private void SetupOperands(ASTBinary n)
{
//push L
n.Left.Visit(this);
//push R
n.Right.Visit(this);
}
private void TypeCheckEquality(ASTBinary n)
{
CFlatType lhs = CheckSubTree(n.Left);
CFlatType rhs = CheckSubTree(n.Right);
if (lhs.IsSupertype(rhs) || rhs.IsSupertype(lhs))
{
//we're good
_lastSeenType = n.CFlatType = new TypeBool();
}
else
{
//invalid
ReportError(n.Location, "Types '{0}' and '{1}' are not compatible for equality.", TypeToFriendlyName(lhs), TypeToFriendlyName(rhs));
}
}
private void TypeCheckBooleanOperator(ASTBinary n, string errorMessage)
{
bool valid = false;
CFlatType lhs = CheckSubTree(n.Left);
if (lhs is TypeBool)
{
CFlatType rhs = CheckSubTree(n.Right);
if (rhs is TypeBool)
{
_lastSeenType = n.CFlatType = new TypeBool();
valid = true;
}
}
if (!valid)
{
ReportError(n.Location, errorMessage);
}
}
/// <summary>
/// This method looks kinda ugly because I'm using it for all binary operations, which may actually typecheck
/// to different types
/// </summary>
/// <param name="n"></param>
/// <param name="errorMessage"></param>
/// <param name="resultingType">The type that the expression will evaluate as. This is optional, so if you
/// don't pass it in, the compiler will use the supertype of the two operands.
/// </param>
private void TypeCheckNumericBinary(ASTBinary n, string errorMessage, CFlatType resultingType = null)
{
bool valid = false;
CFlatType lhs = CheckSubTree(n.Left);
if (lhs.IsNumeric)
{
CFlatType rhs = CheckSubTree(n.Right);
if (rhs.IsNumeric)
{
//if the parameter was not passed in, we'll figure it out
resultingType = resultingType ?? Supertype(lhs, rhs);
n.CFlatType = resultingType;
_lastSeenType = resultingType;
valid = true;
}
}
if (!valid)
{
ReportError(n.Location, errorMessage);
}
}
public string GetCodeForCommand(IASTNode command, float lineNumber)
{
if (command.Type == ASTNodeType.Command)
{
var cmd = (ASTCommand)command;
switch (cmd.Command)
{
case "PRINT":
return(Target.GetSnippet("commands", "print", "text", GetCodeForExpression(cmd.Operand)));
case "CLS":
return(Target.GetSnippet("commands", "cls"));
case "GOTO":
return(Target.GetSnippet("commands", "goto", "lineNumber", GetCodeForExpression(cmd.Operand)));
case "GOSUB":
return(Target.GetSnippet("commands", "gosub", "lineNumber", GetCodeForExpression(cmd.Operand)));
case "RETURN":
return(Target.GetSnippet("commands", "return"));
case "SLEEP":
return(Target.GetSnippet("commands", "sleep", "time", GetCodeForExpression(cmd.Operand)));
case "LET":
// Operand of LET is a binary expression with =
return(GetCodeForExpression(cmd.Operand));
case "NEXT":
return(GetCodeForNext((ASTVariable)cmd.Operand));
case "TOPOF":
return(GetCodeForTopof((ASTVariable)cmd.Operand));
case "DIM":
return(GetCodeForDim((ASTCall)cmd.Operand));
case "LISTADD":
return(GetCodeForListAdd((ASTCompoundExpression)cmd.Operand));
case "LISTRM":
return(GetCodeForListRm((ASTCompoundExpression)cmd.Operand));
case "LIST":
return(GetCodeForList((ASTVariable)cmd.Operand));
// TODO: PRINTAT
case "INK":
return(Target.GetSnippet("commands", "ink", "colour", GetCodeForExpression(cmd.Operand)));
case "PAPER":
return(Target.GetSnippet("commands", "paper", "colour", GetCodeForExpression(cmd.Operand)));
case "EXIT":
return(Target.GetSnippet("commands", "exit"));
case "STOP":
return(Target.GetSnippet("commands", "stop"));
case "WAITKEY":
return(Target.GetSnippet("commands", "waitkey"));
case "INPUT":
return(GetCodeForInput(cmd.Operand));
case "WRITEFILE":
return(GetCodeForFileWrite(cmd));
case "APPENDFILE":
return(GetCodeForFileWrite(cmd));
default:
return(Croak($@"
Unsupported command ""{cmd.Command}""
It's a valid command, but not yet implemented in the new transpiler.
"));
}
}
if (command.Type == ASTNodeType.If)
{
var ifCmd = (ASTIf)command;
var thenCode = "";
foreach (var thn in ifCmd.Then)
{
thenCode += GetCodeForCommand(thn, lineNumber);
}
var elseCode = "";
if (ifCmd.Else != null)
{
foreach (var els in ifCmd.Else)
{
elseCode += GetCodeForCommand(els, lineNumber);
}
elseCode = Target.GetSnippet("structures", "else", "body", elseCode);
}
return(Target.GetComplexSnippet("structures", "if", new Dictionary <string, string>()
{
{ "condition", GetCodeForExpression(ifCmd.Condition) },
{ "body", thenCode }
}) + elseCode);
}
if (command.Type == ASTNodeType.For)
{
var forLoop = (ASTFor)command;
var loopVar = (ASTVariable)forLoop.Assignment.Left;
var counter = GetCodeForVar(loopVar);
// Bool for skip reassign, not exposed to user code
var forSkip = GetCodeForVar(loopVar, true, false);
var skpDecl = $"{forSkip}_skip";
var skp = Target.GetSnippet("vars", "varAccess", "name", skpDecl);
declarations += Target.GetSnippet("vars", "boolDeclaration", "name", skpDecl);
var startCount = forLoop.Assignment.Right;
var condition = new ASTBinary()
{
Operator = "<=",
Left = loopVar,
Right = forLoop.ToMax
};
var loop = new Loop()
{
Condition = condition,
DefinedOnLine = lineNumber,
SkipVar = skp,
Start = startCount,
Step = forLoop.Step,
Counter = loopVar
};
loops.Add(counter, loop);
return(Target.GetComplexSnippet("loops", "check", new Dictionary <string, string>()
{
{ "skip", skp },
{ "loopVar", counter },
{ "start", GetCodeForExpression(startCount) }
}));
}
if (command.Type == ASTNodeType.FunctionDefinition)
{
var fn = (ASTFunctionDefinition)command;
var fnName = fn.FunctionName;
var fnType = fnName.IsString ? "string" : "number";
var args = new List <string>();
foreach (var arg in fn.Arguments)
{
var aType = arg.IsString ? "string" : "number";
var vr = GetCodeForVar(arg, false);
var aCode = Target.GetSnippet("functions", aType + "Arg", "arg", vr);
args.Add(aCode);
}
var argString = string.Join(Target.GetSnippet("functions", "argSeperator"), args);
var fnCode = Target.GetComplexSnippet("functions", fnType + "Declaration", new Dictionary <string, string>()
{
{ "name", GetCodeForVar(fnName, false) },
{ "args", argString },
{ "exp", GetCodeForExpression(fn.Expression) }
});
declarations += fnCode;
return("");
}
// TODO: A more generic if (isExpression(command))
if (command.Type == ASTNodeType.Call)
{
var code = GetCodeForCall((ASTCall)command);
return(Target.GetSnippet("commands", "expression", "exp", code));
}
return(Croak("Unsupported AST Node in new transpiler."));
}