Merge pull request #206 from dtolnay/pat

Pattern parser to preserve all spans in `if let` and `for`
dtolnay · Nov 28, 2021 · 865de15 · 865de15
2 parents b577cd9 + da5c3fd
commit 865de15
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Showing 2 changed files with 173 additions and 16 deletions.
diff --git a/src/ensure.rs b/src/ensure.rs
@@ -143,8 +143,8 @@ macro_rules! __parse_ensure {
         $crate::__parse_ensure!(0 $stack $bail ($($fuel)*) {($($buf)* $neg) $($parse)*} ($($rest)*) $($rest)*)
     };
 
-    (0 $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($let:tt $($dup:tt)*) let $(|)? $($pat:pat)|+ = $($rest:tt)*) => {
-        $crate::__parse_ensure!(0 $stack $bail ($($fuel)*) {($($buf)* $let $($pat)|+ =) $($parse)*} ($($rest)*) $($rest)*)
+    (0 $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($let:tt $($dup:tt)*) let $($rest:tt)*) => {
+        $crate::__parse_ensure!(pat $stack $bail ($($fuel)*) {($($buf)* $let) $($parse)*} ($($rest)*) $($rest)*)
     };
 
     (0 $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($life:tt $colon:tt $($dup:tt)*) $label:lifetime : $($rest:tt)*) => {
@@ -181,8 +181,8 @@ macro_rules! __parse_ensure {
         $crate::__parse_ensure!(0 (cond $stack) $bail ($($fuel)*) {($($buf)* $while) $($parse)*} ($($rest)*) $($rest)*)
     };
 
-    (0 $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($for:tt $($dup:tt)*) for $(|)? $($pat:pat)|+ in $($rest:tt)*) => {
-        $crate::__parse_ensure!(0 (cond $stack) $bail ($($fuel)*) {($($buf)* $for $($pat)|+ in) $($parse)*} ($($rest)*) $($rest)*)
+    (0 $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($for:tt $($dup:tt)*) for $($rest:tt)*) => {
+        $crate::__parse_ensure!(pat (cond $stack) $bail ($($fuel)*) {($($buf)* $for) $($parse)*} ($($rest)*) $($rest)*)
     };
 
     (atom (cond $stack:tt) $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($brace:tt $($dup:tt)*) {$($block:tt)*} $($rest:tt)*) => {
@@ -238,15 +238,15 @@ macro_rules! __parse_ensure {
     // path expressions
 
     (0 $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($colons:tt $($dup:tt)*) :: $ident:ident $($rest:tt)*) => {
-        $crate::__parse_ensure!(epath $stack $bail ($($fuel)*) {($($buf)* $colons $ident) $($parse)*} ($($rest)*) $($rest)*)
+        $crate::__parse_ensure!(epath (atom $stack) $bail ($($fuel)*) {($($buf)* $colons $ident) $($parse)*} ($($rest)*) $($rest)*)
     };
 
     (0 $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} $dup:tt $ident:ident $($rest:tt)*) => {
-        $crate::__parse_ensure!(epath $stack $bail ($($fuel)*) {($($buf)* $ident) $($parse)*} ($($rest)*) $($rest)*)
+        $crate::__parse_ensure!(epath (atom $stack) $bail ($($fuel)*) {($($buf)* $ident) $($parse)*} ($($rest)*) $($rest)*)
     };
 
     (0 $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($langle:tt $($dup:tt)*) < $($rest:tt)*) => {
-        $crate::__parse_ensure!(type (qpath (epath $stack)) $bail ($($fuel)*) {($($buf)* $langle) $($parse)*} ($($rest)*) $($rest)*)
+        $crate::__parse_ensure!(type (qpath (epath (atom $stack))) $bail ($($fuel)*) {($($buf)* $langle) $($parse)*} ($($rest)*) $($rest)*)
     };
 
     (epath $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($colons:tt $langle:tt $($dup:tt)*) :: < $($rest:tt)*) => {
@@ -261,20 +261,20 @@ macro_rules! __parse_ensure {
         $crate::__parse_ensure!(epath $stack $bail ($($fuel)*) {($($buf)* $colons $ident) $($parse)*} ($($rest)*) $($rest)*)
     };
 
-    (epath $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($bang:tt $args:tt $($dup:tt)*) ! ($($mac:tt)*) $($rest:tt)*) => {
-        $crate::__parse_ensure!(atom $stack $bail ($($fuel)*) {($($buf)* $bang $args) $($parse)*} ($($rest)*) $($rest)*)
+    (epath ($pop:ident $stack:tt) $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($bang:tt $args:tt $($dup:tt)*) ! ($($mac:tt)*) $($rest:tt)*) => {
+        $crate::__parse_ensure!($pop $stack $bail ($($fuel)*) {($($buf)* $bang $args) $($parse)*} ($($rest)*) $($rest)*)
     };
 
-    (epath $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($bang:tt $args:tt $($dup:tt)*) ! [$($mac:tt)*] $($rest:tt)*) => {
-        $crate::__parse_ensure!(atom $stack $bail ($($fuel)*) {($($buf)* $bang $args) $($parse)*} ($($rest)*) $($rest)*)
+    (epath ($pop:ident $stack:tt) $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($bang:tt $args:tt $($dup:tt)*) ! [$($mac:tt)*] $($rest:tt)*) => {
+        $crate::__parse_ensure!($pop $stack $bail ($($fuel)*) {($($buf)* $bang $args) $($parse)*} ($($rest)*) $($rest)*)
     };
 
-    (epath $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($bang:tt $args:tt $($dup:tt)*) ! {$($mac:tt)*} $($rest:tt)*) => {
-        $crate::__parse_ensure!(atom $stack $bail ($($fuel)*) {($($buf)* $bang $args) $($parse)*} ($($rest)*) $($rest)*)
+    (epath ($pop:ident $stack:tt) $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($bang:tt $args:tt $($dup:tt)*) ! {$($mac:tt)*} $($rest:tt)*) => {
+        $crate::__parse_ensure!($pop $stack $bail ($($fuel)*) {($($buf)* $bang $args) $($parse)*} ($($rest)*) $($rest)*)
     };
 
-    (epath $stack:tt $bail:tt (~$($fuel:tt)*) $parse:tt $dup:tt $($rest:tt)*) => {
-        $crate::__parse_ensure!(atom $stack $bail ($($fuel)*) $parse $dup $($rest)*)
+    (epath ($pop:ident $stack:tt) $bail:tt (~$($fuel:tt)*) $parse:tt $dup:tt $($rest:tt)*) => {
+        $crate::__parse_ensure!($pop $stack $bail ($($fuel)*) $parse $dup $($rest)*)
     };
 
     // trailer expressions
@@ -537,6 +537,80 @@ macro_rules! __parse_ensure {
         $crate::__parse_ensure!($pop $stack $bail ($($fuel)*) {($($buf)* >) $($parse)*} (> $($rest)*) > $($rest)*)
     };
 
+    // patterns
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($pipe:tt $($dup:tt)*) | $($rest:tt)*) => {
+        $crate::__parse_ensure!(pat $stack $bail ($($fuel)*) {($($buf)* $pipe) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($eq:tt $($dup:tt)*) = $($rest:tt)*) => {
+        $crate::__parse_ensure!(0 $stack $bail ($($fuel)*) {($($buf)* $eq) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($in:tt $($dup:tt)*) in $($rest:tt)*) => {
+        $crate::__parse_ensure!(0 $stack $bail ($($fuel)*) {($($buf)* $in) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($ref:tt $($dup:tt)*) ref $($rest:tt)*) => {
+        $crate::__parse_ensure!(pat $stack $bail ($($fuel)*) {($($buf)* $ref) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($mut:tt $($dup:tt)*) mut $($rest:tt)*) => {
+        $crate::__parse_ensure!(pat $stack $bail ($($fuel)*) {($($buf)* $mut) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($at:tt $($dup:tt)*) @ $($rest:tt)*) => {
+        $crate::__parse_ensure!(pat $stack $bail ($($fuel)*) {($($buf)* $at) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} $dup:tt $lit:literal $($rest:tt)*) => {
+        $crate::__parse_ensure!(pat $stack $bail ($($fuel)*) {($($buf)* $lit) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($range:tt $($dup:tt)*) .. $($rest:tt)*) => {
+        $crate::__parse_ensure!(pat $stack $bail ($($fuel)*) {($($buf)* $range) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($range:tt $($dup:tt)*) ..= $($rest:tt)*) => {
+        $crate::__parse_ensure!(pat $stack $bail ($($fuel)*) {($($buf)* $range) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($and:tt $($dup:tt)*) & $($rest:tt)*) => {
+        $crate::__parse_ensure!(pat $stack $bail ($($fuel)*) {($($buf)* $and) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($andand:tt $($dup:tt)*) && $($rest:tt)*) => {
+        $crate::__parse_ensure!(pat $stack $bail ($($fuel)*) {($($buf)* $andand) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($paren:tt $($dup:tt)*) ($($content:tt)*) $($rest:tt)*) => {
+        $crate::__parse_ensure!(pat $stack $bail ($($fuel)*) {($($buf)* $paren) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($bracket:tt $($dup:tt)*) [$($content:tt)*] $($rest:tt)*) => {
+        $crate::__parse_ensure!(pat $stack $bail ($($fuel)*) {($($buf)* $bracket) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($brace:tt $($dup:tt)*) {$($content:tt)*} $($rest:tt)*) => {
+        $crate::__parse_ensure!(pat $stack $bail ($($fuel)*) {($($buf)* $brace) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($wild:tt $($dup:tt)*) _ $($rest:tt)*) => {
+        $crate::__parse_ensure!(pat $stack $bail ($($fuel)*) {($($buf)* $wild) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($colons:tt $($dup:tt)*) :: $ident:ident $($rest:tt)*) => {
+        $crate::__parse_ensure!(epath (pat $stack) $bail ($($fuel)*) {($($buf)* $colons $ident) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} $dup:tt $ident:ident $($rest:tt)*) => {
+        $crate::__parse_ensure!(epath (pat $stack) $bail ($($fuel)*) {($($buf)* $ident) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
+    (pat $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($langle:tt $($dup:tt)*) < $($rest:tt)*) => {
+        $crate::__parse_ensure!(type (qpath (epath (pat $stack))) $bail ($($fuel)*) {($($buf)* $langle) $($parse)*} ($($rest)*) $($rest)*)
+    };
+
     // high precedence binary operators
 
     (atom $stack:tt $bail:tt (~$($fuel:tt)*) {($($buf:tt)*) $($parse:tt)*} ($add:tt $($dup:tt)*) + $($rest:tt)*) => {

diff --git a/tests/test_ensure.rs b/tests/test_ensure.rs
@@ -18,7 +18,7 @@
 use anyhow::{anyhow, ensure, Chain, Error, Result};
 use std::fmt::Debug;
 use std::iter;
-use std::marker::PhantomData;
+use std::marker::{PhantomData, PhantomData as P};
 use std::ops::Add;
 use std::ptr;
 
@@ -33,6 +33,7 @@ impl<T> Add<T> for S {
 }
 
 trait Trait: Sized {
+    const V: usize = 0;
     fn t(self, i: i32) -> i32 {
         i
     }
@@ -601,3 +602,85 @@ fn test_as() {
     let test = || Ok(ensure!(0 as int! {...} != 0));
     assert_err(test, "Condition failed: `0 as int! { ... } != 0` (0 vs 0)");
 }
+
+#[test]
+fn test_pat() {
+    let test = || Ok(ensure!(if let ref mut _x @ 0 = 0 { 0 } else { 1 } == 1));
+    assert_err(
+        test,
+        "Condition failed: `if let ref mut _x @ 0 = 0 { 0 } else { 1 } == 1` (0 vs 1)",
+    );
+
+    let test = || Ok(ensure!(if let -1..=1 = 0 { 0 } else { 1 } == 1));
+    assert_err(
+        test,
+        "Condition failed: `if let -1 ..=1 = 0 { 0 } else { 1 } == 1` (0 vs 1)",
+    );
+
+    let test = || Ok(ensure!(if let &0 = &0 { 0 } else { 1 } == 1));
+    assert_err(
+        test,
+        "Condition failed: `if let &0 = &0 { 0 } else { 1 } == 1` (0 vs 1)",
+    );
+
+    let test = || Ok(ensure!(if let &&0 = &&0 { 0 } else { 1 } == 1));
+    assert_err(
+        test,
+        "Condition failed: `if let &&0 = &&0 { 0 } else { 1 } == 1` (0 vs 1)",
+    );
+
+    let test = || Ok(ensure!(if let &mut 0 = &mut 0 { 0 } else { 1 } == 1));
+    assert_err(
+        test,
+        "Condition failed: `if let &mut 0 = &mut 0 { 0 } else { 1 } == 1` (0 vs 1)",
+    );
+
+    let test = || Ok(ensure!(if let &&mut 0 = &&mut 0 { 0 } else { 1 } == 1));
+    assert_err(
+        test,
+        "Condition failed: `if let &&mut 0 = &&mut 0 { 0 } else { 1 } == 1` (0 vs 1)",
+    );
+
+    let test = || Ok(ensure!(if let (0, 1) = (0, 1) { 0 } else { 1 } == 1));
+    assert_err(
+        test,
+        "Condition failed: `if let (0, 1) = (0, 1) { 0 } else { 1 } == 1` (0 vs 1)",
+    );
+
+    let test = || Ok(ensure!(if let [0] = b"\0" { 0 } else { 1 } == 1));
+    assert_err(
+        test,
+        "Condition failed: `if let [0] = b\"\\0\" { 0 } else { 1 } == 1` (0 vs 1)",
+    );
+
+    let p = PhantomData::<u8>;
+    let test = || Ok(ensure!(if let P::<u8> {} = p { 0 } else { 1 } == 1));
+    assert_err(
+        test,
+        "Condition failed: `if let P::<u8> {  } = p { 0 } else { 1 } == 1` (0 vs 1)",
+    );
+
+    let test = || Ok(ensure!(if let ::std::marker::PhantomData = p {} != ()));
+    assert_err(
+        test,
+        "Condition failed: `if let ::std::marker::PhantomData = p { } != ()` (() vs ())",
+    );
+
+    let test = || Ok(ensure!(if let <S as Trait>::V = 0 { 0 } else { 1 } == 1));
+    assert_err(
+        test,
+        "Condition failed: `if let <S as Trait>::V = 0 { 0 } else { 1 } == 1` (0 vs 1)",
+    );
+
+    let test = || Ok(ensure!(for _ in iter::once(()) {} != ()));
+    assert_err(
+        test,
+        "Condition failed: `for _ in iter::once(()) { } != ()` (() vs ())",
+    );
+
+    let test = || Ok(ensure!(if let stringify!(x) = "x" { 0 } else { 1 } == 1));
+    assert_err(
+        test,
+        "Condition failed: `if let stringify!(x) = \"x\" { 0 } else { 1 } == 1` (0 vs 1)",
+    );
+}