replace usages of algo::generate with iter::successors from std

crates/ra_syntax/src/algo.rs

@@ -46,13 +46,3 @@ pub fn non_trivia_sibling(element: SyntaxElement, direction: Direction) -> Optio
 pub fn find_covering_element(root: &SyntaxNode, range: TextRange) -> SyntaxElement {
     root.0.covering_node(range).into()
 }
-
-// Replace with `std::iter::successors` in `1.34.0`
-pub fn generate<T>(seed: Option<T>, step: impl Fn(&T) -> Option<T>) -> impl Iterator<Item = T> {
-    ::itertools::unfold(seed, move |slot| {
-        slot.take().map(|curr| {
-            *slot = step(&curr);
-            curr
-        })
-    })
-}

crates/ra_syntax/src/ptr.rs

@@ -1,8 +1,9 @@
-use std::marker::PhantomData;
-
+use std::{
+    marker::PhantomData,
+    iter::successors,
+};
 use crate::{
     AstNode, SourceFile, SyntaxKind, SyntaxNode, TextRange,
-    algo::generate,
 };
 
 /// A pointer to a syntax node inside a file. It can be used to remember a
@@ -19,7 +20,7 @@ impl SyntaxNodePtr {
     }
 
     pub fn to_node(self, source_file: &SourceFile) -> &SyntaxNode {
-        generate(Some(source_file.syntax()), |&node| {
+        successors(Some(source_file.syntax()), |&node| {
             node.children().find(|it| self.range.is_subrange(&it.range()))
         })
         .find(|it| it.range() == self.range && it.kind() == self.kind)

crates/ra_syntax/src/syntax_node.rs

@@ -10,6 +10,7 @@ use std::{
     fmt::{self, Write},
     any::Any,
     borrow::Borrow,
+    iter::successors,
 };
 
 use ra_parser::ParseError;
@@ -195,7 +196,7 @@ impl SyntaxNode {
     }
 
     pub fn ancestors(&self) -> impl Iterator<Item = &SyntaxNode> {
-        crate::algo::generate(Some(self), |&node| node.parent())
+        successors(Some(self), |&node| node.parent())
     }
 
     pub fn descendants(&self) -> impl Iterator<Item = &SyntaxNode> {
@@ -213,7 +214,7 @@ impl SyntaxNode {
     }
 
     pub fn siblings(&self, direction: Direction) -> impl Iterator<Item = &SyntaxNode> {
-        crate::algo::generate(Some(self), move |&node| match direction {
+        successors(Some(self), move |&node| match direction {
             Direction::Next => node.next_sibling(),
             Direction::Prev => node.prev_sibling(),
         })
@@ -224,7 +225,7 @@ impl SyntaxNode {
         direction: Direction,
     ) -> impl Iterator<Item = SyntaxElement> {
         let me: SyntaxElement = self.into();
-        crate::algo::generate(Some(me), move |el| match direction {
+        successors(Some(me), move |el| match direction {
             Direction::Next => el.next_sibling_or_token(),
             Direction::Prev => el.prev_sibling_or_token(),
         })
@@ -373,7 +374,7 @@ impl<'a> SyntaxToken<'a> {
         direction: Direction,
     ) -> impl Iterator<Item = SyntaxElement<'a>> {
         let me: SyntaxElement = (*self).into();
-        crate::algo::generate(Some(me), move |el| match direction {
+        successors(Some(me), move |el| match direction {
             Direction::Next => el.next_sibling_or_token(),
             Direction::Prev => el.prev_sibling_or_token(),
         })