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// Copyright (c) 2020 Pantor. All rights reserved.
#ifndef INCLUDE_INJA_PARSER_HPP_
#define INCLUDE_INJA_PARSER_HPP_
#include <limits>
#include <stack>
#include <string>
#include <utility>
#include <queue>
#include <vector>
#include "config.hpp"
#include "exceptions.hpp"
#include "function_storage.hpp"
#include "lexer.hpp"
#include "node.hpp"
#include "template.hpp"
#include "token.hpp"
#include "utils.hpp"
#include <nlohmann/json.hpp>
namespace inja {
/*!
* \brief Class for parsing an inja Template.
*/
class Parser {
const ParserConfig &config;
Lexer lexer;
TemplateStorage &template_storage;
const FunctionStorage &function_storage;
Token tok, peek_tok;
bool have_peek_tok {false};
size_t current_paren_level {0};
size_t current_bracket_level {0};
size_t current_brace_level {0};
nonstd::string_view json_literal_start;
BlockNode *current_block {nullptr};
ExpressionListNode *current_expression_list {nullptr};
std::stack<std::pair<FunctionNode*, size_t>> function_stack;
std::stack<std::shared_ptr<FunctionNode>> operator_stack;
std::stack<IfStatementNode*> if_statement_stack;
std::stack<ForStatementNode*> for_statement_stack;
void throw_parser_error(const std::string &message) {
throw ParserError(message, lexer.current_position());
}
void get_next_token() {
if (have_peek_tok) {
tok = peek_tok;
have_peek_tok = false;
} else {
tok = lexer.scan();
}
}
void get_peek_token() {
if (!have_peek_tok) {
peek_tok = lexer.scan();
have_peek_tok = true;
}
}
void add_json_literal(const char* content_ptr) {
nonstd::string_view json_text(json_literal_start.data(), tok.text.data() - json_literal_start.data() + tok.text.size());
current_expression_list->rpn_output.emplace_back(std::make_shared<LiteralNode>(json::parse(json_text), json_text.data() - content_ptr));
}
bool parse_expression(Template &tmpl, Token::Kind closing) {
while (tok.kind != closing && tok.kind != Token::Kind::Eof) {
// Literals
switch (tok.kind) {
case Token::Kind::String: {
if (current_brace_level == 0 && current_bracket_level == 0) {
json_literal_start = tok.text;
add_json_literal(tmpl.content.c_str());
}
} break;
case Token::Kind::Number: {
if (current_brace_level == 0 && current_bracket_level == 0) {
json_literal_start = tok.text;
add_json_literal(tmpl.content.c_str());
}
} break;
case Token::Kind::LeftBracket: {
if (current_brace_level == 0 && current_bracket_level == 0) {
json_literal_start = tok.text;
}
current_bracket_level += 1;
} break;
case Token::Kind::LeftBrace: {
if (current_brace_level == 0 && current_bracket_level == 0) {
json_literal_start = tok.text;
}
current_brace_level += 1;
} break;
case Token::Kind::RightBracket: {
if (current_bracket_level == 0) {
throw_parser_error("unexpected ']'");
}
current_bracket_level -= 1;
if (current_brace_level == 0 && current_bracket_level == 0) {
add_json_literal(tmpl.content.c_str());
}
} break;
case Token::Kind::RightBrace: {
if (current_brace_level == 0) {
throw_parser_error("unexpected '}'");
}
current_brace_level -= 1;
if (current_brace_level == 0 && current_bracket_level == 0) {
add_json_literal(tmpl.content.c_str());
}
} break;
case Token::Kind::Id: {
get_peek_token();
// Json Literal
if (tok.text == static_cast<decltype(tok.text)>("true") || tok.text == static_cast<decltype(tok.text)>("false") || tok.text == static_cast<decltype(tok.text)>("null")) {
if (current_brace_level == 0 && current_bracket_level == 0) {
json_literal_start = tok.text;
add_json_literal(tmpl.content.c_str());
}
// Operator
} else if (tok.text == "and" || tok.text == "or" || tok.text == "in" || tok.text == "not") {
goto parse_operator;
// Functions
} else if (peek_tok.kind == Token::Kind::LeftParen) {
operator_stack.emplace(std::make_shared<FunctionNode>(static_cast<std::string>(tok.text), tok.text.data() - tmpl.content.c_str()));
function_stack.emplace(operator_stack.top().get(), current_paren_level);
// Variables
} else {
current_expression_list->rpn_output.emplace_back(std::make_shared<JsonNode>(static_cast<std::string>(tok.text), tok.text.data() - tmpl.content.c_str()));
}
// Operators
} break;
case Token::Kind::Equal:
case Token::Kind::NotEqual:
case Token::Kind::GreaterThan:
case Token::Kind::GreaterEqual:
case Token::Kind::LessThan:
case Token::Kind::LessEqual:
case Token::Kind::Plus:
case Token::Kind::Minus:
case Token::Kind::Times:
case Token::Kind::Slash:
case Token::Kind::Power:
case Token::Kind::Percent:
case Token::Kind::Dot: {
parse_operator:
FunctionStorage::Operation operation;
switch (tok.kind) {
case Token::Kind::Id: {
if (tok.text == "and") {
operation = FunctionStorage::Operation::And;
} else if (tok.text == "or") {
operation = FunctionStorage::Operation::Or;
} else if (tok.text == "in") {
operation = FunctionStorage::Operation::In;
} else if (tok.text == "not") {
operation = FunctionStorage::Operation::Not;
} else {
throw_parser_error("unknown operator in parser.");
}
} break;
case Token::Kind::Equal: {
operation = FunctionStorage::Operation::Equal;
} break;
case Token::Kind::NotEqual: {
operation = FunctionStorage::Operation::NotEqual;
} break;
case Token::Kind::GreaterThan: {
operation = FunctionStorage::Operation::Greater;
} break;
case Token::Kind::GreaterEqual: {
operation = FunctionStorage::Operation::GreaterEqual;
} break;
case Token::Kind::LessThan: {
operation = FunctionStorage::Operation::Less;
} break;
case Token::Kind::LessEqual: {
operation = FunctionStorage::Operation::LessEqual;
} break;
case Token::Kind::Plus: {
operation = FunctionStorage::Operation::Add;
} break;
case Token::Kind::Minus: {
operation = FunctionStorage::Operation::Subtract;
} break;
case Token::Kind::Times: {
operation = FunctionStorage::Operation::Multiplication;
} break;
case Token::Kind::Slash: {
operation = FunctionStorage::Operation::Division;
} break;
case Token::Kind::Power: {
operation = FunctionStorage::Operation::Power;
} break;
case Token::Kind::Percent: {
operation = FunctionStorage::Operation::Modulo;
} break;
case Token::Kind::Dot: {
operation = FunctionStorage::Operation::AtId;
} break;
default: {
throw_parser_error("unknown operator in parser.");
}
}
auto function_node = std::make_shared<FunctionNode>(operation, tok.text.data() - tmpl.content.c_str());
while (!operator_stack.empty() && ((operator_stack.top()->precedence > function_node->precedence) || (operator_stack.top()->precedence == function_node->precedence && function_node->associativity == FunctionNode::Associativity::Left)) && (operator_stack.top()->operation != FunctionStorage::Operation::ParenLeft)) {
current_expression_list->rpn_output.emplace_back(operator_stack.top());
operator_stack.pop();
}
operator_stack.emplace(function_node);
} break;
case Token::Kind::Comma: {
if (current_brace_level == 0 && current_bracket_level == 0) {
if (function_stack.empty()) {
throw_parser_error("unexpected ','");
}
function_stack.top().first->number_args += 1;
}
} break;
case Token::Kind::Colon: {
if (current_brace_level == 0 && current_bracket_level == 0) {
throw_parser_error("unexpected ':'");
}
} break;
case Token::Kind::LeftParen: {
current_paren_level += 1;
operator_stack.emplace(std::make_shared<FunctionNode>(FunctionStorage::Operation::ParenLeft, tok.text.data() - tmpl.content.c_str()));
get_peek_token();
if (peek_tok.kind == Token::Kind::RightParen) {
if (!function_stack.empty() && function_stack.top().second == current_paren_level - 1) {
function_stack.top().first->number_args = 0;
}
}
} break;
case Token::Kind::RightParen: {
current_paren_level -= 1;
while (!operator_stack.empty() && operator_stack.top()->operation != FunctionStorage::Operation::ParenLeft) {
current_expression_list->rpn_output.emplace_back(operator_stack.top());
operator_stack.pop();
}
if (!operator_stack.empty() && operator_stack.top()->operation == FunctionStorage::Operation::ParenLeft) {
operator_stack.pop();
}
if (!function_stack.empty() && function_stack.top().second == current_paren_level) {
auto func = function_stack.top().first;
auto function_data = function_storage.find_function(func->name, func->number_args);
if (function_data.operation == FunctionStorage::Operation::None) {
throw_parser_error("unknown function " + func->name);
}
func->operation = function_data.operation;
if (function_data.operation == FunctionStorage::Operation::Callback) {
func->callback = function_data.callback;
}
if (operator_stack.empty()) {
throw_parser_error("internal error at function " + func->name);
}
current_expression_list->rpn_output.emplace_back(operator_stack.top());
operator_stack.pop();
function_stack.pop();
}
}
default:
break;
}
get_next_token();
}
while (!operator_stack.empty()) {
current_expression_list->rpn_output.emplace_back(operator_stack.top());
operator_stack.pop();
}
return true;
}
bool parse_statement(Template &tmpl, Token::Kind closing, nonstd::string_view path) {
if (tok.kind != Token::Kind::Id) {
return false;
}
if (tok.text == static_cast<decltype(tok.text)>("if")) {
get_next_token();
auto if_statement_node = std::make_shared<IfStatementNode>(current_block, tok.text.data() - tmpl.content.c_str());
current_block->nodes.emplace_back(if_statement_node);
if_statement_stack.emplace(if_statement_node.get());
current_block = &if_statement_node->true_statement;
current_expression_list = &if_statement_node->condition;
if (!parse_expression(tmpl, closing)) {
return false;
}
} else if (tok.text == static_cast<decltype(tok.text)>("else")) {
if (if_statement_stack.empty()) {
throw_parser_error("else without matching if");
}
auto &if_statement_data = if_statement_stack.top();
get_next_token();
if_statement_data->has_false_statement = true;
current_block = &if_statement_data->false_statement;
// Chained else if
if (tok.kind == Token::Kind::Id && tok.text == static_cast<decltype(tok.text)>("if")) {
get_next_token();
auto if_statement_node = std::make_shared<IfStatementNode>(true, current_block, tok.text.data() - tmpl.content.c_str());
current_block->nodes.emplace_back(if_statement_node);
if_statement_stack.emplace(if_statement_node.get());
current_block = &if_statement_node->true_statement;
current_expression_list = &if_statement_node->condition;
if (!parse_expression(tmpl, closing)) {
return false;
}
}
} else if (tok.text == static_cast<decltype(tok.text)>("endif")) {
if (if_statement_stack.empty()) {
throw_parser_error("endif without matching if");
}
// Nested if statements
while (if_statement_stack.top()->is_nested) {
if_statement_stack.pop();
}
auto &if_statement_data = if_statement_stack.top();
get_next_token();
current_block = if_statement_data->parent;
if_statement_stack.pop();
} else if (tok.text == static_cast<decltype(tok.text)>("for")) {
get_next_token();
// options: for a in arr; for a, b in obj
if (tok.kind != Token::Kind::Id) {
throw_parser_error("expected id, got '" + tok.describe() + "'");
}
Token value_token = tok;
get_next_token();
// Object type
std::shared_ptr<ForStatementNode> for_statement_node;
if (tok.kind == Token::Kind::Comma) {
get_next_token();
if (tok.kind != Token::Kind::Id) {
throw_parser_error("expected id, got '" + tok.describe() + "'");
}
Token key_token = std::move(value_token);
value_token = tok;
get_next_token();
for_statement_node = std::make_shared<ForObjectStatementNode>(static_cast<std::string>(key_token.text), static_cast<std::string>(value_token.text), current_block, tok.text.data() - tmpl.content.c_str());
// Array type
} else {
for_statement_node = std::make_shared<ForArrayStatementNode>(static_cast<std::string>(value_token.text), current_block, tok.text.data() - tmpl.content.c_str());
}
current_block->nodes.emplace_back(for_statement_node);
for_statement_stack.emplace(for_statement_node.get());
current_block = &for_statement_node->body;
current_expression_list = &for_statement_node->condition;
if (tok.kind != Token::Kind::Id || tok.text != static_cast<decltype(tok.text)>("in")) {
throw_parser_error("expected 'in', got '" + tok.describe() + "'");
}
get_next_token();
if (!parse_expression(tmpl, closing)) {
return false;
}
} else if (tok.text == static_cast<decltype(tok.text)>("endfor")) {
if (for_statement_stack.empty()) {
throw_parser_error("endfor without matching for");
}
auto &for_statement_data = for_statement_stack.top();
get_next_token();
current_block = for_statement_data->parent;
for_statement_stack.pop();
} else if (tok.text == static_cast<decltype(tok.text)>("include")) {
get_next_token();
if (tok.kind != Token::Kind::String) {
throw_parser_error("expected string, got '" + tok.describe() + "'");
}
// Build the relative path
json json_name = json::parse(tok.text);
std::string pathname = static_cast<std::string>(path);
pathname += json_name.get_ref<const std::string &>();
if (pathname.compare(0, 2, "./") == 0) {
pathname.erase(0, 2);
}
// sys::path::remove_dots(pathname, true, sys::path::Style::posix);
if (config.search_included_templates_in_files && template_storage.find(pathname) == template_storage.end()) {
auto include_template = Template(load_file(pathname));
template_storage.emplace(pathname, include_template);
parse_into_template(template_storage[pathname], pathname);
}
current_block->nodes.emplace_back(std::make_shared<IncludeStatementNode>(pathname, tok.text.data() - tmpl.content.c_str()));
get_next_token();
} else if (tok.text == static_cast<decltype(tok.text)>("set")) {
get_next_token();
if (tok.kind != Token::Kind::Id) {
throw_parser_error("expected variable name, got '" + tok.describe() + "'");
}
std::string key = static_cast<std::string>(tok.text);
get_next_token();
auto set_statement_node = std::make_shared<SetStatementNode>(key, tok.text.data() - tmpl.content.c_str());
current_block->nodes.emplace_back(set_statement_node);
current_expression_list = &set_statement_node->expression;
if (tok.text != static_cast<decltype(tok.text)>("=")) {
throw_parser_error("expected '=', got '" + tok.describe() + "'");
}
get_next_token();
if (!parse_expression(tmpl, closing)) {
return false;
}
} else {
return false;
}
return true;
}
void parse_into(Template &tmpl, nonstd::string_view path) {
lexer.start(tmpl.content);
current_block = &tmpl.root;
for (;;) {
get_next_token();
switch (tok.kind) {
case Token::Kind::Eof: {
if (!if_statement_stack.empty()) {
throw_parser_error("unmatched if");
}
if (!for_statement_stack.empty()) {
throw_parser_error("unmatched for");
}
} return;
case Token::Kind::Text: {
current_block->nodes.emplace_back(std::make_shared<TextNode>(tok.text.data() - tmpl.content.c_str(), tok.text.size()));
} break;
case Token::Kind::StatementOpen: {
get_next_token();
if (!parse_statement(tmpl, Token::Kind::StatementClose, path)) {
throw_parser_error("expected statement, got '" + tok.describe() + "'");
}
if (tok.kind != Token::Kind::StatementClose) {
throw_parser_error("expected statement close, got '" + tok.describe() + "'");
}
} break;
case Token::Kind::LineStatementOpen: {
get_next_token();
if (!parse_statement(tmpl, Token::Kind::LineStatementClose, path)) {
throw_parser_error("expected statement, got '" + tok.describe() + "'");
}
if (tok.kind != Token::Kind::LineStatementClose && tok.kind != Token::Kind::Eof) {
throw_parser_error("expected line statement close, got '" + tok.describe() + "'");
}
} break;
case Token::Kind::ExpressionOpen: {
get_next_token();
auto expression_list_node = std::make_shared<ExpressionListNode>(tok.text.data() - tmpl.content.c_str());
current_block->nodes.emplace_back(expression_list_node);
current_expression_list = expression_list_node.get();
if (!parse_expression(tmpl, Token::Kind::ExpressionClose)) {
throw_parser_error("expected expression, got '" + tok.describe() + "'");
}
if (tok.kind != Token::Kind::ExpressionClose) {
throw_parser_error("expected expression close, got '" + tok.describe() + "'");
}
} break;
case Token::Kind::CommentOpen: {
get_next_token();
if (tok.kind != Token::Kind::CommentClose) {
throw_parser_error("expected comment close, got '" + tok.describe() + "'");
}
} break;
default: {
throw_parser_error("unexpected token '" + tok.describe() + "'");
} break;
}
}
}
public:
explicit Parser(const ParserConfig &parser_config, const LexerConfig &lexer_config,
TemplateStorage &template_storage, const FunctionStorage &function_storage)
: config(parser_config), lexer(lexer_config), template_storage(template_storage), function_storage(function_storage) { }
Template parse(nonstd::string_view input, nonstd::string_view path) {
auto result = Template(static_cast<std::string>(input));
parse_into(result, path);
return result;
}
Template parse(nonstd::string_view input) {
return parse(input, "./");
}
void parse_into_template(Template& tmpl, nonstd::string_view filename) {
nonstd::string_view path = filename.substr(0, filename.find_last_of("/\\") + 1);
// StringRef path = sys::path::parent_path(filename);
auto sub_parser = Parser(config, lexer.get_config(), template_storage, function_storage);
sub_parser.parse_into(tmpl, path);
}
std::string load_file(nonstd::string_view filename) {
std::ifstream file;
open_file_or_throw(static_cast<std::string>(filename), file);
std::string text((std::istreambuf_iterator<char>(file)), std::istreambuf_iterator<char>());
return text;
}
};
} // namespace inja
#endif // INCLUDE_INJA_PARSER_HPP_