#pragma once
#include "json.h"
#include <memory>
#include <set>
#include <unordered_map>
#include <string>
#include <string_view>
#include <functional>
#include <vector>
#include <variant>
struct common_grammar_builder;
class common_peg_parser_builder;
using common_peg_parser_id = size_t;
constexpr common_peg_parser_id COMMON_PEG_INVALID_PARSER_ID = static_cast<common_peg_parser_id>(-1);
using common_peg_ast_id = size_t;
constexpr common_peg_ast_id COMMON_PEG_INVALID_AST_ID = static_cast<common_peg_ast_id>(-1);
// Lightweight wrapper around common_peg_parser_id for convenience
class common_peg_parser {
common_peg_parser_id id_;
common_peg_parser_builder & builder_;
public:
common_peg_parser(const common_peg_parser & other) : id_(other.id_), builder_(other.builder_) {}
common_peg_parser(common_peg_parser_id id, common_peg_parser_builder & builder) : id_(id), builder_(builder) {}
common_peg_parser & operator=(const common_peg_parser & other);
common_peg_parser & operator+=(const common_peg_parser & other);
common_peg_parser & operator|=(const common_peg_parser & other);
operator common_peg_parser_id() const { return id_; }
common_peg_parser_id id() const { return id_; }
common_peg_parser_builder & builder() const { return builder_; }
// Creates a sequence
common_peg_parser operator+(const common_peg_parser & other) const;
// Creates a sequence separated by spaces.
common_peg_parser operator<<(const common_peg_parser & other) const;
// Creates a choice
common_peg_parser operator|(const common_peg_parser & other) const;
common_peg_parser operator+(const char * str) const;
common_peg_parser operator+(const std::string & str) const;
common_peg_parser operator<<(const char * str) const;
common_peg_parser operator<<(const std::string & str) const;
common_peg_parser operator|(const char * str) const;
common_peg_parser operator|(const std::string & str) const;
};
common_peg_parser operator+(const char * str, const common_peg_parser & p);
common_peg_parser operator+(const std::string & str, const common_peg_parser & p);
common_peg_parser operator<<(const char * str, const common_peg_parser & p);
common_peg_parser operator<<(const std::string & str, const common_peg_parser & p);
common_peg_parser operator|(const char * str, const common_peg_parser & p);
common_peg_parser operator|(const std::string & str, const common_peg_parser & p);
enum common_peg_parse_result_type {
COMMON_PEG_PARSE_RESULT_FAIL = 0,
COMMON_PEG_PARSE_RESULT_SUCCESS = 1,
COMMON_PEG_PARSE_RESULT_NEED_MORE_INPUT = 2,
};
const char * common_peg_parse_result_type_name(common_peg_parse_result_type type);
struct common_peg_ast_node {
common_peg_ast_id id;
std::string rule;
std::string tag;
size_t start;
size_t end;
std::string_view text;
std::vector<common_peg_ast_id> children;
bool is_partial = false;
};
struct common_peg_parse_result;
using common_peg_ast_visitor = std::function<void(const common_peg_ast_node & node)>;
class common_peg_ast_arena {
std::vector<common_peg_ast_node> nodes_;
public:
common_peg_ast_id add_node(
const std::string & rule,
const std::string & tag,
size_t start,
size_t end,
std::string_view text,
std::vector<common_peg_ast_id> children,
bool is_partial = false
) {
common_peg_ast_id id = nodes_.size();
nodes_.push_back({id, rule, tag, start, end, text, std::move(children), is_partial});
return id;
}
const common_peg_ast_node & get(common_peg_ast_id id) const { return nodes_.at(id); }
common_peg_ast_id find_by_tag(const common_peg_ast_node & parent, const std::string & tag, int max_depth = 3) const;
common_peg_ast_id find_by_rule(const common_peg_ast_node & parent, const std::string & tag, int max_depth = 3) const;
size_t size() const { return nodes_.size(); }
void clear() { nodes_.clear(); }
void visit(common_peg_ast_id id, const common_peg_ast_visitor & visitor) const;
void visit(const common_peg_parse_result & result, const common_peg_ast_visitor & visitor) const;
std::string dump();
};
struct common_peg_parse_result {
common_peg_parse_result_type type = COMMON_PEG_PARSE_RESULT_FAIL;
size_t start = 0;
size_t end = 0;
std::vector<common_peg_ast_id> nodes;
common_peg_parse_result() = default;
common_peg_parse_result(common_peg_parse_result_type type, size_t start)
: type(type), start(start), end(start) {}
common_peg_parse_result(common_peg_parse_result_type type, size_t start, size_t end)
: type(type), start(start), end(end) {}
common_peg_parse_result(common_peg_parse_result_type type, size_t start, size_t end, std::vector<common_peg_ast_id> nodes)
: type(type), start(start), end(end), nodes(std::move(nodes)) {}
bool fail() const { return type == COMMON_PEG_PARSE_RESULT_FAIL; }
bool need_more_input() const { return type == COMMON_PEG_PARSE_RESULT_NEED_MORE_INPUT; }
bool success() const { return type == COMMON_PEG_PARSE_RESULT_SUCCESS; }
};
enum common_peg_parse_flags {
COMMON_PEG_PARSE_FLAG_NONE = 0,
COMMON_PEG_PARSE_FLAG_LENIENT = 1 << 0,
COMMON_PEG_PARSE_FLAG_DEBUG = 1 << 1,
};
inline common_peg_parse_flags operator|(common_peg_parse_flags a, common_peg_parse_flags b) {
return static_cast<common_peg_parse_flags>(int(a) | int(b));
}
inline common_peg_parse_flags & operator|=(common_peg_parse_flags & a, common_peg_parse_flags b) {
return a = a | b;
}
inline common_peg_parse_flags operator&(common_peg_parse_flags a, common_peg_parse_flags b) {
return static_cast<common_peg_parse_flags>(int(a) & int(b));
}
inline common_peg_parse_flags operator~(common_peg_parse_flags a) {
return static_cast<common_peg_parse_flags>(~int(a));
}
struct common_peg_parse_context {
std::string input;
common_peg_parse_flags flags;
common_peg_ast_arena ast;
int parse_depth;
common_peg_parse_context(common_peg_parse_flags flags = COMMON_PEG_PARSE_FLAG_NONE)
: flags(flags), parse_depth(0) {}
common_peg_parse_context(const std::string & input, common_peg_parse_flags flags = COMMON_PEG_PARSE_FLAG_NONE)
: input(input), flags(flags), parse_depth(0) {}
bool is_lenient() const { return flags & COMMON_PEG_PARSE_FLAG_LENIENT; }
bool is_debug() const { return flags & COMMON_PEG_PARSE_FLAG_DEBUG; }
};
class common_peg_arena;
// Parser variants
struct common_peg_epsilon_parser {};
struct common_peg_start_parser {};
struct common_peg_end_parser {};
struct common_peg_literal_parser {
std::string literal;
};
struct common_peg_sequence_parser {
std::vector<common_peg_parser_id> children;
};
struct common_peg_choice_parser {
std::vector<common_peg_parser_id> children;
};
struct common_peg_repetition_parser {
common_peg_parser_id child;
int min_count;
int max_count; // -1 for unbounded
};
struct common_peg_and_parser {
common_peg_parser_id child;
};
struct common_peg_not_parser {
common_peg_parser_id child;
};
struct common_peg_any_parser {};
struct common_peg_space_parser {};
struct common_peg_chars_parser {
struct char_range {
uint32_t start;
uint32_t end;
bool contains(uint32_t codepoint) const { return codepoint >= start && codepoint <= end; }
};
std::string pattern;
std::vector<char_range> ranges;
bool negated;
int min_count;
int max_count; // -1 for unbounded
};
struct common_peg_string_parser {
char delimiter;
};
struct common_peg_until_parser {
std::vector<std::string> delimiters;
};
struct common_peg_schema_parser {
common_peg_parser_id child;
std::string name;
std::shared_ptr<common_json> schema;
// Indicates if the GBNF should accept a raw string that matches the schema.
bool raw;
};
struct common_peg_rule_parser {
std::string name;
common_peg_parser_id child;
bool trigger;
};
struct common_peg_ref_parser {
std::string name;
};
struct common_peg_atomic_parser {
common_peg_parser_id child;
};
struct common_peg_tag_parser {
common_peg_parser_id child;
std::string tag;
};
struct common_peg_gbnf_parser {
common_peg_parser_id child;
std::string grammar;
};
struct common_peg_ac_parser {
common_peg_parser_id child;
std::vector<std::string> delimiters;
};
// Variant holding all parser types
using common_peg_parser_variant = std::variant<
common_peg_epsilon_parser,
common_peg_start_parser,
common_peg_end_parser,
common_peg_literal_parser,
common_peg_sequence_parser,
common_peg_choice_parser,
common_peg_repetition_parser,
common_peg_and_parser,
common_peg_not_parser,
common_peg_any_parser,
common_peg_space_parser,
common_peg_chars_parser,
common_peg_string_parser,
common_peg_until_parser,
common_peg_schema_parser,
common_peg_rule_parser,
common_peg_ref_parser,
common_peg_atomic_parser,
common_peg_tag_parser,
common_peg_gbnf_parser,
common_peg_ac_parser
>;
class common_peg_arena {
std::vector<common_peg_parser_variant> parsers_;
std::unordered_map<std::string, common_peg_parser_id> rules_;
common_peg_parser_id root_ = COMMON_PEG_INVALID_PARSER_ID;
public:
const common_peg_parser_variant & get(common_peg_parser_id id) const { return parsers_.at(id); }
common_peg_parser_variant & get(common_peg_parser_id id) { return parsers_.at(id); }
size_t size() const { return parsers_.size(); }
bool empty() const { return parsers_.empty(); }
common_peg_parser_id get_rule(const std::string & name) const;
bool has_rule(const std::string & name) const { return rules_.find(name) != rules_.end(); }
common_peg_parser_id root() const { return root_; }
void set_root(common_peg_parser_id id) { root_ = id; }
common_peg_parse_result parse(common_peg_parse_context & ctx, size_t start = 0) const;
common_peg_parse_result parse(common_peg_parser_id id, common_peg_parse_context & ctx, size_t start) const;
void resolve_refs();
void build_grammar(const common_grammar_builder & builder, bool lazy = false) const;
std::string dump(common_peg_parser_id id) const;
common_json to_json() const;
static common_peg_arena from_json(const common_json & j);
std::string save() const;
void load(const std::string & data);
friend class common_peg_parser_builder;
private:
std::string dump_impl(common_peg_parser_id id, std::set<common_peg_parser_id> & visited) const;
common_peg_parser_id add_parser(common_peg_parser_variant parser);
void add_rule(const std::string & name, common_peg_parser_id id);
common_peg_parser_id resolve_ref(common_peg_parser_id id);
};
class common_peg_parser_builder {
common_peg_arena arena_;
common_peg_parser wrap(common_peg_parser_id id) { return common_peg_parser(id, *this); }
common_peg_parser add(const common_peg_parser_variant & p) { return wrap(arena_.add_parser(p)); }
public:
common_peg_parser_builder();
// Match nothing, always succeed.
// S -> ε
common_peg_parser eps() { return add(common_peg_epsilon_parser{}); }
// Matches the start of the input.
// S -> ^
common_peg_parser start() { return add(common_peg_start_parser{}); }
// Matches the end of the input.
// S -> $
common_peg_parser end() { return add(common_peg_end_parser{}); }
// Matches an exact literal string.
// S -> "hello"
common_peg_parser literal(const std::string & literal) { return add(common_peg_literal_parser{literal}); }
// Matches a sequence of parsers in order, all must succeed.
// S -> A B C
common_peg_parser sequence() { return add(common_peg_sequence_parser{}); }
common_peg_parser sequence(const std::vector<common_peg_parser_id> & parsers);
common_peg_parser sequence(const std::vector<common_peg_parser> & parsers);
common_peg_parser sequence(std::initializer_list<common_peg_parser> parsers);
// Matches the first parser that succeeds from a list of alternatives.
// S -> A | B | C
common_peg_parser choice() { return add(common_peg_choice_parser{}); }
common_peg_parser choice(const std::vector<common_peg_parser_id> & parsers);
common_peg_parser choice(const std::vector<common_peg_parser> & parsers);
common_peg_parser choice(std::initializer_list<common_peg_parser> parsers);
// Matches one or more repetitions of a parser.
// S -> A+
common_peg_parser one_or_more(const common_peg_parser & p) { return repeat(p, 1, -1); }
// Matches zero or more repetitions of a parser, always succeeds.
// S -> A*
common_peg_parser zero_or_more(const common_peg_parser & p) { return repeat(p, 0, -1); }
// Matches zero or one occurrence of a parser, always succeeds.
// S -> A?
common_peg_parser optional(const common_peg_parser & p) { return repeat(p, 0, 1); }
// Positive lookahead: succeeds if child parser succeeds, consumes no input.
// S -> &A
common_peg_parser peek(const common_peg_parser & p) { return add(common_peg_and_parser{p}); }
// Negative lookahead: succeeds if child parser fails, consumes no input.
// S -> !A
common_peg_parser negate(const common_peg_parser & p) { return add(common_peg_not_parser{p}); }
// Matches any single character.
// S -> .
common_peg_parser any() { return add(common_peg_any_parser{}); }
// Matches between min and max repetitions of characters from a character class.
// S -> [a-z]{m,n}
//
// Use -1 for max to represent unbounded repetition (equivalent to {m,})
common_peg_parser chars(const std::string & classes, int min = 1, int max = -1);
// Creates a lightweight reference to a named rule (resolved during build()).
// Use this for forward references in recursive grammars.
// expr_ref -> expr
common_peg_parser ref(const std::string & name) { return add(common_peg_ref_parser{name}); }
// Matches zero or more whitespace characters (space, tab, newline).
// S -> [ \t\n]*
common_peg_parser space() { return add(common_peg_space_parser{}); }
// Matches all characters until a delimiter is found (delimiter not consumed).
// S -> (!delim .)*
common_peg_parser until(const std::string & delimiter) { return add(common_peg_until_parser{{delimiter}}); }
// Matches all characters until one of the delimiters in the list is found (delimiter not consumed).
// S -> (!delim .)*
common_peg_parser until_one_of(const std::vector<std::string> & delimiters) { return add(common_peg_until_parser{delimiters}); }
// Matches everything
// S -> .*
common_peg_parser rest() { return until_one_of({}); }
// Matches between min and max repetitions of a parser (inclusive).
// S -> A{m,n}
// Use -1 for max to represent unbounded repetition (equivalent to {m,})
common_peg_parser repeat(const common_peg_parser & p, int min, int max) { return add(common_peg_repetition_parser{p, min,max}); }
// Matches exactly n repetitions of a parser.
// S -> A{n}
common_peg_parser repeat(const common_peg_parser & p, int n) { return repeat(p, n, n); }
// Matches a double-quoted string: '"' content '"' space
common_peg_parser double_quoted_string();
// Matches a single-quoted string: "'" content "'" space
common_peg_parser single_quoted_string();
// Matches a string that accepts both double-quoted and single-quoted styles.
common_peg_parser quoted_string();
// Matches string content without the surrounding delimiter.
common_peg_parser string_content(char delimiter);
// Creates a complete JSON parser supporting objects, arrays, strings, numbers, booleans, and null.
// value -> object | array | string | number | true | false | null
common_peg_parser json();
common_peg_parser json_object();
common_peg_parser json_string();
common_peg_parser json_array();
common_peg_parser json_number();
common_peg_parser json_bool();
common_peg_parser json_null();
// Matches a JSON object member with a key and associated parser as the
// value.
common_peg_parser json_member(const std::string & key, const common_peg_parser & p);
// Creates a complete Python format parser supporting dicts, arrays, strings, numbers, booleans, and None.
// Differs from JSON: uses True/False/None, accepts both single and double-quoted strings.
// value -> dict | array | string | number | True | False | None
common_peg_parser python_value();
common_peg_parser python_dict();
common_peg_parser python_string();
common_peg_parser python_array();
common_peg_parser python_number();
common_peg_parser python_bool();
common_peg_parser python_null();
// A marker, i.e. text delimited by a pair of <> or []
common_peg_parser marker();
// Wraps a parser with JSON schema metadata for grammar generation.
// Used internally to convert JSON schemas to GBNF grammar rules.
common_peg_parser schema(const common_peg_parser & p, const std::string & name, const common_json & schema, bool raw = false);
// Creates a named rule, stores it in the grammar, and returns a ref.
// If trigger=true, marks this rule as an entry point for lazy grammar generation.
// auto json = p.rule("json", json_obj | json_arr | ...)
common_peg_parser rule(const std::string & name, const common_peg_parser & p, bool trigger = false);
// Creates a named rule using a builder function, and returns a ref.
// If trigger=true, marks this rule as an entry point for lazy grammar generation.
// auto json = p.rule("json", [&]() { return json_object() | json_array() | ... })
common_peg_parser rule(const std::string & name, const std::function<common_peg_parser()> & builder, bool trigger = false);
// Creates a trigger rule. When generating a lazy grammar from the parser,
// only trigger rules and descendents are emitted.
common_peg_parser trigger_rule(const std::string & name, const common_peg_parser & p) { return rule(name, p, true); }
common_peg_parser trigger_rule(const std::string & name, const std::function<common_peg_parser()> & builder) { return rule(name, builder, true); }
// Creates an atomic parser. Atomic parsers do not create an AST node if
// the child results in a partial parse, i.e. NEEDS_MORE_INPUT. This is
// intended for situations where partial output is undesirable.
common_peg_parser atomic(const common_peg_parser & p) { return add(common_peg_atomic_parser{p}); }
// Tags create nodes in the generated AST for semantic purposes.
// Unlike rules, you can tag multiple nodes with the same tag.
common_peg_parser tag(const std::string & tag, const common_peg_parser & p) { return add(common_peg_tag_parser{p.id(), tag}); }
// Wraps a child parser but emits a custom GBNF grammar string instead of
// the child's grammar. Parsing delegates entirely to the child.
common_peg_parser gbnf(const common_peg_parser & p, const std::string & grammar) { return add(common_peg_gbnf_parser{p, grammar}); }
// Wraps a child parser but emits a GBNF grammar built from the Aho-Corasick
// automaton of `delimiters`, matching everything up to and including the
// first delimiter. Parsing delegates entirely to the child, which is
// responsible for consuming the delimiter (e.g. until(D) + literal(D)).
common_peg_parser ac(const common_peg_parser & p, const std::vector<std::string> & delimiters);
common_peg_parser ac(const common_peg_parser & p, const std::string & delimiter) { return ac(p, std::vector<std::string>{delimiter}); }
void set_root(const common_peg_parser & p);
common_peg_arena build();
};
// Helper function for building parsers
common_peg_arena build_peg_parser(const std::function<common_peg_parser(common_peg_parser_builder & builder)> & fn);