private AstItem ReadForLoop(TokenIterator tokens)
{
//for i in 0..5 [inc 1] {...}
tokens.PopExpected(TokenKind.For);
var varName = tokens.PopExpected(TokenKind.Word);
tokens.PopExpected(TokenKind.In);
var startExpression = ReadExpression(tokens, TokenKind.To);
tokens.PopExpected(TokenKind.To);
var endExpression = ReadExpression(tokens, new List <TokenKind>()
{
TokenKind.CurlyBracketOpen, TokenKind.Inc
});
var next = tokens.Pop();
AstItem incExpression = AstItem.Immediate("1");
if (next.Kind == TokenKind.Inc)
{
incExpression = ReadExpression(tokens, TokenKind.CurlyBracketOpen);
tokens.PopExpected(TokenKind.CurlyBracketOpen);
}
else
{
Assert.True(next.Kind == TokenKind.CurlyBracketOpen, "Expected 'inc' or '{', got: " + next);
}
var statements = ReadStatements(tokens);
tokens.PopExpected(TokenKind.CurlyBracketClose);
return(AstItem.ForLoop(varName.Value, startExpression, endExpression, incExpression, statements));
}
