public Comparison Parse(ILexer lexer, IExpressionParser expressionParser, IWasmicSyntaxTreeExpression lhs)
{
ComparisonOperator op;
switch (lexer.Next.TokenType)
{
case TokenType.EqualComparer: op = ComparisonOperator.Equals; break;
case TokenType.GrThanComparer: op = ComparisonOperator.GreaterThan; break;
case TokenType.GrThanOrEqComparer: op = ComparisonOperator.GreaterThanOrEqual; break;
case TokenType.LsThanComparer: op = ComparisonOperator.LessThan; break;
case TokenType.LsThanOrEqComparer: op = ComparisonOperator.LessThanOrEqual; break;
default:
throw new WasmicCompilerException(
$"expected comparison operator, found {lexer.Next.TokenType}"
);
}
lexer.Advance(); // eat comparison
var rhs = expressionParser.GetExpression();
return(new Comparison(lhs, rhs, op));
}
public BinopExpresison Parse(ILexer lexer, IExpressionParser expressionParser, IWasmicSyntaxTreeExpression lhs)
{
Operation operation;
switch (lexer.Next.TokenType)
{
case TokenType.Plus:
operation = Operation.Add;
break;
case TokenType.Minus:
operation = Operation.Subtract;
break;
case TokenType.Star:
operation = Operation.Multiply;
break;
case TokenType.Slash:
operation = Operation.Divide;
break;
default:
throw new WasmicCompilerException($"{lexer.Next.TokenType} is not binop");
}
lexer.Advance(); // eat operand
var rhs = expressionParser.GetExpression();
return(new BinopExpresison(lhs, rhs, operation));
}
public FunctionCall Parse(
ILexer lexer,
IModuleFunctionMap functionMap,
IExpressionParser expressionParser,
string name)
{
if (functionMap.Contains(name) == false)
{
throw new WasmicCompilerException($"function {name} is not declared");
}
var callFunc = functionMap.Get(name);
var parameters = new List <IWasmicSyntaxTreeExpression>();
lexer.AssertNext(TokenType.L_Paren);
lexer.Advance();
if (lexer.Next.TokenType != TokenType.R_Paren)
{
do
{
var parameterLoad = expressionParser.GetExpression();
parameters.Add(parameterLoad);
} while(lexer.Next.TokenType == TokenType.Comma);
}
lexer.AssertNext(TokenType.R_Paren);
lexer.Advance();
var expectedParameters = callFunc.Parameters;
if (expectedParameters.Count != parameters.Count)
{
throw new WasmicCompilerException($"unmatched argument count");
}
for (int i = 0; i < expectedParameters.Count; i++)
{
if (expectedParameters[i].Type != parameters[i].Type)
{
throw new WasmicCompilerException($"expected argument to be {expectedParameters[i].Type} but found {parameters[i].Type}");
}
}
return(new FunctionCall(name, callFunc.ReturnType?.Type, parameters));
}