/* Medium to create arguments from the token */
Arg * CreateArg(char *token) {
Arg * newarg;
if (token[0] == '\'') {
newarg = CreateStringLiteral(token);
return newarg;
}
if (isdigit(token[0]) || token[0] == '-') {
newarg = CreateNumericLiteral(token);
return newarg;
}
if (strchr("abcdefghijklmnopqrstuvwxyz_-", tolower(token[0])) == NULL) {
ABORT("Illegal character beginning argument: %s", token);
}
newarg = CreateVarArg(token);
return newarg;
}
ASTExpression* ParseExpr(MemoryArena* arena, Lexer* lex) {
auto parsePrimary = [](MemoryArena* arena, Lexer* lex) -> ASTExpression* {
switch (lex->token.type) {
case TOKEN_TRUE:
{
lex->nextToken();
return CreateIntegerLiteral(arena, 1);
}
case TOKEN_FALSE:
{
lex->nextToken();
return CreateIntegerLiteral(arena, 0);
}
case TOKEN_STRING:
{
auto str = CreateStringLiteral (arena, lex->token.string);
lex->nextToken();
return str;
}
case TOKEN_NUMBER:
{
LOG_VERBOSE("Parsing a numberExpression!");
auto dotPos = lex->token.string.find(".");
bool isFloat = dotPos == std::string::npos ? false : true;
if (isFloat) {
if (lex->token.string.substr(dotPos + 1).find(".") != std::string::npos) {
// ReportError(worker, worker->token.site, "Floating Point value contains two decimal points!");
}
auto value = std::stof(lex->token.string);
auto result = CreateFloatLiteral(arena, value);
lex->nextToken();
return result;
} else {
auto value = std::stoi(lex->token.string);
auto result = CreateIntegerLiteral(arena, value);
lex->nextToken();
return result;
}
}
}
return nullptr;
};
std::function<ASTExpression*(MemoryArena*, Lexer*, ASTExpression*, int)> parseBinary
= [&parsePrimary, &parseBinary](MemoryArena* arena, Lexer* lex, ASTExpression* lhs, int expressionPrec) -> ASTExpression* {
assert(lhs != nullptr);
while (true) {
auto tokenPrec = GetTokenPrecedence(lex->token);
if (tokenPrec < 0) return lhs; // Bail if there is no binop
auto binopToken = lex->token;
lex->nextToken();
// We have a binop lets see what is on the other side!
ASTExpression* rhs = parsePrimary(arena, lex);
if (rhs == nullptr) {
//ReportError(worker, binopToken.site, "Could not parse primary expression to the right of binary opperator '" + binopToken.string + "'");
return nullptr;
}
auto nextPrec = GetTokenPrecedence (lex->token);
if (tokenPrec < nextPrec) {
rhs = parseBinary(arena, lex, rhs, tokenPrec + 1);
if (rhs == nullptr) {
LOG_ERROR("Could not parse recursive rhsParsing!");
return nullptr;
}
}
lhs = (ASTExpression*)CreateBinaryOperation(arena, TokenToOperation(binopToken), lhs, rhs);
} // Goes back to the while loop
};
auto lhs = parsePrimary(arena, lex);
if (lhs == nullptr) return nullptr;
return parseBinary(arena, lex, lhs, 0);
}
