/// <summary>
/// Declares a method (a function in a class).
/// Possible todo: merge this with FunctionDeclaration, as they share a lot of code.
/// </summary>
private void MethodDeclaration(string fnType, ELoxFunctionType fnType2)
{
Tokens.Consume(IDENTIFIER, $"Expect {fnType} name.");
if (Tokens.Previous().Lexeme == "init")
{
fnType2 = ELoxFunctionType.TYPE_INITIALIZER;
}
string fnName = Tokens.Previous().Lexeme;
int fnLine = LineOfLastToken;
LoxCompiler fnCompiler = new LoxCompiler(Tokens, fnType2, fnName, this, _CurrentClass);
fnCompiler.FunctionBody();
fnCompiler.EndCompiler();
EmitOpcode(fnLine, OP_LOAD_FUNCTION);
EmitData(fnLine, (byte)fnCompiler.Arity);
// EmitConstantIndex(MakeBitStrConstant(fnName), _FixupConstants); // has fixup
AddFixup(fnLine, fnCompiler);
EmitData(fnLine, (byte)fnCompiler._UpvalueCount);
for (int i = 0; i < fnCompiler._UpvalueCount; i++)
{
EmitData(fnLine, (byte)(fnCompiler._UpvalueData[i].IsLocal ? 1 : 0));
EmitData(fnLine, (byte)(fnCompiler._UpvalueData[i].Index));
}
EmitOpcode(fnLine, OP_METHOD);
EmitConstantIndex(fnLine, MakeBitStrConstant(fnName), _FixupConstants); // has fixup
}
private LoxCompiler(TokenList tokens, ELoxFunctionType type, string name, LoxCompiler enclosing, LoxCompilerClass enclosingClass)
: base(tokens, name)
{
_FunctionType = type;
Arity = 0;
_Chunk = new GearsChunk(name);
_Rules = new List <Rule>();
_EnclosingCompiler = enclosing;
_CurrentClass = enclosingClass;
// stack slot zero is used for 'this' reference in methods, and is empty for script/functions:
if (type != ELoxFunctionType.TYPE_FUNCTION)
{
_LocalVarData[_LocalCount++] = new LoxCompilerLocal("this", 0);
}
else
{
_LocalVarData[_LocalCount++] = new LoxCompilerLocal(string.Empty, 0);
}
}
/// <summary>
/// Attempts to compile the passed source, tokenizing first.
/// If compilation is successful, compiler.Chunk will be set.
/// If compilation fails, status will be the error message.
/// </summary>
public static bool TryCompileFromSource(string path, string source, out GearsChunk chunk, out string status)
{
try {
TokenList tokens = new LoxTokenizer(path, source).ScanTokens();
LoxCompiler compiler = new LoxCompiler(tokens, ELoxFunctionType.TYPE_SCRIPT, path, null, null);
if (compiler.Compile())
{
chunk = compiler._Chunk;
status = null;
return(true);
}
status = $"LoxCompiler: uncaught error while compiling {path}.";
chunk = null;
return(false);
}
catch (CompilerException e) {
chunk = null;
status = $"LoxCompiler at {e.TargetSite.DeclaringType.Name}.{e.TargetSite.Name} {path} {e}";
return(false);
}
}
/// <summary>
/// function → IDENTIFIER "(" parameters? ")" block ;
/// parameters → IDENTIFIER( "," IDENTIFIER )* ;
/// </summary>
private void FunctionDeclaration(string fnType, ELoxFunctionType fnType2)
{
int global = ParseVariable($"Expect {fnType} name.");
MarkInitialized();
string fnName = Tokens.Previous().Lexeme;
int fnLine = LineOfLastToken;
LoxCompiler fnCompiler = new LoxCompiler(Tokens, fnType2, fnName, this, _CurrentClass);
fnCompiler.FunctionBody();
fnCompiler.EndCompiler();
EmitOpcode(fnLine, OP_LOAD_FUNCTION);
EmitData(fnLine, (byte)fnCompiler.Arity);
// EmitConstantIndex(MakeBitStrConstant(fnName), _FixupConstants); // has fixup
AddFixup(fnLine, fnCompiler);
// EmitOpcode(OP_CLOSURE);
EmitData(fnLine, (byte)fnCompiler._UpvalueCount);
for (int i = 0; i < fnCompiler._UpvalueCount; i++)
{
EmitData(fnLine, (byte)(fnCompiler._UpvalueData[i].IsLocal ? 1 : 0));
EmitData(fnLine, (byte)(fnCompiler._UpvalueData[i].Index));
}
DefineVariable(fnLine, global);
}
private void AddFixup(int line, LoxCompiler fn)
{
_FixupFns.Add(fn);
fn._OriginAddress = _Chunk.SizeCode;
EmitData(line, 0, 0); // fn jump - to fix up
}