# Class: LexemeCursor

Defined in: packages/core/src/utils/LexemeCursor.ts:25

Utility class for cursor-to-lexeme mapping in SQL text.

Provides functionality to find lexemes at specific cursor positions for IDE integration. Handles SQL parsing with proper comment and whitespace handling for editor features.

Example

const sql = "SELECT id FROM users WHERE active = true";
const lexeme = LexemeCursor.findLexemeAtPosition(sql, 7); // position at 'id'
console.log(lexeme?.value); // 'id'

Constructors

Constructor

new LexemeCursor(): LexemeCursor

Returns

LexemeCursor

Methods

findLexemeAtLineColumn()

static findLexemeAtLineColumn(sql, position): null | Lexeme

Defined in: packages/core/src/utils/LexemeCursor.ts:48

Find the lexeme at the specified line and column position.

Designed for GUI editor integration where users select alias text. Uses 1-based line and column indexing to match editor conventions.

Parameters

sql

string

The SQL string to analyze

position

LineColumn

Line and column position (1-based)

Returns

null | Lexeme

The lexeme at the position, or null if not found

Example

const sql = "SELECT user_id FROM orders";
const lexeme = LexemeCursor.findLexemeAtLineColumn(sql, { line: 1, column: 8 });
console.log(lexeme?.value); // 'user_id'

---

findLexemeAtPosition()

static findLexemeAtPosition(sql, cursorPosition): null | Lexeme

Defined in: packages/core/src/utils/LexemeCursor.ts:73

Find the lexeme at the specified cursor position.

Performs intelligent SQL parsing with proper comment and whitespace handling. Returns null if cursor is in whitespace or comments.

Parameters

sql

string

The SQL string to analyze

cursorPosition

number

The cursor position (0-based character offset)

Returns

null | Lexeme

The lexeme at the position, or null if not found

Example

const sql = "SELECT user_id FROM orders";
const lexeme = LexemeCursor.findLexemeAtPosition(sql, 7);
console.log(lexeme?.value); // 'user_id'

---

getAllLexemesWithPosition()

static getAllLexemesWithPosition(sql): Lexeme[]

Defined in: packages/core/src/utils/LexemeCursor.ts:107

Get all lexemes with position information from SQL text.

Tokenizes the entire SQL string with precise position information. Useful for syntax highlighting, code analysis, and editor features.

Parameters

sql

string

The SQL string to tokenize

Returns

Lexeme[]

Array of lexemes with position information (excludes comments/whitespace)

Example

const sql = "SELECT id FROM users";
const lexemes = LexemeCursor.getAllLexemesWithPosition(sql);
lexemes.forEach(l => console.log(`${l.value} at ${l.position.startPosition}`));

---

charOffsetToLineColumn()

static charOffsetToLineColumn(sql, charOffset): null | LineColumn

Defined in: packages/core/src/utils/LexemeCursor.ts:323

Convert character offset to line and column position.

Parameters

sql

string

The SQL string

charOffset

number

Character offset (0-based)

Returns

null | LineColumn

Line and column position (1-based), or null if offset is out of bounds