llama.cpp/common/json-schema-to-grammar.cpp
Olivier Chafik 5b7b0ac8df
json-schema-to-grammar improvements (+ added to server) (#5978)
* json: fix arrays (disallow `[,1]`)

* json: support tuple types (`[number, string]`)

* json: support additionalProperties (`{[k: string]: [string,number][]}`)

* json: support required / optional properties

* json: add support for pattern

* json: resolve $ref (and support https schema urls)

* json: fix $ref resolution

* join: support union types (mostly for nullable types I think)

* json: support allOf + nested anyOf

* json: support any (`{}` or `{type: object}`)

* json: fix merge

* json: temp fix for escapes

* json: spaces in output and unrestricted output spaces

* json: add typings

* json:fix typo

* Create ts-type-to-grammar.sh

* json: fix _format_literal (json.dumps already escapes quotes)

* json: merge lit sequences and handle negatives

{"type": "string", "pattern": "^({\"question\": \"[^\"]+\", \"response\": \"[^\"]+\"}\\n)+$"}

* json: handle pattern repetitions

* Update json-schema-to-grammar.mjs

* Create regex-to-grammar.py

* json: extract repeated regexp patterns to subrule

* Update json-schema-to-grammar.py

* Update json-schema-to-grammar.py

* Update json-schema-to-grammar.py

* json: handle schema from pydantic Optional fields

* Update json-schema-to-grammar.py

* Update json-schema-to-grammar.py

* Update ts-type-to-grammar.sh

* Update ts-type-to-grammar.sh

* json: simplify nullable fields handling

* json: accept duplicate identical rules

* json: revert space to 1 at most

* json: reuse regexp pattern subrules

* json: handle uuid string format

* json: fix literal escapes

* json: add --allow-fetch

* json: simplify range escapes

* json: support negative ranges in patterns

* Delete commit.txt

* json: custom regex parser, adds dot support & JS-portable

* json: rm trailing spaces

* Update json-schema-to-grammar.mjs

* json: updated server & chat `( cd examples/server && ./deps.sh )`

* json: port fixes from mjs to python

* Update ts-type-to-grammar.sh

* json: support prefixItems alongside array items

* json: add date format + fix uuid

* json: add date, time, date-time formats

* json: preserve order of props from TS defs

* json: port schema converter to C++, wire in ./server

* json: nits

* Update json-schema-to-grammar.cpp

* Update json-schema-to-grammar.cpp

* Update json-schema-to-grammar.cpp

* json: fix mjs implementation + align outputs

* Update json-schema-to-grammar.mjs.hpp

* json: test C++, JS & Python versions

* json: nits + regen deps

* json: cleanup test

* json: revert from c++17 to 11

* json: nit fixes

* json: dirty include for test

* json: fix zig build

* json: pass static command to std::system in tests (fixed temp files)

* json: fix top-level $refs

* json: don't use c++20 designated initializers

* nit

* json: basic support for reserved names `{number:{number:{root:number}}}`

* Revamp test cmake to allow args (WORKING_DIRECTORY needed for JSON test)

* json: re-ran server deps.sh

* json: simplify test

* json: support mix of additional props & required/optional

* json: add tests for some expected failures

* json: fix type=const in c++, add failure expectations for non-str const&enum

* json: test (& simplify output of) empty schema

* json: check parsing in test + fix value & string refs

* json: add server tests for OAI JSON response_format

* json: test/fix top-level anyOf

* json: improve grammar parsing failures

* json: test/fix additional props corner cases

* json: fix string patterns (was missing quotes)

* json: ws nit

* json: fix json handling in server when there's no response_format

* json: catch schema conversion errors in server

* json: don't complain about unknown format type in server if unset

* json: cleaner build of test

* json: create examples/json-schema-pydantic-example.py

* json: fix date pattern

* json: move json.hpp & json-schema-to-grammar.{cpp,h} to common

* json: indent 4 spaces

* json: fix naming of top-level c++ function (+ drop unused one)

* json: avoid using namespace std

* json: fix zig build

* Update server.feature

* json: iostream -> fprintf

* json: space before & refs for consistency

* json: nits
2024-03-21 11:50:43 +00:00

726 lines
32 KiB
C++

#include "json-schema-to-grammar.h"
#include <algorithm>
#include <fstream>
#include <map>
#include <regex>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>
using json = nlohmann::json;
const std::string SPACE_RULE = "\" \"?";
std::unordered_map<std::string, std::string> PRIMITIVE_RULES = {
{"boolean", "(\"true\" | \"false\") space"},
{"number", "(\"-\"? ([0-9] | [1-9] [0-9]*)) (\".\" [0-9]+)? ([eE] [-+]? [0-9]+)? space"},
{"integer", "(\"-\"? ([0-9] | [1-9] [0-9]*)) space"},
{"value", "object | array | string | number | boolean"},
{"object", "\"{\" space ( string \":\" space value (\",\" space string \":\" space value)* )? \"}\" space"},
{"array", "\"[\" space ( value (\",\" space value)* )? \"]\" space"},
{"uuid", "\"\\\"\" [0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F] "
"\"-\" [0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F] "
"\"-\" [0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F] "
"\"-\" [0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F] "
"\"-\" [0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F] \"\\\"\" space"},
{"string", " \"\\\"\" (\n"
" [^\"\\\\] |\n"
" \"\\\\\" ([\"\\\\/bfnrt] | \"u\" [0-9a-fA-F] [0-9a-fA-F] [0-9a-fA-F] [0-9a-fA-F])\n"
" )* \"\\\"\" space"},
{"null", "\"null\" space"}
};
std::vector<std::string> OBJECT_RULE_NAMES = {"object", "array", "string", "number", "boolean", "null", "value"};
std::unordered_map<std::string, std::string> DATE_RULES = {
{"date", "[0-9] [0-9] [0-9] [0-9] \"-\" ( \"0\" [1-9] | \"1\" [0-2] ) \"-\" ( \"0\" [1-9] | [1-2] [0-9] | \"3\" [0-1] )"},
{"time", "([01] [0-9] | \"2\" [0-3]) \":\" [0-5] [0-9] \":\" [0-5] [0-9] ( \".\" [0-9] [0-9] [0-9] )? ( \"Z\" | ( \"+\" | \"-\" ) ( [01] [0-9] | \"2\" [0-3] ) \":\" [0-5] [0-9] )"},
{"date-time", "date \"T\" time"},
{"date-string", "\"\\\"\" date \"\\\"\" space"},
{"time-string", "\"\\\"\" time \"\\\"\" space"},
{"date-time-string", "\"\\\"\" date-time \"\\\"\" space"}
};
static bool is_reserved_name(const std::string & name) {
static std::unordered_set<std::string> RESERVED_NAMES;
if (RESERVED_NAMES.empty()) {
RESERVED_NAMES.insert("root");
for (const auto &p : PRIMITIVE_RULES) RESERVED_NAMES.insert(p.first);
for (const auto &p : DATE_RULES) RESERVED_NAMES.insert(p.first);
}
return RESERVED_NAMES.find(name) != RESERVED_NAMES.end();
}
std::regex INVALID_RULE_CHARS_RE("[^a-zA-Z0-9-]+");
std::regex GRAMMAR_LITERAL_ESCAPE_RE("[\r\n\"]");
std::regex GRAMMAR_RANGE_LITERAL_ESCAPE_RE("[\r\n\"\\]\\-\\\\]");
std::unordered_map<char, std::string> GRAMMAR_LITERAL_ESCAPES = {
{'\r', "\\r"}, {'\n', "\\n"}, {'"', "\\\""}, {'-', "\\-"}, {']', "\\]"}
};
std::unordered_set<char> NON_LITERAL_SET = {'|', '.', '(', ')', '[', ']', '{', '}', '*', '+', '?'};
std::unordered_set<char> ESCAPED_IN_REGEXPS_BUT_NOT_IN_LITERALS = {'[', ']', '(', ')', '|', '{', '}', '*', '+', '?'};
template <typename Iterator>
std::string join(Iterator begin, Iterator end, const std::string & separator) {
std::ostringstream result;
if (begin != end) {
result << *begin;
for (Iterator it = begin + 1; it != end; ++it) {
result << separator << *it;
}
}
return result.str();
}
static std::vector<std::string> split(const std::string & str, const std::string & delimiter) {
std::vector<std::string> tokens;
size_t start = 0;
size_t end = str.find(delimiter);
while (end != std::string::npos) {
tokens.push_back(str.substr(start, end - start));
start = end + delimiter.length();
end = str.find(delimiter, start);
}
tokens.push_back(str.substr(start));
return tokens;
}
static std::string repeat(const std::string & str, size_t n) {
if (n == 0) {
return "";
}
std::string result;
result.reserve(str.length() * n);
for (size_t i = 0; i < n; ++i) {
result += str;
}
return result;
}
static std::string replacePattern(const std::string & input, const std::regex & regex, const std::function<std::string(const std::smatch &)> & replacement) {
std::smatch match;
std::string result;
std::string::const_iterator searchStart(input.cbegin());
std::string::const_iterator searchEnd(input.cend());
while (std::regex_search(searchStart, searchEnd, match, regex)) {
result.append(searchStart, searchStart + match.position());
result.append(replacement(match));
searchStart = match.suffix().first;
}
result.append(searchStart, searchEnd);
return result;
}
static std::string format_literal(const std::string & literal) {
std::string escaped = replacePattern(json(literal).dump(), GRAMMAR_LITERAL_ESCAPE_RE, [&](const std::smatch & match) {
char c = match.str()[0];
return GRAMMAR_LITERAL_ESCAPES.at(c);
});
return "\"" + escaped + "\"";
}
class SchemaConverter {
private:
std::function<json(const std::string &)> _fetch_json;
bool _dotall;
std::map<std::string, std::string> _rules;
std::unordered_map<std::string, nlohmann::json> _refs;
std::unordered_set<std::string> _refs_being_resolved;
std::vector<std::string> _errors;
std::vector<std::string> _warnings;
std::string _add_rule(const std::string & name, const std::string & rule) {
std::string esc_name = regex_replace(name, INVALID_RULE_CHARS_RE, "-");
if (_rules.find(esc_name) == _rules.end() || _rules[esc_name] == rule) {
_rules[esc_name] = rule;
return esc_name;
} else {
int i = 0;
while (_rules.find(esc_name + std::to_string(i)) != _rules.end() && _rules[esc_name + std::to_string(i)] != rule) {
i++;
}
std::string key = esc_name + std::to_string(i);
_rules[key] = rule;
return key;
}
}
std::string _generate_union_rule(const std::string & name, const std::vector<json> & alt_schemas) {
std::vector<std::string> rules;
for (size_t i = 0; i < alt_schemas.size(); i++) {
rules.push_back(visit(alt_schemas[i], name + (name.empty() ? "alternative-" : "-") + std::to_string(i)));
}
return join(rules.begin(), rules.end(), " | ");
}
std::string _visit_pattern(const std::string & pattern, const std::string & name) {
if (!(pattern.front() == '^' && pattern.back() == '$')) {
_errors.push_back("Pattern must start with '^' and end with '$'");
return "";
}
std::string sub_pattern = pattern.substr(1, pattern.length() - 2);
std::unordered_map<std::string, std::string> sub_rule_ids;
size_t i = 0;
size_t length = sub_pattern.length();
using literal_or_rule = std::pair<std::string, bool>;
auto to_rule = [&](const literal_or_rule & ls) {
auto is_literal = ls.second;
auto s = ls.first;
return is_literal ? "\"" + s + "\"" : s;
};
std::function<literal_or_rule()> transform = [&]() -> literal_or_rule {
size_t start = i;
std::vector<literal_or_rule> seq;
auto get_dot = [&]() {
std::string rule;
if (_dotall) {
rule = "[\\U00000000-\\U0010FFFF]";
} else {
rule = "[\\U00000000-\\x09\\x0B\\x0C\\x0E-\\U0010FFFF]";
}
return _add_rule("dot", rule);
};
// Joins the sequence, merging consecutive literals together.
auto join_seq = [&]() {
std::vector<literal_or_rule> ret;
std::string literal;
auto flush_literal = [&]() {
if (literal.empty()) {
return false;
}
ret.push_back(std::make_pair(literal, true));
literal.clear();
return true;
};
for (const auto & item : seq) {
auto is_literal = item.second;
if (is_literal) {
literal += item.first;
} else {
flush_literal();
ret.push_back(item);
}
}
flush_literal();
std::vector<std::string> results;
for (const auto & item : ret) {
results.push_back(to_rule(item));
}
return std::make_pair(join(results.begin(), results.end(), " "), false);
};
while (i < length) {
char c = sub_pattern[i];
if (c == '.') {
seq.push_back(std::make_pair(get_dot(), false));
i++;
} else if (c == '(') {
i++;
if (i < length) {
if (sub_pattern[i] == '?') {
_warnings.push_back("Unsupported pattern syntax");
}
}
seq.push_back(std::make_pair("(" + to_rule(transform()) + ")", false));
} else if (c == ')') {
i++;
if (start > 0 && sub_pattern[start - 1] != '(') {
_errors.push_back("Unbalanced parentheses");
}
return join_seq();
} else if (c == '[') {
std::string square_brackets = std::string(1, c);
i++;
while (i < length && sub_pattern[i] != ']') {
if (sub_pattern[i] == '\\') {
square_brackets += sub_pattern.substr(i, 2);
i += 2;
} else {
square_brackets += sub_pattern[i];
i++;
}
}
if (i >= length) {
_errors.push_back("Unbalanced square brackets");
}
square_brackets += ']';
i++;
seq.push_back(std::make_pair(square_brackets, false));
} else if (c == '|') {
seq.push_back(std::make_pair("|", false));
i++;
} else if (c == '*' || c == '+' || c == '?') {
seq.back() = std::make_pair(to_rule(seq.back()) + c, false);
i++;
} else if (c == '{') {
std::string curly_brackets = std::string(1, c);
i++;
while (i < length && sub_pattern[i] != '}') {
curly_brackets += sub_pattern[i];
i++;
}
if (i >= length) {
_errors.push_back("Unbalanced curly brackets");
}
curly_brackets += '}';
i++;
auto nums = split(curly_brackets.substr(1, curly_brackets.length() - 2), ",");
int min_times = 0;
int max_times = std::numeric_limits<int>::max();
try {
if (nums.size() == 1) {
min_times = max_times = std::stoi(nums[0]);
} else if (nums.size() != 2) {
_errors.push_back("Wrong number of values in curly brackets");
} else {
if (!nums[0].empty()) {
min_times = std::stoi(nums[0]);
}
if (!nums[1].empty()) {
max_times = std::stoi(nums[1]);
}
}
} catch (const std::invalid_argument & e) {
_errors.push_back("Invalid number in curly brackets");
return std::make_pair("", false);
}
auto &last = seq.back();
auto &sub = last.first;
auto sub_is_literal = last.second;
if (min_times == 0 && max_times == std::numeric_limits<int>::max()) {
sub += "*";
} else if (min_times == 0 && max_times == 1) {
sub += "?";
} else if (min_times == 1 && max_times == std::numeric_limits<int>::max()) {
sub += "+";
} else {
if (!sub_is_literal) {
std::string & sub_id = sub_rule_ids[sub];
if (sub_id.empty()) {
sub_id = _add_rule(name + "-" + std::to_string(sub_rule_ids.size()), sub);
}
sub = sub_id;
}
std::string result;
if (sub_is_literal && min_times > 0) {
result = "\"" + repeat(sub.substr(1, sub.length() - 2), min_times) + "\"";
} else {
for (int j = 0; j < min_times; j++) {
if (j > 0) {
result += " ";
}
result += sub;
}
}
if (min_times > 0 && min_times < max_times) {
result += " ";
}
if (max_times == std::numeric_limits<int>::max()) {
result += sub + "*";
} else {
for (int j = min_times; j < max_times; j++) {
if (j > min_times) {
result += " ";
}
result += sub + "?";
}
}
seq.back().first = result;
seq.back().second = false;
}
} else {
std::string literal;
auto is_non_literal = [&](char c) {
return NON_LITERAL_SET.find(c) != NON_LITERAL_SET.end();
};
while (i < length) {
if (sub_pattern[i] == '\\' && i < length - 1) {
char next = sub_pattern[i + 1];
if (ESCAPED_IN_REGEXPS_BUT_NOT_IN_LITERALS.find(next) != ESCAPED_IN_REGEXPS_BUT_NOT_IN_LITERALS.end()) {
i++;
literal += sub_pattern[i];
i++;
} else {
literal += sub_pattern.substr(i, 2);
i += 2;
}
} else if (sub_pattern[i] == '"') {
literal += "\\\"";
i++;
} else if (!is_non_literal(sub_pattern[i]) &&
(i == length - 1 || literal.empty() || sub_pattern[i + 1] == '.' || !is_non_literal(sub_pattern[i + 1]))) {
literal += sub_pattern[i];
i++;
} else {
break;
}
}
if (!literal.empty()) {
seq.push_back(std::make_pair(literal, true));
}
}
}
return join_seq();
};
return _add_rule(name, "\"\\\"\" " + to_rule(transform()) + " \"\\\"\" space");
}
std::string _resolve_ref(const std::string & ref) {
std::string ref_name = ref.substr(ref.find_last_of('/') + 1);
if (_rules.find(ref_name) == _rules.end() && _refs_being_resolved.find(ref) == _refs_being_resolved.end()) {
_refs_being_resolved.insert(ref);
json resolved = _refs[ref];
ref_name = visit(resolved, ref_name);
_refs_being_resolved.erase(ref);
}
return ref_name;
}
std::string _build_object_rule(
const std::vector<std::pair<std::string, json>> & properties,
const std::unordered_set<std::string> & required,
const std::string & name,
const json & additional_properties)
{
std::vector<std::string> required_props;
std::vector<std::string> optional_props;
std::unordered_map<std::string, std::string> prop_kv_rule_names;
for (const auto & kv : properties) {
const auto &prop_name = kv.first;
const auto &prop_schema = kv.second;
std::string prop_rule_name = visit(prop_schema, name + (name.empty() ? "" : "-") + prop_name);
prop_kv_rule_names[prop_name] = _add_rule(
name + (name.empty() ? "" : "-") + prop_name + "-kv",
format_literal(prop_name) + " space \":\" space " + prop_rule_name
);
if (required.find(prop_name) != required.end()) {
required_props.push_back(prop_name);
} else {
optional_props.push_back(prop_name);
}
}
if (additional_properties.is_object() || (additional_properties.is_boolean() && additional_properties.get<bool>())) {
std::string sub_name = name + (name.empty() ? "" : "-") + "additional";
std::string value_rule = visit(additional_properties.is_object() ? additional_properties : json::object(), sub_name + "-value");
std::string kv_rule = _add_rule(sub_name + "-kv", _add_rule("string", PRIMITIVE_RULES.at("string")) + " \":\" space " + value_rule);
prop_kv_rule_names["*"] = kv_rule;
optional_props.push_back("*");
}
std::string rule = "\"{\" space ";
for (size_t i = 0; i < required_props.size(); i++) {
if (i > 0) {
rule += " \",\" space ";
}
rule += prop_kv_rule_names[required_props[i]];
}
if (!optional_props.empty()) {
rule += " (";
if (!required_props.empty()) {
rule += " \",\" space ( ";
}
std::function<std::string(const std::vector<std::string> &, bool)> get_recursive_refs = [&](const std::vector<std::string> & ks, bool first_is_optional) {
std::string res;
if (ks.empty()) {
return res;
}
std::string k = ks[0];
std::string kv_rule_name = prop_kv_rule_names[k];
if (k == "*") {
res = _add_rule(
name + (name.empty() ? "" : "-") + "additional-kvs",
kv_rule_name + " ( \",\" space " + kv_rule_name + " )*"
);
} else if (first_is_optional) {
res = "( \",\" space " + kv_rule_name + " )?";
} else {
res = kv_rule_name;
}
if (ks.size() > 1) {
res += " " + _add_rule(
name + (name.empty() ? "" : "-") + k + "-rest",
get_recursive_refs(std::vector<std::string>(ks.begin() + 1, ks.end()), true)
);
}
return res;
};
for (size_t i = 0; i < optional_props.size(); i++) {
if (i > 0) {
rule += " | ";
}
rule += get_recursive_refs(std::vector<std::string>(optional_props.begin() + i, optional_props.end()), false);
}
if (!required_props.empty()) {
rule += " )";
}
rule += " )?";
}
rule += " \"}\" space";
return rule;
}
public:
SchemaConverter(
const std::function<json(const std::string &)> & fetch_json,
bool dotall)
: _fetch_json(fetch_json), _dotall(dotall)
{
_rules["space"] = SPACE_RULE;
}
void resolve_refs(nlohmann::json & schema, const std::string & url) {
/*
* Resolves all $ref fields in the given schema, fetching any remote schemas,
* replacing each $ref with absolute reference URL and populates _refs with the
* respective referenced (sub)schema dictionaries.
*/
std::function<void(json &)> visit_refs = [&](json & n) {
if (n.is_array()) {
for (auto & x : n) {
visit_refs(x);
}
} else if (n.is_object()) {
if (n.contains("$ref")) {
std::string ref = n["$ref"];
if (_refs.find(ref) == _refs.end()) {
json target;
if (ref.find("https://") == 0) {
std::string base_url = ref.substr(0, ref.find('#'));
auto it = _refs.find(base_url);
if (it != _refs.end()) {
target = it->second;
} else {
// Fetch the referenced schema and resolve its refs
auto referenced = _fetch_json(ref);
resolve_refs(referenced, base_url);
_refs[base_url] = referenced;
}
if (ref.find('#') == std::string::npos || ref.substr(ref.find('#') + 1).empty()) {
return;
}
} else if (ref.find("#/") == 0) {
target = schema;
n["$ref"] = url + ref;
ref = url + ref;
} else {
_errors.push_back("Unsupported ref: " + ref);
return;
}
std::string pointer = ref.substr(ref.find('#') + 1);
std::vector<std::string> tokens = split(pointer, "/");
for (size_t i = 1; i < tokens.size(); ++i) {
std::string sel = tokens[i];
if (target.is_null() || !target.contains(sel)) {
_errors.push_back("Error resolving ref " + ref + ": " + sel + " not in " + target.dump());
return;
}
target = target[sel];
}
_refs[ref] = target;
}
} else {
for (auto & kv : n.items()) {
visit_refs(kv.value());
}
}
}
};
visit_refs(schema);
}
std::string _generate_constant_rule(const json & value) {
if (!value.is_string()) {
_errors.push_back("Only std::string constants are supported, got " + value.dump());
return "";
}
return format_literal(value.get<std::string>());
}
std::string visit(const json & schema, const std::string & name) {
json schema_type = schema.contains("type") ? schema["type"] : json();
std::string schema_format = schema.contains("format") ? schema["format"].get<std::string>() : "";
std::string rule_name = is_reserved_name(name) ? name + "-" : name.empty() ? "root" : name;
if (schema.contains("$ref")) {
return _add_rule(rule_name, _resolve_ref(schema["$ref"]));
} else if (schema.contains("oneOf") || schema.contains("anyOf")) {
std::vector<json> alt_schemas = schema.contains("oneOf") ? schema["oneOf"].get<std::vector<json>>() : schema["anyOf"].get<std::vector<json>>();
return _add_rule(rule_name, _generate_union_rule(name, alt_schemas));
} else if (schema_type.is_array()) {
std::vector<json> schema_types;
for (const auto & t : schema_type) {
schema_types.push_back({{"type", t}});
}
return _add_rule(rule_name, _generate_union_rule(name, schema_types));
} else if (schema.contains("const")) {
return _add_rule(rule_name, _generate_constant_rule(schema["const"]));
} else if (schema.contains("enum")) {
std::vector<std::string> enum_values;
for (const auto & v : schema["enum"]) {
enum_values.push_back(_generate_constant_rule(v));
}
return _add_rule(rule_name, join(enum_values.begin(), enum_values.end(), " | "));
} else if ((schema_type.is_null() || schema_type == "object")
&& (schema.contains("properties") ||
(schema.contains("additionalProperties") && schema["additionalProperties"] != true))) {
std::unordered_set<std::string> required;
if (schema.contains("required") && schema["required"].is_array()) {
for (const auto & item : schema["required"]) {
if (item.is_string()) {
required.insert(item.get<std::string>());
}
}
}
std::vector<std::pair<std::string, json>> properties;
if (schema.contains("properties")) {
for (const auto & prop : schema["properties"].items()) {
properties.emplace_back(prop.key(), prop.value());
}
}
return _add_rule(rule_name,
_build_object_rule(
properties, required, name,
schema.contains("additionalProperties") ? schema["additionalProperties"] : json()));
} else if ((schema_type.is_null() || schema_type == "object") && schema.contains("allOf")) {
std::unordered_set<std::string> required;
std::vector<std::pair<std::string, json>> properties;
std::string hybrid_name = name;
std::function<void(const json &, bool)> add_component = [&](const json & comp_schema, bool is_required) {
if (comp_schema.contains("$ref")) {
add_component(_refs[comp_schema["$ref"]], is_required);
} else if (comp_schema.contains("properties")) {
for (const auto & prop : comp_schema["properties"].items()) {
properties.emplace_back(prop.key(), prop.value());
if (is_required) {
required.insert(prop.key());
}
}
} else {
// todo warning
}
};
for (auto & t : schema["allOf"]) {
if (t.contains("anyOf")) {
for (auto & tt : t["anyOf"]) {
add_component(tt, false);
}
} else {
add_component(t, true);
}
}
return _add_rule(rule_name, _build_object_rule(properties, required, hybrid_name, json()));
} else if ((schema_type.is_null() || schema_type == "array") && (schema.contains("items") || schema.contains("prefixItems"))) {
json items = schema.contains("items") ? schema["items"] : schema["prefixItems"];
if (items.is_array()) {
std::string rule = "\"[\" space ";
for (size_t i = 0; i < items.size(); i++) {
if (i > 0) {
rule += " \",\" space ";
}
rule += visit(items[i], name + (name.empty() ? "" : "-") + "tuple-" + std::to_string(i));
}
rule += " \"]\" space";
return _add_rule(rule_name, rule);
} else {
std::string item_rule_name = visit(items, name + (name.empty() ? "" : "-") + "item");
std::string list_item_operator = "( \",\" space " + item_rule_name + " )";
std::string successive_items;
int min_items = schema.contains("minItems") ? schema["minItems"].get<int>() : 0;
json max_items_json = schema.contains("maxItems") ? schema["maxItems"] : json();
int max_items = max_items_json.is_number_integer() ? max_items_json.get<int>() : -1;
if (min_items > 0) {
successive_items += repeat(list_item_operator, min_items - 1);
min_items--;
}
if (max_items >= 0 && max_items > min_items) {
successive_items += repeat(list_item_operator + "?", max_items - min_items - 1);
} else {
successive_items += list_item_operator + "*";
}
std::string rule;
if (min_items == 0) {
rule = "\"[\" space ( " + item_rule_name + " " + successive_items + " )? \"]\" space";
} else {
rule = "\"[\" space " + item_rule_name + " " + successive_items + " \"]\" space";
}
return _add_rule(rule_name, rule);
}
} else if ((schema_type.is_null() || schema_type == "string") && schema.contains("pattern")) {
return _visit_pattern(schema["pattern"], rule_name);
} else if ((schema_type.is_null() || schema_type == "string") && std::regex_match(schema_format, std::regex("^uuid[1-5]?$"))) {
return _add_rule(rule_name == "root" ? "root" : schema_format, PRIMITIVE_RULES.at("uuid"));
} else if ((schema_type.is_null() || schema_type == "string") && DATE_RULES.find(schema_format) != DATE_RULES.end()) {
for (const auto & kv : DATE_RULES) {
_add_rule(kv.first, kv.second);
}
return schema_format + "-string";
} else if (schema.empty() || schema_type == "object") {
for (const auto & n : OBJECT_RULE_NAMES) {
_add_rule(n, PRIMITIVE_RULES.at(n));
}
return _add_rule(rule_name, "object");
} else {
if (!schema_type.is_string() || PRIMITIVE_RULES.find(schema_type.get<std::string>()) == PRIMITIVE_RULES.end()) {
_errors.push_back("Unrecognized schema: " + schema.dump());
return "";
}
// TODO: support minimum, maximum, exclusiveMinimum, exclusiveMaximum at least for zero
return _add_rule(rule_name == "root" ? "root" : schema_type.get<std::string>(), PRIMITIVE_RULES.at(schema_type.get<std::string>()));
}
}
void check_errors() {
if (!_errors.empty()) {
throw std::runtime_error("JSON schema conversion failed:\n" + join(_errors.begin(), _errors.end(), "\n"));
}
if (!_warnings.empty()) {
fprintf(stderr, "WARNING: JSON schema conversion was incomplete: %s\n", join(_warnings.begin(), _warnings.end(), "; ").c_str());
}
}
std::string format_grammar() {
std::stringstream ss;
for (const auto & kv : _rules) {
ss << kv.first << " ::= " << kv.second << std::endl;
}
return ss.str();
}
};
std::string json_schema_to_grammar(const json & schema) {
SchemaConverter converter([](const std::string &) { return json::object(); }, /* dotall= */ false);
auto copy = schema;
converter.resolve_refs(copy, "input");
converter.visit(copy, "");
converter.check_errors();
return converter.format_grammar();
}