public static IExpression ParseExpression(ConsideredTokens consideredTokens, Action tweakTokens, out ParseError error)
{
error = null;
switch (consideredTokens.Current.Type)
{
case TokenType.INT:
{
if (consideredTokens.Next.Type == TokenType.SEMICOLON)
{
var expression = new IntegerLiteralExpression(consideredTokens.Current);
tweakTokens();
tweakTokens();
return(expression);
}
if (consideredTokens.Next.Type == TokenType.PLUS)
{
return(ParseOperatorExpression(consideredTokens, tweakTokens, out error));
}
}
break;
default: throw new NotImplementedException();
}
throw new NotImplementedException();
}
public IStatement Parse(ConsideredTokens consideredTokens, Action tweakTokens, out ParseError error)
{
var letToken = consideredTokens.Current;
tweakTokens();
if (consideredTokens.Current.Type != TokenType.IDENT)
{
error = new ParseError(StatementType.Let, TokenType.IDENT, consideredTokens.Current.Type);
tweakTokens();
return(null);
}
var identifer = new Identifier(consideredTokens.Current);
tweakTokens();
if (consideredTokens.Current.Type != TokenType.ASSIGN)
{
error = new ParseError(StatementType.Let, TokenType.ASSIGN, consideredTokens.Current.Type);
tweakTokens();
return(null);
}
tweakTokens();
var value = ExpressionParser.ParseExpression(consideredTokens, tweakTokens, out var errorExpression);
error = value == null
? errorExpression
: ParseError.None;
return(new LetStatement(letToken, identifer, value));
}
public IStatement Parse(ConsideredTokens consideredTokens, Action tweakTokens, out ParseError error)
{
var returnToken = consideredTokens.Current;
tweakTokens();
var value = ExpressionParser.ParseExpression(consideredTokens, tweakTokens, out var errorExpression);
error = value == null
? errorExpression
: ParseError.None;
return(new ReturnStatement(returnToken, value));
}
private static IExpression ParseOperatorExpression(ConsideredTokens consideredTokens, Action tweakTokens, out ParseError error)
{
throw new NotImplementedException();
}
public IStatement Parse(ConsideredTokens consideredTokens, Action tweakTokens, out ParseError error)
{
throw new NotImplementedException();
}
