Function intersection

core/util/ranges.ts:27–58

(a: Range, b: Range)

}

export function intersection(a: Range, b: Range): Range | null {
  const startLine = Math.max(a.start.line, b.start.line);
  const endLine = Math.min(a.end.line, b.end.line);

  if (startLine > endLine) {
    return null;
  }

  if (startLine === endLine) {
    const startCharacter = Math.max(a.start.character, b.start.character);
    const endCharacter = Math.min(a.end.character, b.end.character);

    if (startCharacter > endCharacter) {
      return null;
    }

    return {
      start: { line: startLine, character: startCharacter },
      end: { line: endLine, character: endCharacter },
    };
  }

  const startCharacter =
    startLine === a.start.line ? a.start.character : b.start.character;
  const endCharacter =
    endLine === a.end.line ? a.end.character : b.end.character;

  return {
    start: { line: startLine, character: startCharacter },
    end: { line: endLine, character: endCharacter },
  };
}

export function union(a: Range, b: Range): Range {
  let start: Position;