rawsql-ts
Version:
[beta]High-performance SQL parser and AST analyzer written in TypeScript. Provides fast parsing and advanced transformation capabilities.
69 lines • 3.4 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.CommentUtils = void 0;
/**
* Utility functions for handling comments in parsers
*/
class CommentUtils {
/**
* Collects comments from preceding tokens that are associated with a specific keyword.
* This function looks for comments in tokens before the current position that might
* be related to the current clause.
*
* @param lexemes Array of lexemes
* @param currentIndex Index of the current keyword token
* @param keywordValue Expected keyword value (e.g., 'from', 'where')
* @returns Array of comments associated with this clause
*/
static collectClauseComments(lexemes, currentIndex, keywordValue) {
if (currentIndex >= lexemes.length || lexemes[currentIndex].value.toLowerCase() !== keywordValue.toLowerCase()) {
return null;
}
const comments = [];
// Collect comments from the keyword token itself
if (lexemes[currentIndex].comments) {
comments.push(...lexemes[currentIndex].comments);
}
// Look backwards for comments that might be associated with this clause
// We'll look at the previous token to see if it has comments that should belong to this clause
let checkIndex = currentIndex - 1;
while (checkIndex >= 0) {
const prevToken = lexemes[checkIndex];
// If the previous token has comments and it's not a significant SQL token,
// those comments might belong to the current clause
if (prevToken.comments && prevToken.comments.length > 0) {
// Check if the comments contain keywords that suggest they belong to the current clause
const clauseSpecificComments = prevToken.comments.filter(comment => {
const lowerComment = comment.toLowerCase();
return lowerComment.includes(keywordValue.toLowerCase()) ||
lowerComment.includes('の') || // Japanese possessive particle
lowerComment.includes('コメント'); // "comment" in Japanese
});
if (clauseSpecificComments.length > 0) {
comments.unshift(...clauseSpecificComments);
// Remove these comments from the previous token to avoid duplication
prevToken.comments = prevToken.comments.filter(c => !clauseSpecificComments.includes(c));
if (prevToken.comments.length === 0) {
prevToken.comments = null;
}
}
break; // Stop after checking one token with comments
}
// Stop if we encounter another significant SQL keyword
if (this.isSignificantSqlKeyword(prevToken.value)) {
break;
}
checkIndex--;
}
return comments.length > 0 ? comments : null;
}
/**
* Checks if a token value is a significant SQL keyword that would separate clauses
*/
static isSignificantSqlKeyword(value) {
const keywords = new Set(['select', 'from', 'where', 'group by', 'having', 'order by', 'limit', 'offset']);
return keywords.has(value.toLowerCase());
}
}
exports.CommentUtils = CommentUtils;
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