src/less/parse.js
function checkInterpolatedVariable(i) {
  const start = i;
  let l;

  if (i >= tokensLength) return 0;

  if (tokens[i].type !== TokenType.CommercialAt ||
      !tokens[i + 1] || tokens[i + 1].type !== TokenType.LeftCurlyBracket) {
    return 0;
  }

  i += 2;

  if (l = checkIdent(i)) i += l;
  else return 0;

  return tokens[i].type === TokenType.RightCurlyBracket ? i - start + 1 : 0;
}
function checkInterpolatedVariable(i) {
  const start = i;
  let l;

  if (i >= tokensLength) return 0;

  if (tokens[i].type !== TokenType.CommercialAt ||
      !tokens[i + 1] || tokens[i + 1].type !== TokenType.LeftCurlyBracket) {
    return 0;
  }

  i += 2;

  if (l = checkIdent(i)) i += l;
  else return 0;

  return tokens[i].type === TokenType.RightCurlyBracket ? i - start + 1 : 0;
}
function checkInterpolatedVariable ( i ) { const start = i ; let l ; if ( i >= tokensLength ) return 0 ; if ( tokens [ i ] . type !== TokenType . CommercialAt || ! tokens [ i + 1 ] || tokens [ i + 1 ] . type !== TokenType . LeftCurlyBracket ) { return 0 ; } i += 2 ; if ( l = checkIdent ( i ) ) i += l ; else return 0 ; return tokens [ i ] . type === TokenType . RightCurlyBracket ? i - start + 1 : 0 ; }
Check if token is part of LESS interpolated variable
@param {Number} i Token's index number
@returns {Number}
Check if token is part of LESS interpolated variable