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Improving macro expansion section (#1875)

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Arthur Milchior 2024-01-29 20:53:39 +01:00 committed by GitHub
parent ea1767da49
commit 11aa615575
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1 changed files with 5 additions and 9 deletions
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src/macro-expansion.md
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@ -292,13 +292,8 @@ macro_rules! foo { () => { println!(); } }
fn main() { foo!(); } fn main() { foo!(); }
``` ```
In this code, the AST nodes that are finally generated would have hierarchy: In this code, the AST nodes that are finally generated would have hierarchy
`root -> id(foo) -> id(println)`.
```
root
expn_id_foo
expn_id_println
```
### The Macro Definition Hierarchy ### The Macro Definition Hierarchy
@ -397,8 +392,9 @@ macro foo($i: ident) { $i }
foo!(bar!(baz)); foo!(bar!(baz));
``` ```
For the `baz` AST node in the final output, the first hierarchy is `ROOT -> For the `baz` AST node in the final output, the expansion-order hierarchy is
id(foo) -> id(bar) -> baz`, while the third hierarchy is `ROOT -> baz`. `ROOT -> id(foo) -> id(bar) -> baz`, while the call-site hierarchy is `ROOT ->
baz`.
### Macro Backtraces ### Macro Backtraces