I posted it to http://discuss.rust-lang.org/. Thanks!
On Wed, Jan 27, 2016 at 5:41 PM, Kenneth Adam Miller <
kennethadammil...@gmail.com> wrote:
> Hey,
>
> Without answering your question, I think you might be better off posting
> your question at reddit.com/r/rust because this mailing list has very low
> participation.
>
> On Wed, Jan 27, 2016 at 11:18 AM, Johan Tibell <johan.tib...@gmail.com>
> wrote:
>
>> Hi!
>>
>> I'm trying to read the compiler code (mostly because I'm curious) and
>> right now I'm trying to understand the handling of negative integer/float
>> literals.
>>
>> In token.rs we have:
>>
>> pub enum Lit {
>> ...
>> Integer(ast::Name),
>> Float(ast::Name),
>> ...
>> }
>>
>> So at this stage these literals are still just (interned) strings. In
>> lexer/mod.rs we can see that the lexer doesn't consume any plus/minus
>> sign, so the above tokens don't contain them.
>>
>> In ast.rs we have:
>>
>> pub enum Expr_ {
>> ...
>> /// A literal (For example: `1u8`, `"foo"`)
>> ExprLit(P<Lit>),
>> ...
>> }
>>
>> pub enum Lit_ {
>> ...
>> /// An integer literal (`1u8`)
>> LitInt(u64, LitIntType),
>> /// A float literal (`1f64` or `1E10f64`)
>> LitFloat(InternedString, FloatTy),
>> /// A float literal without a suffix (`1.0 or 1.0E10`)
>> LitFloatUnsuffixed(InternedString),
>> ...
>> }
>>
>> pub enum Sign {
>> Minus,
>> Plus
>> }
>>
>> pub enum LitIntType {
>> SignedIntLit(IntTy, Sign),
>> UnsignedIntLit(UintTy),
>> UnsuffixedIntLit(Sign)
>> }
>>
>> I'd expect that somewhere in the code we'd construct e.g. an SignedIntLit
>> with a Minus in it, but I cannot find a single place that does this after
>> looking for all uses of ast::Minus ast::SignedIntLit, etc.
>>
>> So my question is, *since the sign isn't lexed together with the
>> literal, how is it eventually added to the literal that's stored in in e.g.
>> ast::LitInt?*
>>
>> -- Johan
>>
>>
>> _______________________________________________
>> Rust-dev mailing list
>> Rust-dev@mozilla.org
>> https://mail.mozilla.org/listinfo/rust-dev
>>
>>
>
_______________________________________________
Rust-dev mailing list
Rust-dev@mozilla.org
https://mail.mozilla.org/listinfo/rust-dev
