public override Expression Resolve()
{
for (int i = 0; i < this.Expressions.Length; ++i)
{
this.Expressions[i] = this.Expressions[i].Resolve();
}
for (int i = 1; i < this.Expressions.Length - 1; ++i)
{
if (!this.IsSimpleEnough(this.Expressions[i]))
{
throw new ParserException(this.Expressions[i].FirstToken,
"Complex expressions are not allowed as the inner elements of comparison chains. " +
"This is because this expression must be expanded from e.g. a < b < c to a < b && b < c, " +
"thus causing inner elements to be invoked multiple times.");
}
}
List<Expression> output = new List<Expression>();
for (int i = 0; i < this.Expressions.Length - 1; ++i)
{
Expression left = this.Expressions[i];
Expression right = this.Expressions[i + 1];
Expression single = new BinaryOpChain(new Expression[] { left, right }, new Token[] { this.OpTokens[i] });
output.Add(single);
}
if (output.Count == 1) return output[0];
List<Token> andTokens = new List<Token>();
while (andTokens.Count < output.Count - 1)
{
andTokens.Add(new Token("and", null, 0, 0, TokenType.ALPHANUM));
}
return new BinaryOpChain(output, andTokens);
}
private ForLoop ResolveWithRange(Expression[] rangeArgs)
{
List<Executable> init = new List<Executable>();
Expression increment = new IntegerConstant(null, 1);
if (rangeArgs.Length == 3)
{
if (rangeArgs[2] is IntegerConstant || rangeArgs[2] is Variable)
{
increment = rangeArgs[2];
}
string variableName = "crayon_conversion_step_" + VARIABLE_ALLOCATION_COUNTER++;
init.Add(new Assignment(new Variable(null, variableName), new Token("=", null, 0, 0, TokenType.OTHER), rangeArgs[2]));
increment = new Variable(null, variableName);
}
Expression start = new IntegerConstant(null, 0);
// if 2 or 3 are present, then an explicit start is given
if (rangeArgs.Length > 1)
{
start = rangeArgs[0];
}
Expression end = null;
if (rangeArgs.Length == 1)
{
end = rangeArgs[0];
}
else
{
end = rangeArgs[1];
}
if (end is IntegerConstant || end is Variable)
{
// this is fine
}
else
{
string variableName = "crayon_conversion_length_" + VARIABLE_ALLOCATION_COUNTER++;
init.Add(new Assignment(new Variable(null, variableName), new Token("=", null, 0, 0, TokenType.OTHER), end));
end = new Variable(null, variableName);
}
init.Add(new Assignment(new Variable(this.IteratorVariable, this.IteratorVariable.Value), new Token("=", null, 0, 0, TokenType.OTHER), start));
Expression condition = new BinaryOpChain(
new Expression[] {
new Variable(this.IteratorVariable, this.IteratorVariable.Value),
end },
new Token[] { new Token("<", null, 0, 0, TokenType.OTHER) });
List<Executable> step = new List<Executable>()
{
new Assignment(
new Variable(this.IteratorVariable, this.IteratorVariable.Value),
new Token("+=", null, 0, 0, TokenType.OTHER),
increment)
};
return new ForLoop(this.FirstToken, this, init, condition, step, this.Body);
}
private void SerializeBinaryOpChain(List<string> output, BinaryOpChain opChain)
{
for (int i = 0; i < opChain.Expressions.Length; ++i)
{
if (i > 0)
{
output.Add(" ");
output.Add(opChain.OpTokens[i - 1].Value);
output.Add(" ");
}
SerializeExpression(output, opChain.Expressions[i]);
}
}
