private void CompileSubroutineBody(string subroutineName, JackTokenizer.JackKeywordTypes subroutineKind)
{
xml += "<subroutineBody>\n";
// '{' varDec* statements '}'
Nx().ExpectSymbol('{');
this.CompileVarDecs(subroutineName, subroutineKind);
switch (subroutineKind)
{
case JackTokenizer.JackKeywordTypes.CONSTRUCTOR:
this.vm.WritePush(VMWriter.Segment.CONST, this.symbolTable.VarCount(SymbolTable.Kind.FIELD));
this.vm.WriteCall("Memory.alloc", 1);
this.vm.WritePop(VMWriter.Segment.POINTER, 0);
break;
case JackTokenizer.JackKeywordTypes.METHOD:
this.vm.WritePush(VMWriter.Segment.ARG, 0);
this.vm.WritePop(VMWriter.Segment.POINTER, 0);
break;
}
this.CompileStatements(subroutineName);
Nx().ExpectSymbol('}');
xml += "</subroutineBody>\n";
}
private void CompileVarDecs(string subroutineName, JackTokenizer.JackKeywordTypes subroutineKind)
{
while (Nx(increment: false).ExpectKeyword(JackTokenizer.JackKeywordTypes.VAR, throwException: false))
{
this.CompileVarDec(subroutineName);
}
if (subroutineKind == JackTokenizer.JackKeywordTypes.CONSTRUCTOR)
{
}
this.vm.WriteFunction($"{this.className}.{subroutineName}", this.symbolTable.VarCount(SymbolTable.Kind.VAR));
}
private void CompileClassVarDecs()
{
var expectedKeywords = new JackTokenizer.JackKeywordTypes[] {
JackTokenizer.JackKeywordTypes.STATIC,
JackTokenizer.JackKeywordTypes.FIELD
};
while (Nx(increment: false).ExpectKeyword(expectedKeywords, throwException: false))
{
this.CompileClassVarDec();
}
}
private void CompileSubroutineDecs()
{
var expectedKeywords = new JackTokenizer.JackKeywordTypes[] {
JackTokenizer.JackKeywordTypes.CONSTRUCTOR,
JackTokenizer.JackKeywordTypes.FUNCTION,
JackTokenizer.JackKeywordTypes.METHOD
};
while (Nx(false).ExpectKeyword(expectedKeywords, throwException: false))
{
this.CompileSubroutineDec();
}
}
private void CompileStatements(string subroutineName)
{
xml += "<statements>\n";
var expectedKeywords = new JackTokenizer.JackKeywordTypes[] {
JackTokenizer.JackKeywordTypes.LET,
JackTokenizer.JackKeywordTypes.IF,
JackTokenizer.JackKeywordTypes.WHILE,
JackTokenizer.JackKeywordTypes.DO,
JackTokenizer.JackKeywordTypes.RETURN
};
while (Nx(increment: false).ExpectKeyword(expectedKeywords, throwException: false))
{
this.CompileStatement(subroutineName);
}
xml += "</statements>\n";
}
public static bool ExpectKeyword(this JackTokenizer.ClassifiedJackToken token, JackTokenizer.JackKeywordTypes keyword, bool throwException = true)
{
if (token.TokenType() == JackTokenizer.JackTokenType.keyword &&
token.ParseKeyWord() == keyword)
{
return(true);
}
else
{
if (throwException)
{
throw new Exception("Expected keyword 'class' but found '" + token.value + "'.");
}
else
{
return(false);
}
}
}
