ExpressionParser constructor

Implementation

ExpressionParser() {
  expression.set(binaryExpression.seq(conditionArguments.optional()).map(
      (l) => l[1] == null
          ? l[0]
          : ConditionalExpression(l[0], l[1][0], l[1][1])));
  token.set((literal | unaryExpression | variable).cast<Expression>());
}