private AstItem ReadSingleAstItem(TokenIterator tokens)
{
AstItem result;
var token = tokens.Current();
if (token.Kind == TokenKind.Word)
{
var next = tokens.Next();
if (next != null)
{
if (next.Kind == TokenKind.RoundBracketOpen)
{
var dataType = DataType.FindByName(token.Value);
if (dataType != null && dataType.IsVector)
{
//Vector construction with specific vector type name, i.e. "vec4f(...)"
result = ReadVector(tokens);
tokens.StepBack();
}
else
{
result = ReadFuncCall(tokens);
tokens.StepBack();
}
}
else if (next.Kind == TokenKind.SquareBracketOpen)
{
result = ReadIndexAccess(tokens);
tokens.StepBack();
}
else
{
//Not sure what identifier is here. Could be type name, variable etc. Will be specified in next steps.
result = AstItem.AsIdentifier(token.Value);
}
}
else
{
//Not sure what identifier is here. Could be type name, variable etc. Will be specified in next steps.
result = AstItem.AsIdentifier(token.Value);
}
}
else if (token.Kind == TokenKind.VectorConstructor)
{
//Vector construction with the generic "vec(...)"
result = ReadVector(tokens);
tokens.StepBack();
}
else if (token.Kind == TokenKind.Number)
{
result = AstItem.Immediate(token.Value);
}
else if (token.Kind == TokenKind.True || token.Kind == TokenKind.False)
{
result = AstItem.Immediate(DataType.BOOL, token.Value);
}
else if (token.Kind == TokenKind.Char)
{
result = AstItem.Immediate(DataType.CHAR8, token.Value);
}
else if (token.Kind == TokenKind.String)
{
result = AstItem.Immediate(DataType.STRING8, token.Value);
}
else if (token.Kind == TokenKind.SquareBracketOpen)
{
result = AstItem.NewStackArray(ReadArray(tokens));
}
else
{
throw new Exception("Unexpected token type in expression: " + token);
}
return(result);
}