rawsql-ts
Version:
[beta]High-performance SQL parser and AST analyzer written in TypeScript. Provides fast parsing and advanced transformation capabilities.
59 lines • 2.31 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.TypeTokenReader = void 0;
const BaseTokenReader_1 = require("./BaseTokenReader");
const Lexeme_1 = require("../models/Lexeme");
const stringUtils_1 = require("../utils/stringUtils");
const KeywordTrie_1 = require("../models/KeywordTrie");
const KeywordParser_1 = require("../parsers/KeywordParser");
// Use KeywordTrie to identify type names composed of multiple words.
const trie = new KeywordTrie_1.KeywordTrie([
// type
["double", "precision"],
["character", "varying"],
["time", "without", "time", "zone"],
["time", "with", "time", "zone"],
["timestamp", "without", "time", "zone"],
["timestamp", "with", "time", "zone"],
]);
const typeParser = new KeywordParser_1.KeywordParser(trie);
/**
* Reads SQL identifier tokens
*/
class TypeTokenReader extends BaseTokenReader_1.BaseTokenReader {
/**
* Try to read an identifier token
*/
tryRead(previous) {
if (this.isEndOfInput()) {
return null;
}
// Check for keyword identifiers
const keyword = typeParser.parse(this.input, this.position);
if (keyword !== null) {
this.position = keyword.newPosition;
return this.createLexeme(Lexeme_1.TokenType.Type, keyword.keyword);
}
// check pervious token
if (previous === null) {
return null;
}
const result = stringUtils_1.StringUtils.tryReadRegularIdentifier(this.input, this.position);
if (!result) {
return null;
}
this.position = result.newPosition;
// type cast command
if (previous.type & Lexeme_1.TokenType.Command && previous.value === "as") {
// If the previous token is the `as` keyword, it could be a type cast or an identifier
return this.createLexeme(Lexeme_1.TokenType.Identifier | Lexeme_1.TokenType.Type, result.identifier);
}
// postgres type conversion
if (previous.type & Lexeme_1.TokenType.Operator && previous.value === "::") {
return this.createLexeme(Lexeme_1.TokenType.Type, result.identifier);
}
return null;
}
}
exports.TypeTokenReader = TypeTokenReader;
//# sourceMappingURL=TypeTokenReader.js.map