925f7fad57
`tokenstream::Spacing` appears on all `TokenTree::Token` instances, both punct and non-punct. Its current usage: - `Joint` means "can join with the next token *and* that token is a punct". - `Alone` means "cannot join with the next token *or* can join with the next token but that token is not a punct". The fact that `Alone` is used for two different cases is awkward. This commit augments `tokenstream::Spacing` with a new variant `JointHidden`, resulting in: - `Joint` means "can join with the next token *and* that token is a punct". - `JointHidden` means "can join with the next token *and* that token is a not a punct". - `Alone` means "cannot join with the next token". This *drastically* improves the output of `print_tts`. For example, this: ``` stringify!(let a: Vec<u32> = vec![];) ``` currently produces this string: ``` let a : Vec < u32 > = vec! [] ; ``` With this PR, it now produces this string: ``` let a: Vec<u32> = vec![] ; ``` (The space after the `]` is because `TokenTree::Delimited` currently doesn't have spacing information. The subsequent commit fixes this.) The new `print_tts` doesn't replicate original code perfectly. E.g. multiple space characters will be condensed into a single space character. But it's much improved. `print_tts` still produces the old, uglier output for code produced by proc macros. Because we have to translate the generated code from `proc_macro::Spacing` to the more expressive `token::Spacing`, which results in too much `proc_macro::Along` usage and no `proc_macro::JointHidden` usage. So `space_between` still exists and is used by `print_tts` in conjunction with the `Spacing` field. This change will also help with the removal of `Token::Interpolated`. Currently interpolated tokens are pretty-printed nicely via AST pretty printing. `Token::Interpolated` removal will mean they get printed with `print_tts`. Without this change, that would result in much uglier output for code produced by decl macro expansions. With this change, AST pretty printing and `print_tts` produce similar results. The commit also tweaks the comments on `proc_macro::Spacing`. In particular, it refers to "compound tokens" rather than "multi-char operators" because lifetimes aren't operators.
48 lines
1.4 KiB
Plaintext
48 lines
1.4 KiB
Plaintext
PRINT-ATTR INPUT (DISPLAY): #[rustc_dummy] { 1 +1; }
|
|
PRINT-ATTR DEEP-RE-COLLECTED (DISPLAY): #[rustc_dummy] { 1 + 1 ; }
|
|
PRINT-ATTR INPUT (DEBUG): TokenStream [
|
|
Punct {
|
|
ch: '#',
|
|
spacing: Alone,
|
|
span: $DIR/keep-expr-tokens.rs:22:5: 22:6 (#0),
|
|
},
|
|
Group {
|
|
delimiter: Bracket,
|
|
stream: TokenStream [
|
|
Ident {
|
|
ident: "rustc_dummy",
|
|
span: $DIR/keep-expr-tokens.rs:22:7: 22:18 (#0),
|
|
},
|
|
],
|
|
span: $DIR/keep-expr-tokens.rs:22:6: 22:19 (#0),
|
|
},
|
|
Group {
|
|
delimiter: Brace,
|
|
stream: TokenStream [
|
|
Literal {
|
|
kind: Integer,
|
|
symbol: "1",
|
|
suffix: None,
|
|
span: $DIR/keep-expr-tokens.rs:23:7: 23:8 (#0),
|
|
},
|
|
Punct {
|
|
ch: '+',
|
|
spacing: Alone,
|
|
span: $DIR/keep-expr-tokens.rs:23:9: 23:10 (#0),
|
|
},
|
|
Literal {
|
|
kind: Integer,
|
|
symbol: "1",
|
|
suffix: None,
|
|
span: $DIR/keep-expr-tokens.rs:23:10: 23:11 (#0),
|
|
},
|
|
Punct {
|
|
ch: ';',
|
|
spacing: Alone,
|
|
span: $DIR/keep-expr-tokens.rs:23:11: 23:12 (#0),
|
|
},
|
|
],
|
|
span: $DIR/keep-expr-tokens.rs:23:5: 23:14 (#0),
|
|
},
|
|
]
|