grammars: x{min,max} repetition operator (#6640)

* grammars: x{min,max} repetition operator + tweak +/*/? to avoid duplication of original over alternates

* grammars: handle `x{n}` and fix `x{n,n}`

* grammars: document new repetition operators

* grammars: uniform use of int for min & max

* grammars: refactor parser test

* grammar: parsing tests w/ natural pretty print of updated expectations

* grammars: much prettier print of expectations (+ TEST_GRAMMAR_PARSER_PRINT_ALL=1 to force all)

* grammars: improve test pretty print again

* grammars: pretty print rules and chars

* grammars: fix copy rule skipping

* grammars: disallow `a{,}` (not allowed in regexps)

* Update common/grammar-parser.cpp

Co-authored-by: Clint Herron <hanclinto@gmail.com>

* grammars: fix copy rule skipping (again) & display of expectations

* grammars: more test cases

* grammars: update reps parsing to bring ? / * / + closer to before

* json: use new GBNF repetitions{m,n} syntax

* grammars: update performance gotchas w/ repetition advice

* Update examples/json_schema_to_grammar.py

Co-authored-by: Clint Herron <hanclinto@gmail.com>

* Update examples/server/public/json-schema-to-grammar.mjs

Co-authored-by: Clint Herron <hanclinto@gmail.com>

* grammars: comment on rule repetitions

* grammars: ensure unambiguous number alternatives

* grammar: nit typo switched error msgs

* grammar: nit numbering in comment

* json: update numeric rule to be unambiguous

* Apply suggestions from code review

Co-authored-by: Clint Herron <hanclinto@gmail.com>

* Update examples/server/public/json-schema-to-grammar.mjs

Co-authored-by: Clint Herron <hanclinto@gmail.com>

* json: fix integral-part

* grammar: add repetition tests

---------

Co-authored-by: Clint Herron <hanclinto@gmail.com>
This commit is contained in:
Olivier Chafik 2024-06-06 10:07:06 +01:00 committed by GitHub
parent f5d7b268ec
commit 55b2d0849d
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GPG key ID: B5690EEEBB952194
9 changed files with 736 additions and 418 deletions

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@ -16,58 +16,27 @@ static std::string join(Iterator begin, Iterator end, const std::string & separa
static std::string repeat(const std::string & str, size_t n);
static std::string build_repetition(const std::string & item_rule, int min_items, int max_items, const std::string & separator_rule = "", bool item_rule_is_literal = false) {
static std::string build_repetition(const std::string & item_rule, int min_items, int max_items, const std::string & separator_rule = "") {
auto has_max = max_items != std::numeric_limits<int>::max();
if (min_items == 0 && max_items == 1) {
return item_rule + "?";
}
if (separator_rule.empty()) {
if (min_items == 0 && max_items == 1) {
return item_rule + "?";
} else if (min_items == 1 && max_items == std::numeric_limits<int>::max()) {
if (min_items == 1 && !has_max) {
return item_rule + "+";
}
}
std::string result;
if (min_items > 0) {
if (item_rule_is_literal && separator_rule.empty()) {
result = "\"" + repeat(std::string(item_rule.begin() + 1, item_rule.end() - 1), min_items) + "\"";
} else if (min_items == 0 && !has_max) {
return item_rule + "*";
} else {
std::vector<std::string> items(min_items, item_rule);
result = join(items.begin(), items.end(), separator_rule.empty() ? " " : " " + separator_rule + " ");
return item_rule + "{" + std::to_string(min_items) + "," + (has_max ? std::to_string(max_items) : "") + "}";
}
}
std::function<std::string(int, bool)> opt_repetitions = [&](int up_to_n, bool prefix_with_sep) -> std::string {
auto content = prefix_with_sep && !separator_rule.empty() ? separator_rule + " " + item_rule : item_rule;
if (up_to_n == 0) {
return "";
} else if (up_to_n == 1) {
return "(" + content + ")?";
} else if (!separator_rule.empty() && !prefix_with_sep) {
return "(" + content + " " + opt_repetitions(up_to_n - 1, true) + ")?";
} else {
std::string res = repeat("(" + content + " ", up_to_n);
// strip trailing space
res = res.substr(0, res.length() - 1);
res += repeat(")?", up_to_n);
return res;
}
};
if (min_items > 0 && max_items != min_items) {
result += " ";
auto result = item_rule + " " + build_repetition("(" + separator_rule + " " + item_rule + ")", min_items == 0 ? 0 : min_items - 1, has_max ? max_items - 1 : max_items);
if (min_items == 0) {
result = "(" + result + ")?";
}
if (max_items != std::numeric_limits<int>::max()) {
result += opt_repetitions(max_items - min_items, min_items > 0);
} else {
std::string item_operator = "(" + (separator_rule.empty() ? "" : separator_rule + " ") + item_rule + ")";
if (min_items == 0 && !separator_rule.empty()) {
result = "(" + item_rule + " " + item_operator + "*)?";
} else {
result += item_operator + "*";
}
}
return result;
}
@ -78,30 +47,24 @@ struct BuiltinRule {
std::vector<std::string> deps;
};
const std::string _up_to_15_digits = build_repetition("[0-9]", 0, 15);
std::unordered_map<std::string, BuiltinRule> PRIMITIVE_RULES = {
{"boolean", {"(\"true\" | \"false\") space", {}}},
{"decimal-part", {"[0-9] " + _up_to_15_digits, {}}},
{"integral-part", {"[0-9] | [1-9] " + _up_to_15_digits, {}}},
{"decimal-part", {"[0-9]{1,16}", {}}},
{"integral-part", {"[0] | [1-9] [0-9]{0,15}", {}}},
{"number", {"(\"-\"? integral-part) (\".\" decimal-part)? ([eE] [-+]? integral-part)? space", {"integral-part", "decimal-part"}}},
{"integer", {"(\"-\"? integral-part) space", {"integral-part"}}},
{"value", {"object | array | string | number | boolean | null", {"object", "array", "string", "number", "boolean", "null"}}},
{"object", {"\"{\" space ( string \":\" space value (\",\" space string \":\" space value)* )? \"}\" space", {"string", "value"}}},
{"array", {"\"[\" space ( value (\",\" space value)* )? \"]\" space", {"value"}}},
{"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", {}}},
{"char", {"[^\"\\\\] | \"\\\\\" ([\"\\\\/bfnrt] | \"u\" [0-9a-fA-F] [0-9a-fA-F] [0-9a-fA-F] [0-9a-fA-F])", {}}},
{"uuid", {"\"\\\"\" [0-9a-fA-F]{8} \"-\" [0-9a-fA-F]{4} \"-\" [0-9a-fA-F]{4} \"-\" [0-9a-fA-F]{4} \"-\" [0-9a-fA-F]{12} \"\\\"\" space", {}}},
{"char", {"[^\"\\\\] | \"\\\\\" ([\"\\\\/bfnrt] | \"u\" [0-9a-fA-F]{4})", {}}},
{"string", {"\"\\\"\" char* \"\\\"\" space", {"char"}}},
{"null", {"\"null\" space", {}}},
};
std::unordered_map<std::string, BuiltinRule> STRING_FORMAT_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", {"[0-9]{4} \"-\" ( \"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]{3} )? ( \"Z\" | ( \"+\" | \"-\" ) ( [01] [0-9] | \"2\" [0-3] ) \":\" [0-5] [0-9] )", {}}},
{"date-time", {"date \"T\" time", {"date", "time"}}},
{"date-string", {"\"\\\"\" date \"\\\"\" space", {"date"}}},
{"time-string", {"\"\\\"\" time \"\\\"\" space", {"time"}}},
@ -385,8 +348,7 @@ private:
sub_is_literal ? "\"" + sub + "\"" : sub,
min_times,
max_times,
"",
sub_is_literal
""
);
seq.back().second = false;
} else {