David Tolnay | 395392d | 2019-03-11 11:21:44 -0700 | [diff] [blame] | 1 | use syn::{Arm, Ident, Result, Variant}; |
David Tolnay | c621f44 | 2019-05-11 12:15:31 -0700 | [diff] [blame] | 2 | use syn::{Error, Field, Pat, PatIdent}; |
David Tolnay | 395392d | 2019-03-11 11:21:44 -0700 | [diff] [blame] | 3 | |
| 4 | use crate::compare::Path; |
| 5 | use crate::format; |
| 6 | use crate::parse::Input::{self, *}; |
| 7 | |
| 8 | pub fn sorted(input: Input) -> Result<()> { |
| 9 | let paths = match input { |
| 10 | Enum(item) => collect_paths(item.variants)?, |
David Tolnay | c621f44 | 2019-05-11 12:15:31 -0700 | [diff] [blame] | 11 | Struct(fields) => collect_paths(fields.named)?, |
David Tolnay | 395392d | 2019-03-11 11:21:44 -0700 | [diff] [blame] | 12 | Match(expr) | Let(expr) => collect_paths(expr.arms)?, |
| 13 | }; |
| 14 | |
| 15 | for i in 1..paths.len() { |
| 16 | let cur = &paths[i]; |
| 17 | if *cur < paths[i - 1] { |
| 18 | let lesser = cur; |
| 19 | let correct_pos = paths[..i - 1].binary_search(cur).unwrap_err(); |
| 20 | let greater = &paths[correct_pos]; |
| 21 | return Err(format::error(lesser, greater)); |
| 22 | } |
| 23 | } |
| 24 | |
| 25 | Ok(()) |
| 26 | } |
| 27 | |
| 28 | fn collect_paths<I>(iter: I) -> Result<Vec<Path>> |
| 29 | where |
| 30 | I: IntoIterator, |
| 31 | I::Item: IntoPath, |
| 32 | { |
| 33 | iter.into_iter().map(IntoPath::into_path).collect() |
| 34 | } |
| 35 | |
| 36 | trait IntoPath { |
| 37 | fn into_path(self) -> Result<Path>; |
| 38 | } |
| 39 | |
| 40 | impl IntoPath for Variant { |
| 41 | fn into_path(self) -> Result<Path> { |
| 42 | Ok(Path { |
| 43 | segments: vec![self.ident], |
| 44 | }) |
| 45 | } |
| 46 | } |
| 47 | |
Jeremy Banks | c41add7 | 2019-05-11 10:52:18 -0400 | [diff] [blame] | 48 | impl IntoPath for Field { |
| 49 | fn into_path(self) -> Result<Path> { |
| 50 | Ok(Path { |
| 51 | segments: vec![self.ident.expect("must be named field")], |
| 52 | }) |
| 53 | } |
| 54 | } |
| 55 | |
David Tolnay | 395392d | 2019-03-11 11:21:44 -0700 | [diff] [blame] | 56 | impl IntoPath for Arm { |
| 57 | fn into_path(self) -> Result<Path> { |
| 58 | // Sort by just the first pat. |
| 59 | let pat = self.pats.into_iter().next().expect("at least one pat"); |
| 60 | |
| 61 | let segments = match pat { |
| 62 | Pat::Wild(pat) => vec![Ident::from(pat.underscore_token)], |
David Tolnay | 3d87040 | 2019-03-11 11:37:25 -0700 | [diff] [blame] | 63 | Pat::Path(pat) => idents_of_path(pat.path), |
| 64 | Pat::Struct(pat) => idents_of_path(pat.path), |
| 65 | Pat::TupleStruct(pat) => idents_of_path(pat.path), |
David Tolnay | 395392d | 2019-03-11 11:21:44 -0700 | [diff] [blame] | 66 | Pat::Ident(ref pat) if is_just_ident(pat) => vec![pat.ident.clone()], |
| 67 | other => { |
| 68 | let msg = "unsupported by #[remain::sorted]"; |
| 69 | return Err(Error::new_spanned(other, msg)); |
| 70 | } |
| 71 | }; |
| 72 | |
| 73 | Ok(Path { segments }) |
| 74 | } |
| 75 | } |
| 76 | |
David Tolnay | 3d87040 | 2019-03-11 11:37:25 -0700 | [diff] [blame] | 77 | fn idents_of_path(path: syn::Path) -> Vec<Ident> { |
| 78 | path.segments.into_iter().map(|seg| seg.ident).collect() |
| 79 | } |
| 80 | |
David Tolnay | 395392d | 2019-03-11 11:21:44 -0700 | [diff] [blame] | 81 | fn is_just_ident(pat: &PatIdent) -> bool { |
| 82 | pat.by_ref.is_none() && pat.mutability.is_none() && pat.subpat.is_none() |
| 83 | } |