//
// letStatement: 'let' varName ('[' expression ']')? '=' expression ';'
public void CompileLetStatement(int depth)
{
bool isLeftArray = false;
// compile: 'let'
var letToken = Eat("let");
// compile: varName
var varNameToken = EatIdentifier();
var sbVarName = SymbolTableManager.Find(varNameToken.Value);
// compile: ('[' expression ']')?
if (_tokenizer.CurrentToken.Value == "[")
{
isLeftArray = true;
// compile: '['
var leftBracketToken = Eat("[");
// compile: expression
CompileExpression(depth + 1, AssignmentType.LEFT);
// write array
_vmWriter.WritePush(sbVarName.KindDisplay, sbVarName.Number);
_vmWriter.WriteOp(new Token {
Value = "+"
});
// compile: ']'
var rightBracketToken = Eat("]");
}
// compile: '='
var assignmentToken = Eat("=");
// compile: expression
CompileExpression(depth + 1, AssignmentType.RIGHT);
// pop varAssigned
if (isLeftArray)
{
_vmWriter.WritePop("temp", 0);
_vmWriter.WritePop("pointer", 1);
_vmWriter.WritePush("temp", 0);
_vmWriter.WritePop("that", 0);
}
else
{
_vmWriter.WritePop(sbVarName.KindDisplay, sbVarName.Number);
}
// compile: ';'
var semiColonToken = Eat(";");
}
public void WriteExpr(CompilationUnit compUnit)
{
var compUnits = compUnit.CompUnits;
if (compUnits.Count == 1)
{
Token token = compUnits[0];
if (token.TokenType == TokenType.INT_CONST)
{
_vmWriter.WritePush("constant", Convert.ToInt32(token.Value));
}
else if (token.TokenType == TokenType.IDENTIFIER)
{
var sbUnit = SymbolTableManager.Find(token.Value);
_vmWriter.WritePush(sbUnit.Kind.ToString(), sbUnit.Number);
}
}
}
//
// subroutineCall: subroutineName '(' expressionList ')' | (className | varName) '.' subroutineName '(' expressionList '}'
public void CompileSubroutineCall(int depth)
{
int args = 0;
int argadder = 0;
string sbSubName = string.Empty;
var nextToken = _tokenizer.Peek();
// compile: subroutineName '(' expressionList ')'
if (nextToken.Value == "(")
{
argadder = 1;
// compile: subroutineName
var subName = EatIdentifier();
sbSubName = className + "." + subName.Value;
// handle: push 'this' to stack -> push pointer 0
_vmWriter.WritePush("pointer", 0);
// compile: '('
var leftParenToken = Eat("(");
// compile: expressionList
args = CompileExpressionList(depth) + argadder;
// compile: ')'
var rightParenToken = Eat(")");
}
else if (nextToken.Value == ".")
{
// compile: (className | varName)
var nameToken = EatIdentifier();
var sbClass = SymbolTableManager.Find(nameToken.Value);
if (sbClass == null)
{ // handle: class.function(...)
sbSubName = nameToken.Value;
}
else
{ // handle: obj.method(...)
argadder = 1;
sbSubName = sbClass.Type;
var sbObj = SymbolTableManager.Find(nameToken.Value);
_vmWriter.WritePush(sbObj.KindDisplay, sbObj.Number);
}
// compile '.'
var dotToken = Eat(".");
sbSubName += dotToken.Value;
// compile: subroutineName
var subNameToken = EatIdentifier();
sbSubName += subNameToken.Value;
// compile: '('
var leftParenToken = Eat("(");
// compile: expression
args = CompileExpressionList(depth) + argadder;
// compile: ')'
var rightParenToken = Eat(")");
}
// write call
_vmWriter.WriteCall(sbSubName, args);
}
//
// term : integerConstant | stringConstant | keywordConstant | unaryOp term | '(' expression ')' | varName | varName '[' expression ']' | subroutineCall
public void CompileTerm(int depth, AssignmentType assignType)
{
// compile: integerConstant
if (_tokenizer.CurrentToken.TokenType == TokenType.INT_CONST)
{
_vmWriter.WritePush("constant", Convert.ToInt32(_tokenizer.CurrentToken.Value));
_tokenizer.Advance();
}
// compile: stringConstant
else if (_tokenizer.CurrentToken.TokenType == TokenType.STRING_CONST)
{
int strLen = _tokenizer.CurrentToken.Value.Length;
_vmWriter.WritePush("constant", strLen);
_vmWriter.WriteCall("String.new", 1);
foreach (char strChar in _tokenizer.CurrentToken.Value)
{
_vmWriter.WritePush("constant", (int)strChar);
_vmWriter.WriteCall("String.appendChar", 2);
}
_tokenizer.Advance();
}
// compile: keywordConstant
else if (_tokenizer.CurrentToken.GetKeywordType() == Types.KeywordType.TRUE ||
_tokenizer.CurrentToken.GetKeywordType() == Types.KeywordType.FALSE ||
_tokenizer.CurrentToken.GetKeywordType() == Types.KeywordType.NULL ||
_tokenizer.CurrentToken.GetKeywordType() == Types.KeywordType.THIS)
{
if (_tokenizer.CurrentToken.GetKeywordType() == KeywordType.TRUE)
{
_vmWriter.WritePush("constant", 0);
_vmWriter.WriteUnaryOp(new Token {
Value = "~"
});
}
if (_tokenizer.CurrentToken.GetKeywordType() == KeywordType.FALSE)
{
_vmWriter.WritePush("constant", 0);
}
if (_tokenizer.CurrentToken.GetKeywordType() == KeywordType.THIS)
{
_vmWriter.WritePush("pointer", 0);
}
if (_tokenizer.CurrentToken.GetKeywordType() == KeywordType.NULL)
{
_vmWriter.WritePush("constant", 0);
}
_tokenizer.Advance();
}
// compile: unaryOp term
else if (_tokenizer.CurrentToken.Value == "~" || _tokenizer.CurrentToken.Value == "-")
{
// compile: unaryOp
var unaryOpToken = _tokenizer.CurrentToken;
_tokenizer.Advance();
// compile: term
CompileTerm(depth + 1, assignType);
// write op
_vmWriter.WriteUnaryOp(unaryOpToken);
}
// compile: '(' expression ')'
else if (_tokenizer.CurrentToken.Value == "(")
{
// compile '('
var leftParenToken = Eat("(");
// compile: expression
CompileExpression(depth + 1, assignType);
// compile: ')'
var rightParenToken = Eat(")");
}
// compile: varName | varName '[' expression ']' | subroutineCall '(' expression ')'
else if (_tokenizer.CurrentToken.TokenType == TokenType.IDENTIFIER)
{
var nextToken = _tokenizer.Peek();
var sbVarName = SymbolTableManager.Find(_tokenizer.CurrentToken.Value);
// compile: varName '[' expression ']'
if (nextToken.Value == "[")
{
// compile: varName
var varNameToken = EatIdentifier();
// compile: '['
var leftBracketToken = Eat("[");
// compile: expression
CompileExpression(depth + 1, assignType);
_vmWriter.WritePush(sbVarName.KindDisplay, sbVarName.Number);
_vmWriter.WriteOp(new Token {
Value = "+"
});
// add offset
_vmWriter.WritePop("pointer", 1);
_vmWriter.WritePush("that", 0);
// compile: ']'
var rightBracketToken = Eat("]");
}
// compile: subroutineCall
else if (nextToken.Value == "(" || nextToken.Value == ".")
{
CompileSubroutineCall(depth + 1);
}
// compile: varName
else
{
var varNameToken = EatIdentifier();
_vmWriter.WritePush(sbVarName.KindDisplay, sbVarName.Number);
}
}
}