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rawsql-ts

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[beta]High-performance SQL parser and AST analyzer written in TypeScript. Provides fast parsing and advanced transformation capabilities.

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import { NullsSortDirection, OrderByClause, OrderByItem, SortDirection } from "../models/Clause"; import { TokenType } from "../models/Lexeme"; import { SqlTokenizer } from "./SqlTokenizer"; import { ValueParser } from "./ValueParser"; export class OrderByClauseParser { // Parse SQL string to AST (was: parse) static parse(query) { const tokenizer = new SqlTokenizer(query); // Initialize tokenizer const lexemes = tokenizer.readLexmes(); // Get tokens // Parse const result = this.parseFromLexeme(lexemes, 0); // Error if there are remaining tokens if (result.newIndex < lexemes.length) { throw new Error(`Syntax error: Unexpected token "${lexemes[result.newIndex].value}" at position ${result.newIndex}. The ORDER BY 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 !== 'order by') { throw new Error(`Syntax error at position ${idx}: Expected 'ORDER BY' keyword but found "${lexemes[idx].value}". ORDER BY clauses must start with the ORDER BY keywords.`); } idx++; const items = []; const item = this.parseItem(lexemes, idx); items.push(item.value); idx = item.newIndex; while (idx < lexemes.length && (lexemes[idx].type & TokenType.Comma)) { idx++; const item = this.parseItem(lexemes, idx); items.push(item.value); idx = item.newIndex; } if (items.length === 0) { throw new Error(`Syntax error at position ${index}: No ordering expressions found. The ORDER BY clause requires at least one expression to order by.`); } else { const clause = new OrderByClause(items); return { value: clause, newIndex: idx }; } } static parseItem(lexemes, index) { let idx = index; const parsedValue = ValueParser.parseFromLexeme(lexemes, idx); const value = parsedValue.value; idx = parsedValue.newIndex; if (idx >= lexemes.length) { return { value: value, newIndex: idx }; } // asc, desc const sortDirection = idx >= lexemes.length ? null : lexemes[idx].value === 'asc' ? (idx++, SortDirection.Ascending) : lexemes[idx].value === 'desc' ? (idx++, SortDirection.Descending) : null; // nulls first, nulls last const nullsSortDirection = idx >= lexemes.length ? null : lexemes[idx].value === 'nulls first' ? (idx++, NullsSortDirection.First) : lexemes[idx].value === 'nulls last' ? (idx++, NullsSortDirection.Last) : null; if (sortDirection === null && nullsSortDirection === null) { return { value: value, newIndex: idx }; } return { value: new OrderByItem(value, sortDirection, nullsSortDirection), newIndex: idx }; } } //# sourceMappingURL=OrderByClauseParser.js.map