rawsql-ts
Version:
[beta]High-performance SQL parser and AST analyzer written in TypeScript. Provides fast parsing and advanced transformation capabilities.
57 lines • 2.72 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.WindowClauseParser = void 0;
const Clause_1 = require("../models/Clause");
const Lexeme_1 = require("../models/Lexeme");
const SqlTokenizer_1 = require("./SqlTokenizer");
const WindowExpressionParser_1 = require("./WindowExpressionParser");
class WindowClauseParser {
// Parse SQL string to AST (was: parse)
static parse(query) {
const tokenizer = new SqlTokenizer_1.SqlTokenizer(query);
const lexemes = tokenizer.readLexmes();
const result = this.parseFromLexeme(lexemes, 0);
if (result.newIndex < lexemes.length) {
throw new Error(`Syntax error: Unexpected token "${lexemes[result.newIndex].value}" at position ${result.newIndex}. The WINDOW clause is complete but there are additional tokens.`);
}
return result.value;
}
// Parse from lexeme array (was: parse)
static parseFromLexeme(lexemes, index) {
let idx = index;
if (lexemes[idx].value !== 'window') {
throw new Error(`Syntax error at position ${idx}: Expected 'WINDOW' keyword but found "${lexemes[idx].value}". WINDOW clauses must start with the WINDOW keyword.`);
}
idx++;
if (idx >= lexemes.length) {
throw new Error(`Syntax error: Unexpected end of input after 'WINDOW' keyword. The WINDOW clause requires at least one window definition.`);
}
const windows = [];
while (idx < lexemes.length) {
if (idx >= lexemes.length || lexemes[idx].type !== Lexeme_1.TokenType.Identifier) {
throw new Error(`Syntax error: Expected window name after 'WINDOW' keyword.`);
}
const name = lexemes[idx].value;
idx++;
if (idx >= lexemes.length || lexemes[idx].value !== 'as') {
throw new Error(`Syntax error at position ${idx}: Expected 'AS' keyword after window name.`);
}
idx++;
const expr = WindowExpressionParser_1.WindowExpressionParser.parseFromLexeme(lexemes, idx);
idx = expr.newIndex;
windows.push(new Clause_1.WindowFrameClause(name, expr.value));
if (idx < lexemes.length && lexemes[idx].type & Lexeme_1.TokenType.Comma) {
idx++;
}
else {
break;
}
}
if (windows.length === 0) {
throw new Error('At least one WINDOW clause is required after WINDOW keyword.');
}
return { value: new Clause_1.WindowsClause(windows), newIndex: idx };
}
}
exports.WindowClauseParser = WindowClauseParser;
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