/// <summary>
/// 1. var name;
/// 2. var age = 21;
/// 3. canDrink = age >= 21;
/// 4. canVote = CanVote(age);
/// </summary>
/// <returns></returns>
public Expr ParseAssignment(bool expectVar, bool expectId, Expr varExp)
{
var initiatorToken = _tokenIt.NextToken;
var declarations = new List <AssignExpr>();
if (expectVar)
{
_tokenIt.Expect(Tokens.Var);
}
if (expectId)
{
varExp = ParseVariable();
}
var assignToken = _tokenIt.NextToken;
// Case 1: var name;
if (_tokenIt.IsEndOfStmtOrBlock())
{
AddAssignment(expectVar, varExp, null, declarations, _tokenIt.NextToken);
return(Exprs.AssignMulti(expectVar, declarations, initiatorToken));
}
// Case 2: var name = <expression>
Expr valueExp = null;
assignToken = _tokenIt.NextToken;
if (_tokenIt.NextToken.Token == Tokens.Assignment)
{
_tokenIt.Advance();
valueExp = _parser.ParseExpression(Terminators.ExpVarDeclarationEnd, passNewLine: false);
}
AddAssignment(expectVar, varExp, valueExp, declarations, assignToken);
if (_tokenIt.IsEndOfStmtOrBlock() || _tokenIt.NextToken.Token.Kind == TokenKind.Keyword)
{
return(Exprs.AssignMulti(expectVar, declarations, initiatorToken));
}
// Case 3: Multiple var a,b,c; or var a = 1, b = 2, c = 3;
_tokenIt.Expect(Tokens.Comma);
while (true)
{
varExp = ParseVariable();
valueExp = null;
assignToken = _tokenIt.NextToken;
// , or expression?
if (_tokenIt.NextToken.Token == Tokens.Assignment)
{
_tokenIt.Advance();
valueExp = _parser.ParseExpression(Terminators.ExpVarDeclarationEnd, passNewLine: false);
}
AddAssignment(expectVar, varExp, valueExp, declarations, assignToken);
if (_tokenIt.IsEndOfStmtOrBlock())
{
break;
}
_tokenIt.Expect(Tokens.Comma);
}
return(Exprs.AssignMulti(expectVar, declarations, initiatorToken));
}
