bool Parser::parseIdentifier (Lexer& lexer, string* output)
{
if (lexer.getType () != Lexer::IDENTIFIER)
return this->fail (lexer, "expected column identifier");
*output = lexer.getCurrent ();
lexer.next ();
return true;
}
bool Parser::parseValue (Lexer& lexer, Lookup& lookup, Int32u* slot, const Extractor** output)
{
const Extractor* argument;
Extractors arguments;
const Constant* constant;
const Function* function;
string name;
Float64 number;
switch (lexer.getType ())
{
case Lexer::IDENTIFIER:
name = lexer.getCurrent ();
lexer.next ();
if (lexer.getType () == Lexer::PARENTHESIS_BEGIN)
{
function = 0;
for (Int32u i = 0; Function::functions[i].name; ++i)
{
if (Function::functions[i].name == name)
{
function = &Function::functions[i];
break;
}
}
if (!function)
return this->fail (lexer, string ("unknown function name '") + lexer.getCurrent () + "'");
lexer.next ();
while (lexer.getType () != Lexer::PARENTHESIS_END)
{
if (arguments.size () > 0 && !this->parseType (lexer, Lexer::COMMA, "argument separator"))
return false;
if (!this->parseExpression (lexer, lookup, slot, &argument))
return false;
arguments.push_back (argument);
}
lexer.next ();
if (arguments.size () < function->min || (function->max > 0 && arguments.size () > function->max))
return this->fail (lexer, "wrong number of arguments");
*output = function->builder (arguments, slot);
}
else
{
constant = 0;
for (Int32u i = 0; Constant::constants[i].name; ++i)
{
if (Constant::constants[i].name == name)
{
constant = &Constant::constants[i];
break;
}
}
if (constant)
*output = new ConstantExtractor (constant->value);
else
*output = new FieldExtractor (lookup.store (name));
}
break;
case Lexer::NUMBER:
if (!Convert::toFloat (&number, lexer.getCurrent ().data (), lexer.getCurrent ().length ()))
return this->fail (lexer, "invalid number");
*output = new ConstantExtractor (Variant (number));
lexer.next ();
break;
case Lexer::STRING:
*output = new ConstantExtractor (Variant (lexer.getCurrent ()));
lexer.next ();
break;
default:
this->fail (lexer, "unexpected character");
return false;
}
this->extractors.push_back (*output);
return true;
}
