control_type_);
}
};
class ForNode : public TemplateNode {
std::vector<std::string> var_names;
std::shared_ptr<Expression> iterable;
std::shared_ptr<Expression> condition;
std::shared_ptr<TemplateNode> body;
bool recursive;
std::shared_ptr<TemplateNode> else_body;
public:
ForNode(const Location & location, std::vector<std::string> && var_names, std::shared_ptr<Expression> && iterable,
std::shared_ptr<Expression> && condition, std::shared_ptr<TemplateNode> && body, bool recursive, std::shared_ptr<TemplateNode> && else_body)
: TemplateNode(location), var_names(var_names), iterable(std::move(iterable)), condition(std::move(condition)), body(std::move(body)), recursive(recursive), else_body(std::move(else_body)) {}
void do_render(std::ostringstream & out, const std::shared_ptr<Context> & context) const override {
// https://jinja.palletsprojects.com/en/3.0.x/templates/#for
if (!iterable) throw std::runtime_error("ForNode.iterable is null");
if (!body) throw std::runtime_error("ForNode.body is null");
auto iterable_value = iterable->evaluate(context);
Value::CallableType loop_function;
std::function<void(Value&)> visit = [&](Value& iter) {
auto filtered_items = Value::array();
if (!iter.is_null()) {
if (!iterable_value.is_iterable()) {
throw std::runtime_error("For loop iterable must be iterable: " + iterable_value.dump());
}
iterable_value.for_each([&](Value & item) {
destructuring_assign(var_names, context, item);
if (!condition || condition->evaluate(context).to_bool()) {
filtered_items.push_back(item);
}
});
}
if (filtered_items.empty()) {
if (else_body) {
else_body->render(out, context);
}
} else {
auto loop = recursive ? Value::callable(loop_function) : Value::object();
loop.set("length", (int64_t) filtered_items.size());
size_t cycle_index = 0;
loop.set("cycle", Value::callable([&](const std::shared_ptr<Context> &, ArgumentsValue & args) {
if (args.args.empty() || !args.kwargs.empty()) {
throw std::runtime_error("cycle() expects at least 1 positional argument and no named arg");
}
auto item = args.args[cycle_index];
cycle_index = (cycle_index + 1) % args.args.size();
return item;
}));
auto loop_context = Context::make(Value::object(), context);
loop_context->set("loop", loop);
for (size_t i = 0, n = filtered_items.size(); i < n; ++i) {
auto & item = filtered_items.at(i);
destructuring_assign(var_names, loop_context, item);
loop.set("index", (int64_t) i + 1);
loop.set("index0", (int64_t) i);
loop.set("revindex", (int64_t) (n - i));
loop.set("revindex0", (int64_t) (n - i - 1));
loop.set("length", (int64_t) n);
loop.set("first", i == 0);
loop.set("last", i == (n - 1));
loop.set("previtem", i > 0 ? filtered_items.at(i - 1) : Value());
loop.set("nextitem", i < n - 1 ? filtered_items.at(i + 1) : Value());
try {
body->render(out, loop_context);
} catch (const LoopControlException & e) {
if (e.control_type == LoopControlType::Break) break;
if (e.control_type == LoopControlType::Continue) continue;
}
}
}
};
if (recursive) {
loop_function = [&](const std::shared_ptr<Context> &, ArgumentsValue & args) {
if (args.args.size() != 1 || !args.kwargs.empty() || !args.args[0].is_array()) {
throw std::runtime_error("loop() expects exactly 1 positional iterable argument");
}
auto & items = args.args[0];
visit(items);
return Value();
};
}
visit(iterable_value);
}
};
class MacroNode : public TemplateNode {
std::shared_ptr<VariableExpr> name;
Expression::Parameters params;
std::shared_ptr<TemplateNode> body;
std::unordered_map<std::string, size_t> named_param_positions;
public:
MacroNode(const Location & location, std::shared_ptr<VariableExpr> && n, Expression::Parameters && p, std::shared_ptr<TemplateNode> && b)
: TemplateNode(location), name(std::move(n)), params(std::move(p)), body(std::move(b)) {
for (size_t i = 0; i < params.size(); ++i) {
const auto & name = params[i].first;
if (!name.empty()) {
named_param_positions[name] = i;
}
}
}
void do_render(std::ostringstream &, const std::shared_ptr<Context> & macro_context) const override {
if (!name) throw std::runtime_error("MacroNode.name is null");
if (!body) throw std::runtime_error("MacroNode.body is null");
auto callable = Value::callable([&](const std::shared_ptr<Context> & context, ArgumentsValue & args) {
auto call_context = macro_context;
std::vector<bool> param_set(params.size(), false);
for (size_t i = 0, n = args.args.size(); i < n; i++) {
auto & arg = args.args[i];
if (i >= params.size()) throw std::runtime_error("Too many positional arguments for macro " + name->get_name());
param_set[i] = true;
auto & param_name = params[i].first;
call_context->set(param_name, arg);
}
for (auto & [arg_name, value] : args.kwargs) {
auto it = named_param_positions.find(arg_name);
if (it == named_param_positions.end()) throw std::runtime_error("Unknown parameter name for macro " + name->get_name() + ": " + arg_name);
call_context->set(arg_name, value);
param_set[it->second] = true;
}
// Set default values for parameters that were not passed
for (size_t i = 0, n = params.size(); i < n; i++) {
if (!param_set[i] && params[i].second != nullptr) {
auto val = params[i].second->evaluate(context);
call_context->set(params[i].first, val);
}
}
return body->render(call_context);
});
macro_context->set(name->get_name(), callable);
}
};
class FilterNode : public TemplateNode {
std::shared_ptr<Expression> filter;
std::shared_ptr<TemplateNode> body;
public:
FilterNode(const Location & location, std::shared_ptr<Expression> && f, std::shared_ptr<TemplateNode> && b)
: TemplateNode(location), filter(std::move(f)), body(std::move(b)) {}
void do_render(std::ostringstream & out, const std::shared_ptr<Context> & context) const override {
if (!filter) throw std::runtime_error("FilterNode.filter is null");
if (!body) throw std::runtime_error("FilterNode.body is null");
auto filter_value = filter->evaluate(context);
if (!filter_value.is_callable()) {
throw std::runtime_error("Filter must be a callable: " + filter_value.dump());
}
std::string rendered_body = body->render(context);
ArgumentsValue filter_args = {{Value(rendered_body)}, {}};
auto result = filter_value.call(context, filter_args);
out << result.to_str();
}
};
class SetNode : public TemplateNode {
std::string ns;
std::vector<std::string> var_names;
std::shared_ptr<Expression> value;
public:
SetNode(const Location & location, const std::string & ns, const std::vector<std::string> & vns, std::shared_ptr<Expression> && v)
: TemplateNode(location), ns(ns), var_names(vns), value(std::move(v)) {}
void do_render(std::ostringstream &, const std::shared_ptr<Context> & context) const override {
if (!value) throw std::runtime_error("SetNode.value is null");
if (!ns.empty()) {
if (var_names.size() != 1) {
throw std::runtime_error("Namespaced set only supports a single variable name");
}
auto & name = var_names[0];
auto ns_value = context->get(ns);
if (!ns_value.is_object()) throw std::runtime_error("Namespace '" + ns + "' is not an object");
ns_value.set(name, this->value->evaluate(context));
} else {
auto val = value->evaluate(context);
destructuring_assign(var_names, context, val);
}
}
};
class SetTemplateNode : public TemplateNode {
std::string name;
std::shared_ptr<TemplateNode> template_value;
public:
SetTemplateNode(const Location & location, const std::string & name, std::shared_ptr<TemplateNode> && tv)
: TemplateNode(location), name(name), template_value(std::move(tv)) {}
void do_render(std::ostringstream &, const std::shared_ptr<Context> & context) const override {
if (!template_value) throw std::runtime_error("SetTemplateNode.template_value is null");
Value value { template_value->render(context) };
context->set(name, value);
}
};
class IfExpr : public Expression {
std::shared_ptr<Expression> condition;
std::shared_ptr<Expression> then_expr;
std::shared_ptr<Expression> else_expr;
public:
IfExpr(const Location & location, std::shared_ptr<Expression> && c, std::shared_ptr<Expression> && t, std::shared_ptr<Expression> && e)
: Expression(location), condition(std::move(c)), then_expr(std::move(t)), else_expr(std::move(e)) {}
Value do_evaluate(const std::shared_ptr<Context> & context) const override {
if (!condition) throw std::runtime_error("IfExpr.condition is null");
if (!then_expr) throw std::runtime_error("IfExpr.then_expr is null");
if (condition->evaluate(context).to_bool()) {
return then_expr->evaluate(context);
}
if (else_expr) {
return else_expr->evaluate(context);
}
return nullptr;
}
};
class LiteralExpr : public Expression {
Value value;
public:
LiteralExpr(const Location & location, const Value& v)
: Expression(location), value(v) {}
Value do_evaluate(const std::shared_ptr<Context> &) const override { return value; }
};
class ArrayExpr : public Expression {
std::vector<std::shared_ptr<Expression>> elements;
public:
ArrayExpr(const Location & location, std::vector<std::shared_ptr<Expression>> && e)
: Expression(location), elements(std::move(e)) {}
Value do_evaluate(const std::shared_ptr<Context> & context) const override {
auto result = Value::array();
for (const auto& e : elements) {
if (!e) throw std::runtime_error("Array element is null");
result.push_back(e->evaluate(context));
}
return result;
}
};
class DictExpr : public Expression {
std::vector<std::pair<std::shared_ptr<Expression>, std::shared_ptr<Expression>>> elements;
public:
DictExpr(const Location & location, std::vector<std::pair<std::shared_ptr<Expression>, std::shared_ptr<Expression>>> && e)
: Expression(location), elements(std::move(e)) {}
Value do_evaluate(const std::shared_ptr<Context> & context) const override {
auto result = Value::object();
for (const auto& [key, value] : elements) {
if (!key) throw std::runtime_error("Dict key is null");
if (!value) throw std::runtime_error("Dict value is null");
result.set(key->evaluate(context), value->evaluate(context));
}
return result;
}
};
class SliceExpr : public Expression {
public:
std::shared_ptr<Expression> start, end;
SliceExpr(const Location & location, std::shared_ptr<Expression> && s, std::shared_ptr<Expression> && e)
: Expression(location), start(std::move(s)), end(std::move(e)) {}
Value do_evaluate(const std::shared_ptr<Context> &) const override {
throw std::runtime_error("SliceExpr not implemented");
}
};
class SubscriptExpr : public Expression {
std::shared_ptr<Expression> base;
std::shared_ptr<Expression> index;
public:
SubscriptExpr(const Location & location, std::shared_ptr<Expression> && b, std::shared_ptr<Expression> && i)
: Expression(location), base(std::move(b)), index(std::move(i)) {}
Value do_evaluate(const std::shared_ptr<Context> & context) const override {
if (!base) throw std::runtime_error("SubscriptExpr.base is null");
if (!index) throw std::runtime_error("SubscriptExpr.index is null");
auto target_value = base->evaluate(context);
if (auto slice = dynamic_cast<SliceExpr*>(index.get())) {
auto start = slice->start ? slice->start->evaluate(context).get<int64_t>() : 0;
auto end = slice->end ? slice->end->evaluate(context).get<int64_t>() : (int64_t) target_value.size();
if (target_value.is_string()) {
std::string s = target_value.get<std::string>();
if (start < 0) start = s.size() + start;
if (end < 0) end = s.size() + end;
return s.substr(start, end - start);
} else if (target_value.is_array()) {
if (start < 0) start = target_value.size() + start;
if (end < 0) end = target_value.size() + end;
auto result = Value::array();
for (auto i = start; i < end; ++i) {
result.push_back(target_value.at(i));
}
return result;
} else {
throw std::runtime_error(target_value.is_null() ? "Cannot subscript null" : "Subscripting only supported on arrays and strings");
}
} else {
auto index_value = index->evaluate(context);
if (target_value.is_null()) {
if (auto t = dynamic_cast<VariableExpr*>(base.get())) {
throw std::runtime_error("'" + t->get_name() + "' is " + (context->contains(t->get_name()) ? "null" : "not defined"));
}
throw std::runtime_error("Trying to access property '" + index_value.dump() + "' on null!");
}
return target_value.get(index_value);
}
}
};
class UnaryOpExpr : public Expression {
public:
enum class Op { Plus, Minus, LogicalNot, Expansion, ExpansionDict };
std::shared_ptr<Expression> expr;
Op op;
UnaryOpExpr(const Location & location, std::shared_ptr<Expression> && e, Op o)
: Expression(location), expr(std::move(e)), op(o) {}
Value do_evaluate(const std::shared_ptr<Context> & context) const override {
if (!expr) throw std::runtime_error("UnaryOpExpr.expr is null");
auto e = expr->evaluate(context);
switch (op) {
case Op::Plus: return e;
case Op::Minus: return -e;
case Op::LogicalNot: return !e.to_bool();
case Op::Expansion:
case Op::ExpansionDict:
throw std::runtime_error("Expansion operator is only supported in function calls and collections");
}
throw std::runtime_error("Unknown unary operator");
}
};
class BinaryOpExpr : public Expression {
public:
enum class Op { StrConcat, Add, Sub, Mul, MulMul, Div, DivDiv, Mod, Eq, Ne, Lt, Gt, Le, Ge, And, Or, In, NotIn, Is, IsNot };
private:
std::shared_ptr<Expression> left;
std::shared_ptr<Expression> right;
Op op;
public:
BinaryOpExpr(const Location & location, std::shared_ptr<Expression> && l, std::shared_ptr<Expression> && r, Op o)
: Expression(location), left(std::move(l)), right(std::move(r)), op(o) {}
Value do_evaluate(const std::shared_ptr<Context> & context) const override {
if (!left) throw std::runtime_error("BinaryOpExpr.left is null");
if (!right) throw std::runtime_error("BinaryOpExpr.right is null");
auto l = left->evaluate(context);
auto do_eval = [&](const Value & l) -> Value {
if (op == Op::Is || op == Op::IsNot) {
auto t = dynamic_cast<VariableExpr*>(right.get());
if (!t) throw std::runtime_error("Right side of 'is' operator must be a variable");
auto eval = [&]() {
const auto & name = t->get_name();
if (name == "none") return l.is_null();
if (name == "boolean") return l.is_boolean();
if (name == "integer") return l.is_number_integer();
if (name == "float") return l.is_number_float();
if (name == "number") return l.is_number();
if (name == "string") return l.is_string();
if (name == "mapping") return l.is_object();
if (name == "iterable") return l.is_iterable();
if (name == "sequence") return l.is_array();
if (name == "defined") return !l.is_null();
throw std::runtime_error("Unknown type for 'is' operator: " + name);
};
auto value = eval();
return Value(op == Op::Is ? value : !value);
}
if (op == Op::And) {
if (!l.to_bool()) return Value(false);
return right->evaluate(context).to_bool();
} else if (op == Op::Or) {
if (l.to_bool()) return l;
return right->evaluate(context);
}
auto r = right->evaluate(context);
switch (op) {
case Op::StrConcat: return l.to_str() + r.to_str();
case Op::Add: return l + r;
case Op::Sub: return l - r;
case Op::Mul: return l * r;
case Op::Div: return l / r;
case Op::MulMul: return std::pow(l.get<double>(), r.get<double>());
case Op::DivDiv: return l.get<int64_t>() / r.get<int64_t>();
case Op::Mod: return l.get<int64_t>() % r.get<int64_t>();
case Op::Eq: return l == r;
case Op::Ne: return l != r;
case Op::Lt: return l < r;
case Op::Gt: return l > r;
case Op::Le: return l <= r;
case Op::Ge: return l >= r;
case Op::In: return (r.is_array() || r.is_object()) && r.contains(l);
case Op::NotIn: return !(r.is_array() && r.contains(l));
default: break;
}
throw std::runtime_error("Unknown binary operator");
};
if (l.is_callable()) {
return Value::callable([l, do_eval](const std::shared_ptr<Context> & context, ArgumentsValue & args) {
auto ll = l.call(context, args);
return do_eval(ll); //args[0].second);
});
} else {
return do_eval(l);
}
}
};
struct ArgumentsExpression {
std::vector<std::shared_ptr<Expression>> args;
std::vector<std::pair<std::string, std::shared_ptr<Expression>>> kwargs;
ArgumentsValue evaluate(const std::shared_ptr<Context> & context) const {
ArgumentsValue vargs;
for (const auto& arg : this->args) {
if (auto un_expr = std::dynamic_pointer_cast<UnaryOpExpr>(arg)) {
if (un_expr->op == UnaryOpExpr::Op::Expansion) {
auto array = un_expr->expr->evaluate(context);
if (!array.is_array()) {
throw std::runtime_error("Expansion operator only supported on arrays");
}
array.for_each([&](Value & value) {
vargs.args.push_back(value);
});
continue;
} else if (un_expr->op == UnaryOpExpr::Op::ExpansionDict) {
auto dict = un_expr->expr->evaluate(context);
if (!dict.is_object()) {
throw std::runtime_error("ExpansionDict operator only supported on objects");
}
dict.for_each([&](const Value & key) {
vargs.kwargs.push_back({key.get<std::string>(), dict.at(key)});
});
continue;
}
}
vargs.args.push_back(arg->evaluate(context));
}
for (const auto& [name, value] : this->kwargs) {
vargs.kwargs.push_back({name, value->evaluate(context)});
}
return vargs;
}
};
static std::string strip(const std::string & s) {
auto start = s.find_first_not_of(" \t\n\r");
if (start == std::string::npos) return "";
auto end = s.find_last_not_of(" \t\n\r");
return s.substr(start, end - start + 1);
}
static std::string html_escape(const std::string & s) {
std::string result;
result.reserve(s.size());
for (const auto & c : s) {
switch (c) {
case '&': result += "&"; break;
case '<': result += "<"; break;
case '>': result += ">"; break;
case '"': result += """; break;
case '\'': result += "'"; break;
default: result += c; break;
}
}
return result;
}
class MethodCallExpr : public Expression {
std::shared_ptr<Expression> object;
std::shared_ptr<VariableExpr> method;
ArgumentsExpression args;
public:
MethodCallExpr(const Location & location, std::shared_ptr<Expression> && obj, std::shared_ptr<VariableExpr> && m, ArgumentsExpression && a)
: Expression(location), object(std::move(obj)), method(std::move(m)), args(std::move(a)) {}
Value do_evaluate(const std::shared_ptr<Context> & context) const override {
if (!object) throw std::runtime_error("MethodCallExpr.object is null");
if (!method) throw std::runtime_error("MethodCallExpr.method is null");
auto obj = object->evaluate(context);
auto vargs = args.evaluate(context);
if (obj.is_null()) {
throw std::runtime_error("Trying to call method '" + method->get_name() + "' on null");
}
if (obj.is_array()) {
if (method->get_name() == "append") {
vargs.expectArgs("append method", {1, 1}, {0, 0});
obj.push_back(vargs.args[0]);
return Value();
} else if (method->get_name() == "pop") {
vargs.expectArgs("pop method", {0, 1}, {0, 0});
return obj.pop(vargs.args.empty() ? Value() : vargs.args[0]);
} else if (method->get_name() == "insert") {
vargs.expectArgs("insert method", {2, 2}, {0, 0});
auto index = vargs.args[0].get<int64_t>();
if (index < 0 || index > (int64_t) obj.size()) throw std::runtime_error("Index out of range for insert method");
obj.insert(index, vargs.args[1]);
return Value();
}
} else if (obj.is_object()) {
if (method->get_name() == "items") {
vargs.expectArgs("items method", {0, 0}, {0, 0});
auto result = Value::array();
for (const auto& key : obj.keys()) {
result.push_back(Value::array({key, obj.at(key)}));
}
return result;
} else if (method->get_name() == "pop") {
vargs.expectArgs("pop method", {1, 1}, {0, 0});
return obj.pop(vargs.args[0]);
} else if (method->get_name() == "get") {
vargs.expectArgs("get method", {1, 2}, {0, 0});
auto key = vargs.args[0];
if (vargs.args.size() == 1) {
return obj.contains(key) ? obj.at(key) : Value();
} else {
return obj.contains(key) ? obj.at(key) : vargs.args[1];
}
} else if (obj.contains(method->get_name())) {
auto callable = obj.at(method->get_name());
if (!callable.is_callable()) {
throw std::runtime_error("Property '" + method->get_name() + "' is not callable");
}
return callable.call(context, vargs);
}
} else if (obj.is_string()) {
auto str = obj.get<std::string>();
if (method->get_name() == "strip") {
vargs.expectArgs("strip method", {0, 0}, {0, 0});
return Value(strip(str));
} else if (method->get_name() == "endswith") {
vargs.expectArgs("endswith method", {1, 1}, {0, 0});
auto suffix = vargs.args[0].get<std::string>();
return suffix.length() <= str.length() && std::equal(suffix.rbegin(), suffix.rend(), str.rbegin());
} else if (method->get_name() == "title") {
vargs.expectArgs("title method", {0, 0}, {0, 0});
auto res = str;
for (size_t i = 0, n = res.size(); i < n; ++i) {
if (i == 0 || std::isspace(res[i - 1])) res[i] = std::toupper(res[i]);
else res[i] = std::tolower(res[i]);
}
return res;
}
}
throw std::runtime_error("Unknown method: " + method->get_name());
}
};
class CallExpr : public Expression {
public:
std::shared_ptr<Expression> object;
ArgumentsExpression args;
CallExpr(const Location & location, std::shared_ptr<Expression> && obj, ArgumentsExpression && a)
: Expression(location), object(std::move(obj)), args(std::move(a)) {}
Value do_evaluate(const std::shared_ptr<Context> & context) const override {
if (!object) throw std::runtime_error("CallExpr.object is null");
auto obj = object->evaluate(context);
if (!obj.is_callable()) {
throw std::runtime_error("Object is not callable: " + obj.dump(2));
}
auto vargs = args.evaluate(context);
return obj.call(context, vargs);
}
};
class FilterExpr : public Expression {
std::vector<std::shared_ptr<Expression>> parts;
public:
FilterExpr(const Location & location, std::vector<std::shared_ptr<Expression>> && p)
: Expression(location), parts(std::move(p)) {}
Value do_evaluate(const std::shared_ptr<Context> & context) const override {
Value result;
bool first = true;
for (const auto& part : parts) {
if (!part) throw std::runtime_error("FilterExpr.part is null");
if (first) {
first = false;
result = part->evaluate(context);
} else {
if (auto ce = dynamic_cast<CallExpr*>(part.get())) {
auto target = ce->object->evaluate(context);
ArgumentsValue args = ce->args.evaluate(context);
args.args.insert(args.args.begin(), result);
result = target.call(context, args);
} else {
auto callable = part->evaluate(context);
ArgumentsValue args;
args.args.insert(args.args.begin(), result);
result = callable.call(context, args);
}
}
}
return result;
}
void prepend(std::shared_ptr<Expression> && e) {
parts.insert(parts.begin(), std::move(e));
}
};
class Parser {
private:
using CharIterator = std::string::const_iterator;
std::shared_ptr<std::string> template_str;
CharIterator start, end, it;
Options options;
Parser(const std::shared_ptr<std::string>& template_str, const Options & options) : template_str(template_str), options(options) {
if (!template_str) throw std::runtime_error("Template string is null");
start = it = this->template_str->begin();
end = this->template_str->end();
}
bool consumeSpaces(SpaceHandling space_handling = SpaceHandling::Strip) {
if (space_handling == SpaceHandling::Strip) {
while (it != end && std::isspace(*it)) ++it;
}
return true;
}
std::unique_ptr<std::string> parseString() {
auto doParse = [&](char quote) -> std::unique_ptr<std::string> {
if (it == end || *it != quote) return nullptr;
std::string result;
bool escape = false;
for (++it; it != end; ++it) {
if (escape) {
escape = false;
switch (*it) {
case 'n': result += '\n'; break;
case 'r': result += '\r'; break;
case 't': result += '\t'; break;
case 'b': result += '\b'; break;
case 'f': result += '\f'; break;
case '\\': result += '\\'; break;
default:
if (*it == quote) {
result += quote;
} else {
result += *it;
}
break;
}
} else if (*it == '\\') {
escape = true;
} else if (*it == quote) {
++it;
return std::make_unique<std::string>(std::move(result));
} else {
result += *it;
}
}
return nullptr;
};
consumeSpaces();
if (it == end) return nullptr;
if (*it == '"') return doParse('"');
if (*it == '\'') return doParse('\'');
return nullptr;
}
json parseNumber(CharIterator& it, const CharIterator& end) {
auto before = it;
consumeSpaces();
auto start = it;
bool hasDecimal = false;
bool hasExponent = false;
if (it != end && (*it == '-' || *it == '+')) ++it;
while (it != end) {
if (std::isdigit(*it)) {
++it;
} else if (*it == '.') {
if (hasDecimal) throw std::runtime_error("Multiple decimal points");
hasDecimal = true;
++it;
} else if (it != start && (*it == 'e' || *it == 'E')) {
if (hasExponent) throw std::runtime_error("Multiple exponents");
hasExponent = true;
++it;
} else {
break;
}
}
if (start == it) {
it = before;
return json(); // No valid characters found
}
std::string str(start, it);
try {
return json::parse(str);
} catch (json::parse_error& e) {
throw std::runtime_error("Failed to parse number: '" + str + "' (" + std::string(e.what()) + ")");
return json();
}
}
/** integer, float, bool, string */
std::shared_ptr<Value> parseConstant() {
auto start = it;
consumeSpaces();
if (it == end) return nullptr;
if (*it == '"' || *it == '\'') {
auto str = parseString();
if (str) return std::make_shared<Value>(*str);
}
static std::regex prim_tok(R"(true\b|True\b|false\b|False\b|None\b)");
auto token = consumeToken(prim_tok);
if (!token.empty()) {
if (token == "true" || token == "True") return std::make_shared<Value>(true);
if (token == "false" || token == "False") return std::make_shared<Value>(false);
if (token == "None") return std::make_shared<Value>(nullptr);
throw std::runtime_error("Unknown constant token: " + token);
}
auto number = parseNumber(it, end);
if (!number.is_null()) return std::make_shared<Value>(number);
it = start;
return nullptr;
}
class expression_parsing_error : public std::runtime_error {
const CharIterator it;
public:
expression_parsing_error(const std::string & message, const CharIterator & it)
: std::runtime_error(message), it(it) {}
size_t get_pos(const CharIterator & begin) const {
return std::distance(begin, it);
}
};
bool peekSymbols(const std::vector<std::string> & symbols) const {
for (const auto & symbol : symbols) {
if (std::distance(it, end) >= (int64_t) symbol.size() && std::string(it, it + symbol.size()) == symbol) {
return true;
}
}
return false;
}
std::vector<std::string> consumeTokenGroups(const std::regex & regex, SpaceHandling space_handling = SpaceHandling::Strip) {
auto start = it;
consumeSpaces(space_handling);
std::smatch match;
if (std::regex_search(it, end, match, regex) && match.position() == 0) {
it += match[0].length();
std::vector<std::string> ret;
for (size_t i = 0, n = match.size(); i < n; ++i) {
ret.push_back(match[i].str());
}
return ret;
}
it = start;
return {};
}
std::string consumeToken(const std::regex & regex, SpaceHandling space_handling = SpaceHandling::Strip) {
auto start = it;
consumeSpaces(space_handling);
std::smatch match;
if (std::regex_search(it, end, match, regex) && match.position() == 0) {
it += match[0].length();
return match[0].str();
}
it = start;
return "";
}
std::string consumeToken(const std::string & token, SpaceHandling space_handling = SpaceHandling::Strip) {
auto start = it;
consumeSpaces(space_handling);
if (std::distance(it, end) >= (int64_t) token.size() && std::string(it, it + token.size()) == token) {
it += token.size();
return token;
}
it = start;
return "";
}
std::shared_ptr<Expression> parseExpression(bool allow_if_expr = true) {
auto left = parseLogicalOr();
if (it == end) return left;
if (!allow_if_expr) return left;
static std::regex if_tok(R"(if\b)");
if (consumeToken(if_tok).empty()) {
return left;
}
auto location = get_location();
auto [condition, else_expr] = parseIfExpression();
return std::make_shared<IfExpr>(location, std::move(condition), std::move(left), std::move(else_expr));
}
Location get_location() const {
return {template_str, (size_t) std::distance(start, it)};
}
std::pair<std::shared_ptr<Expression>, std::shared_ptr<Expression>> parseIfExpression() {
auto condition = parseLogicalOr();
if (!condition) throw std::runtime_error("Expected condition expression");
static std::regex else_tok(R"(else\b)");
std::shared_ptr<Expression> else_expr;
if (!consumeToken(else_tok).empty()) {
else_expr = parseExpression();
if (!else_expr) throw std::runtime_error("Expected 'else' expression");
}
return std::pair(std::move(condition), std::move(else_expr));
}
std::shared_ptr<Expression> parseLogicalOr() {
auto left = parseLogicalAnd();
if (!left) throw std::runtime_error("Expected left side of 'logical or' expression");
static std::regex or_tok(R"(or\b)");
auto location = get_location();
while (!consumeToken(or_tok).empty()) {
auto right = parseLogicalAnd();
if (!right) throw std::runtime_error("Expected right side of 'or' expression");
left = std::make_shared<BinaryOpExpr>(location, std::move(left), std::move(right), BinaryOpExpr::Op::Or);
}
return left;
}
std::shared_ptr<Expression> parseLogicalNot() {
static std::regex not_tok(R"(not\b)");
auto location = get_location();
if (!consumeToken(not_tok).empty()) {
auto sub = parseLogicalNot();
if (!sub) throw std::runtime_error("Expected expression after 'not' keyword");
return std::make_shared<UnaryOpExpr>(location, std::move(sub), UnaryOpExpr::Op::LogicalNot);
}
return parseLogicalCompare();
}
std::shared_ptr<Expression> parseLogicalAnd() {
auto left = parseLogicalNot();
if (!left) throw std::runtime_error("Expected left side of 'logical and' expression");
static std::regex and_tok(R"(and\b)");
auto location = get_location();
while (!consumeToken(and_tok).empty()) {
auto right = parseLogicalNot();
if (!right) throw std::runtime_error("Expected right side of 'and' expression");
left = std::make_shared<BinaryOpExpr>(location, std::move(left), std::move(right), BinaryOpExpr::Op::And);
}
return left;
}
std::shared_ptr<Expression> parseLogicalCompare() {
auto left = parseStringConcat();
if (!left) throw std::runtime_error("Expected left side of 'logical compare' expression");
static std::regex compare_tok(R"(==|!=|<=?|>=?|in\b|is\b|not[\r\n\s]+in\b)");
static std::regex not_tok(R"(not\b)");
std::string op_str;
while (!(op_str = consumeToken(compare_tok)).empty()) {
auto location = get_location();
if (op_str == "is") {
auto negated = !consumeToken(not_tok).empty();
auto identifier = parseIdentifier();
if (!identifier) throw std::runtime_error("Expected identifier after 'is' keyword");
return std::make_shared<BinaryOpExpr>(
left->location,
std::move(left), std::move(identifier),
negated ? BinaryOpExpr::Op::IsNot : BinaryOpExpr::Op::Is);
}
auto right = parseStringConcat();
if (!right) throw std::runtime_error("Expected right side of 'logical compare' expression");
BinaryOpExpr::Op op;
if (op_str == "==") op = BinaryOpExpr::Op::Eq;
else if (op_str == "!=") op = BinaryOpExpr::Op::Ne;
else if (op_str == "<") op = BinaryOpExpr::Op::Lt;
else if (op_str == ">") op = BinaryOpExpr::Op::Gt;
else if (op_str == "<=") op = BinaryOpExpr::Op::Le;
else if (op_str == ">=") op = BinaryOpExpr::Op::Ge;
else if (op_str == "in") op = BinaryOpExpr::Op::In;
else if (op_str.substr(0, 3) == "not") op = BinaryOpExpr::Op::NotIn;
else throw std::runtime_error("Unknown comparison operator: " + op_str);
left = std::make_shared<BinaryOpExpr>(get_location(), std::move(left), std::move(right), op);
}
return left;
}
Expression::Parameters parseParameters() {
consumeSpaces();
if (consumeToken("(").empty()) throw std::runtime_error("Expected opening parenthesis in param list");
Expression::Parameters result;
while (it != end) {
if (!consumeToken(")").empty()) {
return result;
}
auto expr = parseExpression();
if (!expr) throw std::runtime_error("Expected expression in call args");
if (auto ident = dynamic_cast<VariableExpr*>(expr.get())) {
if (!consumeToken("=").empty()) {
auto value = parseExpression();
if (!value) throw std::runtime_error("Expected expression in for named arg");
result.emplace_back(ident->get_name(), std::move(value));
} else {
result.emplace_back(ident->get_name(), nullptr);
}
} else {
result.emplace_back(std::string(), std::move(expr));
}
if (consumeToken(",").empty()) {
if (consumeToken(")").empty()) {
throw std::runtime_error("Expected closing parenthesis in call args");
}
return result;
}
}
throw std::runtime_error("Expected closing parenthesis in call args");
}
ArgumentsExpression parseCallArgs() {
consumeSpaces();
if (consumeToken("(").empty()) throw std::runtime_error("Expected opening parenthesis in call args");
ArgumentsExpression result;
while (it != end) {
if (!consumeToken(")").empty()) {
return result;
}
auto expr = parseExpression();
if (!expr) throw std::runtime_error("Expected expression in call args");
if (auto ident = dynamic_cast<VariableExpr*>(expr.get())) {
if (!consumeToken("=").empty()) {
auto value = parseExpression();
if (!value) throw std::runtime_error("Expected expression in for named arg");
result.kwargs.emplace_back(ident->get_name(), std::move(value));
} else {
result.args.emplace_back(std::move(expr));
}
} else {
result.args.emplace_back(std::move(expr));
}
if (consumeToken(",").empty()) {
if (consumeToken(")").empty()) {
throw std::runtime_error("Expected closing parenthesis in call args");
}
return result;
}
}
throw std::runtime_error("Expected closing parenthesis in call args");
}
std::shared_ptr<VariableExpr> parseIdentifier() {
static std::regex ident_regex(R"((?!(?:not|is|and|or|del)\b)[a-zA-Z_]\w*)");
auto location = get_location();
auto ident = consumeToken(ident_regex);
if (ident.empty())
return nullptr;
return std::make_shared<VariableExpr>(location, ident);
}
std::shared_ptr<Expression> parseStringConcat() {
auto left = parseMathPow();
if (!left) throw std::runtime_error("Expected left side of 'string concat' expression");
static std::regex concat_tok(R"(~(?!\}))");
if (!consumeToken(concat_tok).empty()) {
auto right = parseLogicalAnd();
if (!right) throw std::runtime_error("Expected right side of 'string concat' expression");
left = std::make_shared<BinaryOpExpr>(get_location(), std::move(left), std::move(right), BinaryOpExpr::Op::StrConcat);
}
return left;
}
std::shared_ptr<Expression> parseMathPow() {
auto left = parseMathPlusMinus();
if (!left) throw std::runtime_error("Expected left side of 'math pow' expression");
while (!consumeToken("**").empty()) {
auto right = parseMathPlusMinus();
if (!right) throw std::runtime_error("Expected right side of 'math pow' expression");
left = std::make_shared<BinaryOpExpr>(get_location(), std::move(left), std::move(right), BinaryOpExpr::Op::MulMul);
}
return left;
}
std::shared_ptr<Expression> parseMathPlusMinus() {
static std::regex plus_minus_tok(R"(\+|-(?![}%#]\}))");
auto left = parseMathMulDiv();
if (!left) throw std::runtime_error("Expected left side of 'math plus/minus' expression");
std::string op_str;
while (!(op_str = consumeToken(plus_minus_tok)).empty()) {
auto right = parseMathMulDiv();
if (!right) throw std::runtime_error("Expected right side of 'math plus/minus' expression");
auto op = op_str == "+" ? BinaryOpExpr::Op::Add : BinaryOpExpr::Op::Sub;
left = std::make_shared<BinaryOpExpr>(get_location(), std::move(left), std::move(right), op);
}
return left;
}
std::shared_ptr<Expression> parseMathMulDiv() {
auto left = parseMathUnaryPlusMinus();
if (!left) throw std::runtime_error("Expected left side of 'math mul/div' expression");
static std::regex mul_div_tok(R"(\*\*?|//?|%(?!\}))");
std::string op_str;
while (!(op_str = consumeToken(mul_div_tok)).empty()) {
auto right = parseMathUnaryPlusMinus();
if (!right) throw std::runtime_error("Expected right side of 'math mul/div' expression");
auto op = op_str == "*" ? BinaryOpExpr::Op::Mul
: op_str == "**" ? BinaryOpExpr::Op::MulMul
: op_str == "/" ? BinaryOpExpr::Op::Div
: op_str == "//" ? BinaryOpExpr::Op::DivDiv
: BinaryOpExpr::Op::Mod;
left = std::make_shared<BinaryOpExpr>(get_location(), std::move(left), std::move(right), op);
}
if (!consumeToken("|").empty()) {
auto expr = parseMathMulDiv();
if (auto filter = dynamic_cast<FilterExpr*>(expr.get())) {
filter->prepend(std::move(left));
return expr;
} else {
std::vector<std::shared_ptr<Expression>> parts;
parts.emplace_back(std::move(left));
parts.emplace_back(std::move(expr));
return std::make_shared<FilterExpr>(get_location(), std::move(parts));
}
}
return left;
}
std::shared_ptr<Expression> call_func(const std::string & name, ArgumentsExpression && args) const {
return std::make_shared<CallExpr>(get_location(), std::make_shared<VariableExpr>(get_location(), name), std::move(args));
}
std::shared_ptr<Expression> parseMathUnaryPlusMinus() {
static std::regex unary_plus_minus_tok(R"(\+|-(?![}%#]\}))");
auto op_str = consumeToken(unary_plus_minus_tok);
auto expr = parseExpansion();
if (!expr) throw std::runtime_error("Expected expr of 'unary plus/minus/expansion' expression");
if (!op_str.empty()) {
auto op = op_str == "+" ? UnaryOpExpr::Op::Plus : UnaryOpExpr::Op::Minus;
return std::make_shared<UnaryOpExpr>(get_location(), std::move(expr), op);
}
return expr;
}
std::shared_ptr<Expression> parseExpansion() {
static std::regex expansion_tok(R"(\*\*?)");
auto op_str = consumeToken(expansion_tok);
auto expr = parseValueExpression();
if (op_str.empty()) return expr;
if (!expr) throw std::runtime_error("Expected expr of 'expansion' expression");
return std::make_shared<UnaryOpExpr>(get_location(), std::move(expr), op_str == "*" ? UnaryOpExpr::Op::Expansion : UnaryOpExpr::Op::ExpansionDict);
}
std::shared_ptr<Expression> parseValueExpression() {
auto parseValue = [&]() -> std::shared_ptr<Expression> {
auto location = get_location();
auto constant = parseConstant();
if (constant) return std::make_shared<LiteralExpr>(location, *constant);
static std::regex null_regex(R"(null\b)");
if (!consumeToken(null_regex).empty()) return std::make_shared<LiteralExpr>(location, Value());
auto identifier = parseIdentifier();
if (identifier) return identifier;
auto braced = parseBracedExpressionOrArray();
if (braced) return braced;
auto array = parseArray();
if (array) return array;
auto dictionary = parseDictionary();
if (dictionary) return dictionary;
throw std::runtime_error("Expected value expression");
};
auto value = parseValue();
while (it != end && consumeSpaces() && peekSymbols({ "[", "." })) {
if (!consumeToken("[").empty()) {
std::shared_ptr<Expression> index;
if (!consumeToken(":").empty()) {
auto slice_end = parseExpression();
index = std::make_shared<SliceExpr>(slice_end->location, nullptr, std::move(slice_end));
} else {
auto slice_start = parseExpression();
if (!consumeToken(":").empty()) {
consumeSpaces();
if (peekSymbols({ "]" })) {
index = std::make_shared<SliceExpr>(slice_start->location, std::move(slice_start), nullptr);
} else {
auto slice_end = parseExpression();
index = std::make_shared<SliceExpr>(slice_start->location, std::move(slice_start), std::move(slice_end));
}
} else {
index = std::move(slice_start);
}
}
if (!index) throw std::runtime_error("Empty index in subscript");
if (consumeToken("]").empty()) throw std::runtime_error("Expected closing bracket in subscript");
value = std::make_shared<SubscriptExpr>(value->location, std::move(value), std::move(index));
} else if (!consumeToken(".").empty()) {
auto identifier = parseIdentifier();
if (!identifier) throw std::runtime_error("Expected identifier in subscript");
consumeSpaces();
if (peekSymbols({ "(" })) {
auto callParams = parseCallArgs();
value = std::make_shared<MethodCallExpr>(identifier->location, std::move(value), std::move(identifier), std::move(callParams));
} else {
auto key = std::make_shared<LiteralExpr>(identifier->location, Value(identifier->get_name()));
value = std::make_shared<SubscriptExpr>(identifier->location, std::move(value), std::move(key));
}
}
consumeSpaces();
}
if (peekSymbols({ "(" })) {
auto location = get_location();
auto callParams = parseCallArgs();
value = std::make_shared<CallExpr>(location, std::move(value), std::move(callParams));
}
return value;
}
std::shared_ptr<Expression> parseBracedExpressionOrArray() {
if (consumeToken("(").empty()) return nullptr;
auto expr = parseExpression();
if (!expr) throw std::runtime_error("Expected expression in braced expression");
if (!consumeToken(")").empty()) {
return expr; // Drop the parentheses
}
std::vector<std::shared_ptr<Expression>> tuple;
tuple.emplace_back(std::move(expr));
while (it != end) {
if (consumeToken(",").empty()) throw std::runtime_error("Expected comma in tuple");
auto next = parseExpression();
if (!next) throw std::runtime_error("Expected expression in tuple");
tuple.push_back(std::move(next));
if (!consumeToken(")").empty()) {
return std::make_shared<ArrayExpr>(get_location(), std::move(tuple));
}
}
throw std::runtime_error("Expected closing parenthesis");
}
std::shared_ptr<Expression> parseArray() {
if (consumeToken("[").empty()) return nullptr;
std::vector<std::shared_ptr<Expression>> elements;
if (!consumeToken("]").empty()) {
return std::make_shared<ArrayExpr>(get_location(), std::move(elements));
}
auto first_expr = parseExpression();
if (!first_expr) throw std::runtime_error("Expected first expression in array");
elements.push_back(std::move(first_expr));
while (it != end) {
if (!consumeToken(",").empty()) {
auto expr = parseExpression();
if (!expr) throw std::runtime_error("Expected expression in array");
elements.push_back(std::move(expr));
} else if (!consumeToken("]").empty()) {
return std::make_shared<ArrayExpr>(get_location(), std::move(elements));
} else {
throw std::runtime_error("Expected comma or closing bracket in array");
}
}
throw std::runtime_error("Expected closing bracket");
}
std::shared_ptr<Expression> parseDictionary() {
if (consumeToken("{").empty()) return nullptr;
std::vector<std::pair<std::shared_ptr<Expression>, std::shared_ptr<Expression>>> elements;
if (!consumeToken("}").empty()) {
return std::make_shared<DictExpr>(get_location(), std::move(elements));
}
auto parseKeyValuePair = [&]() {
auto key = parseExpression();
if (!key) throw std::runtime_error("Expected key in dictionary");
if (consumeToken(":").empty()) throw std::runtime_error("Expected colon betweek key & value in dictionary");
auto value = parseExpression();
if (!value) throw std::runtime_error("Expected value in dictionary");
elements.emplace_back(std::pair(std::move(key), std::move(value)));
};
parseKeyValuePair();
while (it != end) {
if (!consumeToken(",").empty()) {
parseKeyValuePair();
} else if (!consumeToken("}").empty()) {
return std::make_shared<DictExpr>(get_location(), std::move(elements));
} else {
throw std::runtime_error("Expected comma or closing brace in dictionary");
}
}
throw std::runtime_error("Expected closing brace");
}
SpaceHandling parsePreSpace(const std::string& s) const {
if (s == "-")
return SpaceHandling::Strip;
return SpaceHandling::Keep;
}
SpaceHandling parsePostSpace(const std::string& s) const {
if (s == "-") return SpaceHandling::Strip;
return SpaceHandling::Keep;
}
using TemplateTokenVector = std::vector<std::unique_ptr<TemplateToken>>;
using TemplateTokenIterator = TemplateTokenVector::const_iterator;
std::vector<std::string> parseVarNames() {
static std::regex varnames_regex(R"(((?:\w+)(?:[\r\n\s]*,[\r\n\s]*(?:\w+))*)[\r\n\s]*)");
std::vector<std::string> group;
if ((group = consumeTokenGroups(varnames_regex)).empty()) throw std::runtime_error("Expected variable names");
std::vector<std::string> varnames;
std::istringstream iss(group[1]);
std::string varname;
while (std::getline(iss, varname, ',')) {
varnames.push_back(strip(varname));
}
return varnames;
}
std::runtime_error unexpected(const TemplateToken & token) const {
return std::runtime_error("Unexpected " + TemplateToken::typeToString(token.type)
+ error_location_suffix(*template_str, token.location.pos));
}
std::runtime_error unterminated(const TemplateToken & token) const {
return std::runtime_error("Unterminated " + TemplateToken::typeToString(token.type)
+ error_location_suffix(*template_str, token.location.pos));
}
TemplateTokenVector tokenize() {
static std::regex comment_tok(R"(\{#([-~]?)([\s\S\r\n]*?)([-~]?)#\})");
static std::regex expr_open_regex(R"(\{\{([-~])?)");
static std::regex block_open_regex(R"(^\{%([-~])?[\s\n\r]*)");
static std::regex block_keyword_tok(R"((if|else|elif|endif|for|endfor|generation|endgeneration|set|endset|block|endblock|macro|endmacro|filter|endfilter|break|continue)\b)");
static std::regex non_text_open_regex(R"(\{\{|\{%|\{#)");
static std::regex expr_close_regex(R"([\s\n\r]*([-~])?\}\})");
static std::regex block_close_regex(R"([\s\n\r]*([-~])?%\})");
TemplateTokenVector tokens;
std::vector<std::string> group;
std::string text;
std::smatch match;
try {
while (it != end) {
auto location = get_location();
if (!(group = consumeTokenGroups(comment_tok, SpaceHandling::Keep)).empty()) {
auto pre_space = parsePreSpace(group[1]);
auto content = group[2];
auto post_space = parsePostSpace(group[3]);
tokens.push_back(std::make_unique<CommentTemplateToken>(location, pre_space, post_space, content));
} else if (!(group = consumeTokenGroups(expr_open_regex, SpaceHandling::Keep)).empty()) {
auto pre_space = parsePreSpace(group[1]);
auto expr = parseExpression();
if ((group = consumeTokenGroups(expr_close_regex)).empty()) {
throw std::runtime_error("Expected closing expression tag");
}
auto post_space = parsePostSpace(group[1]);
tokens.push_back(std::make_unique<ExpressionTemplateToken>(location, pre_space, post_space, std::move(expr)));
} else if (!(group = consumeTokenGroups(block_open_regex, SpaceHandling::Keep)).empty()) {
auto pre_space = parsePreSpace(group[1]);
std::string keyword;
auto parseBlockClose = [&]() -> SpaceHandling {
if ((group = consumeTokenGroups(block_close_regex)).empty()) throw std::runtime_error("Expected closing block tag");
return parsePostSpace(group[1]);
};
if ((keyword = consumeToken(block_keyword_tok)).empty()) throw std::runtime_error("Expected block keyword");
if (keyword == "if") {
auto condition = parseExpression();
if (!condition) throw std::runtime_error("Expected condition in if block");
auto post_space = parseBlockClose();
tokens.push_back(std::make_unique<IfTemplateToken>(location, pre_space, post_space, std::move(condition)));
} else if (keyword == "elif") {
auto condition = parseExpression();
if (!condition) throw std::runtime_error("Expected condition in elif block");
auto post_space = parseBlockClose();
tokens.push_back(std::make_unique<ElifTemplateToken>(location, pre_space, post_space, std::move(condition)));
} else if (keyword == "else") {
auto post_space = parseBlockClose();
tokens.push_back(std::make_unique<ElseTemplateToken>(location, pre_space, post_space));
} else if (keyword == "endif") {
auto post_space = parseBlockClose();
tokens.push_back(std::make_unique<EndIfTemplateToken>(location, pre_space, post_space));
} else if (keyword == "for") {
static std::regex recursive_tok(R"(recursive\b)");
static std::regex if_tok(R"(if\b)");
auto varnames = parseVarNames();
static std::regex in_tok(R"(in\b)");
if (consumeToken(in_tok).empty()) throw std::runtime_error("Expected 'in' keyword in for block");
auto iterable = parseExpression(/* allow_if_expr = */ false);
if (!iterable) throw std::runtime_error("Expected iterable in for block");
std::shared_ptr<Expression> condition;
if (!consumeToken(if_tok).empty()) {
condition = parseExpression();
}
auto recursive = !consumeToken(recursive_tok).empty();
auto post_space = parseBlockClose();
tokens.push_back(std::make_unique<ForTemplateToken>(location, pre_space, post_space, std::move(varnames), std::move(iterable), std::move(condition), recursive));
} else if (keyword == "endfor") {
auto post_space = parseBlockClose();
tokens.push_back(std::make_unique<EndForTemplateToken>(location, pre_space, post_space));
} else if (keyword == "generation") {
auto post_space = parseBlockClose();
tokens.push_back(std::make_unique<GenerationTemplateToken>(location, pre_space, post_space));
} else if (keyword == "endgeneration") {
auto post_space = parseBlockClose();
tokens.push_back(std::make_unique<EndGenerationTemplateToken>(location, pre_space, post_space));
} else if (keyword == "set") {
static std::regex namespaced_var_regex(R"((\w+)[\s\n\r]*\.[\s\n\r]*(\w+))");
std::string ns;
std::vector<std::string> var_names;
std::shared_ptr<Expression> value;
if (!(group = consumeTokenGroups(namespaced_var_regex)).empty()) {
ns = group[1];
var_names.push_back(group[2]);
if (consumeToken("=").empty()) throw std::runtime_error("Expected equals sign in set block");
value = parseExpression();
if (!value) throw std::runtime_error("Expected value in set block");
} else {
var_names = parseVarNames();
if (!consumeToken("=").empty()) {
value = parseExpression();
if (!value) throw std::runtime_error("Expected value in set block");
}
}
auto post_space = parseBlockClose();
tokens.push_back(std::make_unique<SetTemplateToken>(location, pre_space, post_space, ns, var_names, std::move(value)));
} else if (keyword == "endset") {
auto post_space = parseBlockClose();
tokens.push_back(std::make_unique<EndSetTemplateToken>(location, pre_space, post_space));
} else if (keyword == "macro") {
auto macroname = parseIdentifier();
if (!macroname) throw std::runtime_error("Expected macro name in macro block");
auto params = parseParameters();
auto post_space = parseBlockClose();
tokens.push_back(std::make_unique<MacroTemplateToken>(location, pre_space, post_space, std::move(macroname), std::move(params)));
} else if (keyword == "endmacro") {
auto post_space = parseBlockClose();
tokens.push_back(std::make_unique<EndMacroTemplateToken>(location, pre_space, post_space));
} else if (keyword == "filter") {
auto filter = parseExpression();
if (!filter) throw std::runtime_error("Expected expression in filter block");
auto post_space = parseBlockClose();
tokens.push_back(std::make_unique<FilterTemplateToken>(location, pre_space, post_space, std::move(filter)));
} else if (keyword == "endfilter") {
auto post_space = parseBlockClose();
tokens.push_back(std::make_unique<EndFilterTemplateToken>(location, pre_space, post_space));
} else if (keyword == "break" || keyword == "continue") {
auto post_space = parseBlockClose();
tokens.push_back(std::make_unique<LoopControlTemplateToken>(location, pre_space, post_space, keyword == "break" ? LoopControlType::Break : LoopControlType::Continue));
} else {
throw std::runtime_error("Unexpected block: " + keyword);
}
} else if (std::regex_search(it, end, match, non_text_open_regex)) {
auto text_end = it + match.position();
text = std::string(it, text_end);
it = text_end;
tokens.push_back(std::make_unique<TextTemplateToken>(location, SpaceHandling::Keep, SpaceHandling::Keep, text));
} else {
text = std::string(it, end);
it = end;
tokens.push_back(std::make_unique<TextTemplateToken>(location, SpaceHandling::Keep, SpaceHandling::Keep, text));
}
}
return tokens;
} catch (const std::exception & e) {
throw std::runtime_error(e.what() + error_location_suffix(*template_str, std::distance(start, it)));
}
}
std::shared_ptr<TemplateNode> parseTemplate(
const TemplateTokenIterator & begin,
TemplateTokenIterator & it,
const TemplateTokenIterator & end,
bool fully = false) const {
std::vector<std::shared_ptr<TemplateNode>> children;
while (it != end) {
const auto start = it;
const auto & token = *(it++);
if (auto if_token = dynamic_cast<IfTemplateToken*>(token.get())) {
std::vector<std::pair<std::shared_ptr<Expression>, std::shared_ptr<TemplateNode>>> cascade;
cascade.emplace_back(std::move(if_token->condition), parseTemplate(begin, it, end));
while (it != end && (*it)->type == TemplateToken::Type::Elif) {
auto elif_token = dynamic_cast<ElifTemplateToken*>((*(it++)).get());
cascade.emplace_back(std::move(elif_token->condition), parseTemplate(begin, it, end));
}
if (it != end && (*it)->type == TemplateToken::Type::Else) {
cascade.emplace_back(nullptr, parseTemplate(begin, ++it, end));
}
if (it == end || (*(it++))->type != TemplateToken::Type::EndIf) {
throw unterminated(**start);
}
children.emplace_back(std::make_shared<IfNode>(token->location, std::move(cascade)));
} else if (auto for_token = dynamic_cast<ForTemplateToken*>(token.get())) {
auto body = parseTemplate(begin, it, end);
auto else_body = std::shared_ptr<TemplateNode>();
if (it != end && (*it)->type == TemplateToken::Type::Else) {
else_body = parseTemplate(begin, ++it, end);
}
if (it == end || (*(it++))->type != TemplateToken::Type::EndFor) {
throw unterminated(**start);
}
children.emplace_back(std::make_shared<ForNode>(token->location, std::move(for_token->var_names), std::move(for_token->iterable), std::move(for_token->condition), std::move(body), for_token->recursive, std::move(else_body)));
} else if (dynamic_cast<GenerationTemplateToken*>(token.get())) {
auto body = parseTemplate(begin, it, end);
if (it == end || (*(it++))->type != TemplateToken::Type::EndGeneration) {
throw unterminated(**start);
}
// Treat as a no-op, as our scope is templates for inference, not training (`{% generation %}` wraps generated tokens for masking).
children.emplace_back(std::move(body));
} else if (auto text_token = dynamic_cast<TextTemplateToken*>(token.get())) {
SpaceHandling pre_space = (it - 1) != begin ? (*(it - 2))->post_space : SpaceHandling::Keep;
SpaceHandling post_space = it != end ? (*it)->pre_space : SpaceHandling::Keep;
auto text = text_token->text;
if (post_space == SpaceHandling::Strip) {
static std::regex trailing_space_regex(R"((\s|\r|\n)+$)");
text = std::regex_replace(text, trailing_space_regex, "");
} else if (options.lstrip_blocks && it != end) {
auto i = text.size();
while (i > 0 && (text[i - 1] == ' ' || text[i - 1] == '\t')) i--;
if ((i == 0 && (it - 1) == begin) || (i > 0 && text[i - 1] == '\n')) {
text.resize(i);
}
}
if (pre_space == SpaceHandling::Strip) {
static std::regex leading_space_regex(R"(^(\s|\r|\n)+)");
text = std::regex_replace(text, leading_space_regex, "");
} else if (options.trim_blocks && (it - 1) != begin && !dynamic_cast<ExpressionTemplateToken*>((*(it - 2)).get())) {
if (text.length() > 0 && text[0] == '\n') {
text.erase(0, 1);
}
}
if (it == end && !options.keep_trailing_newline) {
auto i = text.size();
if (i > 0 && text[i - 1] == '\n') {
i--;
if (i > 0 && text[i - 1] == '\r') i--;
text.resize(i);
}
}
children.emplace_back(std::make_shared<TextNode>(token->location, text));
} else if (auto expr_token = dynamic_cast<ExpressionTemplateToken*>(token.get())) {
children.emplace_back(std::make_shared<ExpressionNode>(token->location, std::move(expr_token->expr)));
} else if (auto set_token = dynamic_cast<SetTemplateToken*>(token.get())) {
if (set_token->value) {
children.emplace_back(std::make_shared<SetNode>(token->location, set_token->ns, set_token->var_names, std::move(set_token->value)));
} else {
auto value_template = parseTemplate(begin, it, end);
if (it == end || (*(it++))->type != TemplateToken::Type::EndSet) {
throw unterminated(**start);
}
if (!set_token->ns.empty()) throw std::runtime_error("Namespaced set not supported in set with template value");
if (set_token->var_names.size() != 1) throw std::runtime_error("Structural assignment not supported in set with template value");
auto & name = set_token->var_names[0];
children.emplace_back(std::make_shared<SetTemplateNode>(token->location, name, std::move(value_template)));
}
} else if (auto macro_token = dynamic_cast<MacroTemplateToken*>(token.get())) {
auto body = parseTemplate(begin, it, end);
if (it == end || (*(it++))->type != TemplateToken::Type::EndMacro) {
throw unterminated(**start);
}
children.emplace_back(std::make_shared<MacroNode>(token->location, std::move(macro_token->name), std::move(macro_token->params), std::move(body)));
} else if (auto filter_token = dynamic_cast<FilterTemplateToken*>(token.get())) {
auto body = parseTemplate(begin, it, end);
if (it == end || (*(it++))->type != TemplateToken::Type::EndFilter) {
throw unterminated(**start);
}
children.emplace_back(std::make_shared<FilterNode>(token->location, std::move(filter_token->filter), std::move(body)));
} else if (dynamic_cast<CommentTemplateToken*>(token.get())) {
// Ignore comments
} else if (auto ctrl_token = dynamic_cast<LoopControlTemplateToken*>(token.get())) {
children.emplace_back(std::make_shared<LoopControlNode>(token->location, ctrl_token->control_type));
} else if (dynamic_cast<EndForTemplateToken*>(token.get())
|| dynamic_cast<EndSetTemplateToken*>(token.get())
|| dynamic_cast<EndMacroTemplateToken*>(token.get())
|| dynamic_cast<EndFilterTemplateToken*>(token.get())
|| dynamic_cast<EndIfTemplateToken*>(token.get())
|| dynamic_cast<ElseTemplateToken*>(token.get())
|| dynamic_cast<EndGenerationTemplateToken*>(token.get())
|| dynamic_cast<ElifTemplateToken*>(token.get())) {
it--; // unconsume the token
break; // exit the loop
} else {
throw unexpected(**(it-1));
}
}
if (fully && it != end) {
throw unexpected(**it);
}
if (children.empty()) {
return std::make_shared<TextNode>(Location { template_str, 0 }, std::string());
} else if (children.size() == 1) {
return std::move(children[0]);
} else {
return std::make_shared<SequenceNode>(children[0]->location(), std::move(children));
}
}
public:
static std::shared_ptr<TemplateNode> parse(const std::string& template_str, const Options & options) {
Parser parser(std::make_shared<std::string>(normalize_newlines(template_str)), options);
auto tokens = parser.tokenize();
TemplateTokenIterator begin = tokens.begin();
auto it = begin;
TemplateTokenIterator end = tokens.end();
return parser.parseTemplate(begin, it, end, /* full= */ true);
}
};
static Value simple_function(const std::string & fn_name, const std::vector<std::string> & params, const std::function<Value(const std::shared_ptr<Context> &, Value & args)> & fn) {
std::map<std::string, size_t> named_positions;
for (size_t i = 0, n = params.size(); i < n; i++) named_positions[params[i]] = i;
return Value::callable([=](const std::shared_ptr<Context> & context, ArgumentsValue & args) -> Value {
auto args_obj = Value::object();
std::vector<bool> provided_args(params.size());
for (size_t i = 0, n = args.args.size(); i < n; i++) {
auto & arg = args.args[i];
if (i < params.size()) {
args_obj.set(params[i], arg);
provided_args[i] = true;
} else {
throw std::runtime_error("Too many positional params for " + fn_name);
}
}
for (auto & [name, value] : args.kwargs) {
auto named_pos_it = named_positions.find(name);
if (named_pos_it == named_positions.end()) {
throw std::runtime_error("Unknown argument " + name + " for function " + fn_name);
}
provided_args[named_pos_it->second] = true;
args_obj.set(name, value);
}
return fn(context, args_obj);
});
}
inline std::shared_ptr<Context> Context::builtins() {
auto globals = Value::object();
globals.set("raise_exception", simple_function("raise_exception", { "message" }, [](const std::shared_ptr<Context> &, Value & args) -> Value {
throw std::runtime_error(args.at("message").get<std::string>());
}));
globals.set("tojson", simple_function("tojson", { "value", "indent" }, [](const std::shared_ptr<Context> &, Value & args) {
return Value(args.at("value").dump(args.get<int64_t>("indent", -1), /* tojson= */ true));
}));
globals.set("items", simple_function("items", { "object" }, [](const std::shared_ptr<Context> &, Value & args) {
auto items = Value::array();
if (args.contains("object")) {
auto & obj = args.at("object");
if (obj.is_string()) {
auto json_obj = json::parse(obj.get<std::string>());
for (const auto & kv : json_obj.items()) {
items.push_back(Value::array({kv.key(), kv.value()}));
}
} else if (!obj.is_null()) {
for (auto & key : obj.keys()) {
items.push_back(Value::array({key, obj.at(key)}));
}
}
}
return items;
}));
globals.set("last", simple_function("last", { "items" }, [](const std::shared_ptr<Context> &, Value & args) {
auto items = args.at("items");
if (!items.is_array()) throw std::runtime_error("object is not a list");
if (items.size() == 0) return Value();
return items.at(items.size() - 1);
}));
globals.set("trim", simple_function("trim", { "text" }, [](const std::shared_ptr<Context> &, Value & args) {
auto & text = args.at("text");
return text.is_null() ? text : Value(strip(text.get<std::string>()));
}));
globals.set("lower", simple_function("lower", { "text" }, [](const std::shared_ptr<Context> &, Value & args) {
auto text = args.at("text");
if (text.is_null()) return text;
std::string res;
auto str = text.get<std::string>();
std::transform(str.begin(), str.end(), std::back_inserter(res), ::tolower);
return Value(res);
}));
globals.set("default", Value::callable([=](const std::shared_ptr<Context> &, ArgumentsValue & args) {
args.expectArgs("default", {2, 3}, {0, 1});
auto & value = args.args[0];
auto & default_value = args.args[1];
bool boolean = false;
if (args.args.size() == 3) {
boolean = args.args[2].get<bool>();
} else {
Value bv = args.get_named("boolean");
if (!bv.is_null()) {
boolean = bv.get<bool>();
}
}
return boolean ? (value.to_bool() ? value : default_value) : value.is_null() ? default_value : value;
}));
auto escape = simple_function("escape", { "text" }, [](const std::shared_ptr<Context> &, Value & args) {
return Value(html_escape(args.at("text").get<std::string>()));
});
globals.set("e", escape);
globals.set("escape", escape);
globals.set("joiner", simple_function("joiner", { "sep" }, [](const std::shared_ptr<Context> &, Value & args) {
auto sep = args.get<std::string>("sep", "");
auto first = std::make_shared<bool>(true);
return simple_function("", {}, [sep, first](const std::shared_ptr<Context> &, const Value &) -> Value {
if (*first) {
*first = false;
return "";
}
return sep;
});
return Value(html_escape(args.at("text").get<std::string>()));
}));
globals.set("count", simple_function("count", { "items" }, [](const std::shared_ptr<Context> &, Value & args) {
return Value((int64_t) args.at("items").size());
}));
globals.set("dictsort", simple_function("dictsort", { "value" }, [](const std::shared_ptr<Context> &, Value & args) {
if (args.size() != 1) throw std::runtime_error("dictsort expects exactly 1 argument (TODO: fix implementation)");
auto & value = args.at("value");
auto keys = value.keys();
std::sort(keys.begin(), keys.end());
auto res = Value::array();
for (auto & key : keys) {
res.push_back(Value::array({key, value.at(key)}));
}
return res;
}));
globals.set("join", simple_function("join", { "items", "d" }, [](const std::shared_ptr<Context> &, Value & args) {
auto do_join = [](Value & items, const std::string & sep) {
if (!items.is_array()) throw std::runtime_error("object is not iterable: " + items.dump());
std::ostringstream oss;
auto first = true;
for (size_t i = 0, n = items.size(); i < n; ++i) {
if (first) first = false;
else oss << sep;
oss << items.at(i).to_str();
}
return Value(oss.str());
};
auto sep = args.get<std::string>("d", "");
if (args.contains("items")) {
auto & items = args.at("items");
return do_join(items, sep);
} else {
return simple_function("", {"items"}, [sep, do_join](const std::shared_ptr<Context> &, Value & args) {
auto & items = args.at("items");
if (!items.to_bool() || !items.is_array()) throw std::runtime_error("join expects an array for items, got: " + items.dump());
return do_join(items, sep);
});
}
}));
globals.set("namespace", Value::callable([=](const std::shared_ptr<Context> &, ArgumentsValue & args) {
auto ns = Value::object();
args.expectArgs("namespace", {0, 0}, {0, (std::numeric_limits<size_t>::max)()});
for (auto & [name, value] : args.kwargs) {
ns.set(name, value);
}
return ns;
}));
auto equalto = simple_function("equalto", { "expected", "actual" }, [](const std::shared_ptr<Context> &, Value & args) -> Value {
return args.at("actual") == args.at("expected");
});
globals.set("equalto", equalto);
globals.set("==", equalto);
globals.set("length", simple_function("length", { "items" }, [](const std::shared_ptr<Context> &, Value & args) -> Value {
auto & items = args.at("items");
return (int64_t) items.size();
}));
globals.set("safe", simple_function("safe", { "value" }, [](const std::shared_ptr<Context> &, Value & args) -> Value {
return args.at("value").to_str();
}));
globals.set("string", simple_function("string", { "value" }, [](const std::shared_ptr<Context> &, Value & args) -> Value {
return args.at("value").to_str();
}));
globals.set("int", simple_function("int", { "value" }, [](const std::shared_ptr<Context> &, Value & args) -> Value {
return args.at("value").to_int();
}));
globals.set("list", simple_function("list", { "items" }, [](const std::shared_ptr<Context> &, Value & args) -> Value {
auto & items = args.at("items");
if (!items.is_array()) throw std::runtime_error("object is not iterable");
return items;
}));
globals.set("unique", simple_function("unique", { "items" }, [](const std::shared_ptr<Context> &, Value & args) -> Value {
auto & items = args.at("items");
if (!items.is_array()) throw std::runtime_error("object is not iterable");
std::unordered_set<Value> seen;
auto result = Value::array();
for (size_t i = 0, n = items.size(); i < n; i++) {
auto pair = seen.insert(items.at(i));
if (pair.second) {
result.push_back(items.at(i));
}
}
return result;
}));
auto make_filter = [](const Value & filter, Value & extra_args) -> Value {
return simple_function("", { "value" }, [=](const std::shared_ptr<Context> & context, Value & args) {
auto & value = args.at("value");
ArgumentsValue actual_args;
actual_args.args.emplace_back(value);
for (size_t i = 0, n = extra_args.size(); i < n; i++) {
actual_args.args.emplace_back(extra_args.at(i));
}
return filter.call(context, actual_args);
});
};
auto select_or_reject = [make_filter](bool is_select) {
return Value::callable([=](const std::shared_ptr<Context> & context, ArgumentsValue & args) {
args.expectArgs(is_select ? "select" : "reject", {2, (std::numeric_limits<size_t>::max)()}, {0, 0});
auto & items = args.args[0];
if (items.is_null())
return Value::array();
if (!items.is_array()) throw std::runtime_error("object is not iterable: " + items.dump());
auto filter_fn = context->get(args.args[1]);
if (filter_fn.is_null()) throw std::runtime_error("Undefined filter: " + args.args[1].dump());
auto filter_args = Value::array();
for (size_t i = 2, n = args.args.size(); i < n; i++) {
filter_args.push_back(args.args[i]);
}
auto filter = make_filter(filter_fn, filter_args);
auto res = Value::array();
for (size_t i = 0, n = items.size(); i < n; i++) {
auto & item = items.at(i);
ArgumentsValue filter_args;
filter_args.args.emplace_back(item);
auto pred_res = filter.call(context, filter_args);
if (pred_res.to_bool() == (is_select ? true : false)) {
res.push_back(item);
}
}
return res;
});
};
globals.set("select", select_or_reject(/* is_select= */ true));
globals.set("reject", select_or_reject(/* is_select= */ false));
globals.set("map", Value::callable([=](const std::shared_ptr<Context> & context, ArgumentsValue & args) {
auto res = Value::array();
if (args.args.size() == 1 &&
((args.has_named("attribute") && args.kwargs.size() == 1) || (args.has_named("default") && args.kwargs.size() == 2))) {
auto & items = args.args[0];
auto attr_name = args.get_named("attribute");
auto default_value = args.get_named("default");
for (size_t i = 0, n = items.size(); i < n; i++) {
auto & item = items.at(i);
auto attr = item.get(attr_name);
res.push_back(attr.is_null() ? default_value : attr);
}
} else if (args.kwargs.empty() && args.args.size() >= 2) {
auto fn = context->get(args.args[1]);
if (fn.is_null()) throw std::runtime_error("Undefined filter: " + args.args[1].dump());
ArgumentsValue filter_args { {Value()}, {} };
for (size_t i = 2, n = args.args.size(); i < n; i++) {
filter_args.args.emplace_back(args.args[i]);
}
for (size_t i = 0, n = args.args[0].size(); i < n; i++) {
auto & item = args.args[0].at(i);
filter_args.args[0] = item;
res.push_back(fn.call(context, filter_args));
}
} else {
throw std::runtime_error("Invalid or unsupported arguments for map");
}
return res;
}));
globals.set("indent", simple_function("indent", { "text", "indent", "first" }, [](const std::shared_ptr<Context> &, Value & args) {
auto text = args.at("text").get<std::string>();
auto first = args.get<bool>("first", false);
std::string out;
std::string indent(args.get<int64_t>("indent", 0), ' ');
std::istringstream iss(text);
std::string line;
auto is_first = true;
while (std::getline(iss, line, '\n')) {
auto needs_indent = !is_first || first;
if (is_first) is_first = false;
else out += "\n";
if (needs_indent) out += indent;
out += line;
}
if (!text.empty() && text.back() == '\n') out += "\n";
return out;
}));
auto select_or_reject_attr = [](bool is_select) {
return Value::callable([=](const std::shared_ptr<Context> & context, ArgumentsValue & args) {
args.expectArgs(is_select ? "selectattr" : "rejectattr", {2, (std::numeric_limits<size_t>::max)()}, {0, 0});
auto & items = args.args[0];
if (items.is_null())
return Value::array();
if (!items.is_array()) throw std::runtime_error("object is not iterable: " + items.dump());
auto attr_name = args.args[1].get<std::string>();
bool has_test = false;
Value test_fn;
ArgumentsValue test_args {{Value()}, {}};
if (args.args.size() >= 3) {
has_test = true;
test_fn = context->get(args.args[2]);
if (test_fn.is_null()) throw std::runtime_error("Undefined test: " + args.args[2].dump());
for (size_t i = 3, n = args.args.size(); i < n; i++) {
test_args.args.emplace_back(args.args[i]);
}
test_args.kwargs = args.kwargs;
}
auto res = Value::array();
for (size_t i = 0, n = items.size(); i < n; i++) {
auto & item = items.at(i);
auto attr = item.get(attr_name);
if (has_test) {
test_args.args[0] = attr;
if (test_fn.call(context, test_args).to_bool() == (is_select ? true : false)) {
res.push_back(item);
}
} else {
res.push_back(attr);
}
}
return res;
});
};
globals.set("selectattr", select_or_reject_attr(/* is_select= */ true));
globals.set("rejectattr", select_or_reject_attr(/* is_select= */ false));
globals.set("range", Value::callable([=](const std::shared_ptr<Context> &, ArgumentsValue & args) {
std::vector<int64_t> startEndStep(3);
std::vector<bool> param_set(3);
if (args.args.size() == 1) {
startEndStep[1] = args.args[0].get<int64_t>();
param_set[1] = true;
} else {
for (size_t i = 0; i < args.args.size(); i++) {
auto & arg = args.args[i];
auto v = arg.get<int64_t>();
startEndStep[i] = v;
param_set[i] = true;
}
}
for (auto & [name, value] : args.kwargs) {
size_t i;
if (name == "start") i = 0;
else if (name == "end") i = 1;
else if (name == "step") i = 2;
else throw std::runtime_error("Unknown argument " + name + " for function range");
if (param_set[i]) {
throw std::runtime_error("Duplicate argument " + name + " for function range");
}
startEndStep[i] = value.get<int64_t>();
param_set[i] = true;
}
if (!param_set[1]) {
throw std::runtime_error("Missing required argument 'end' for function range");
}
int64_t start = param_set[0] ? startEndStep[0] : 0;
int64_t end = startEndStep[1];
int64_t step = param_set[2] ? startEndStep[2] : 1;
auto res = Value::array();
if (step > 0) {
for (int64_t i = start; i < end; i += step) {
res.push_back(Value(i));
}
} else {
for (int64_t i = start; i > end; i += step) {
res.push_back(Value(i));
}
}
return res;
}));
return std::make_shared<Context>(std::move(globals));
}
inline std::shared_ptr<Context> Context::make(Value && values, const std::shared_ptr<Context> & parent) {
return std::make_shared<Context>(values.is_null() ? Value::object() : std::move(values), parent);
}
} // namespace minja