cleanup: leverage Itertools::try_collect() instead of turbofish

It still requires return type annotation in some places, but should be easier
to type than ::<Result<...

https://docs.rs/itertools/latest/itertools/trait.Itertools.html#method.try_collect

lib/src/repo_path.rs

@@ -98,7 +98,7 @@ impl RepoPath {
                 Component::Normal(a) => Ok(RepoPathComponent::from(a.to_str().unwrap())),
                 _ => Err(FsPathParseError::InputNotInRepo(input.to_string())),
             })
-            .collect::<Result<Vec<_>, _>>()?;
+            .try_collect()?;
         Ok(RepoPath::from_components(components))
     }
 

lib/src/revset.rs

@@ -800,10 +800,10 @@ fn parse_function_expression(
         // Resolve arguments in the current scope, and pass them in to the alias
         // expansion scope.
         let arguments_span = arguments_pair.as_span();
-        let args = arguments_pair
+        let args: Vec<_> = arguments_pair
             .into_inner()
             .map(|arg| parse_expression_rule(arg.into_inner(), state))
-            .collect::<Result<Vec<_>, RevsetParseError>>()?;
+            .try_collect()?;
         if params.len() == args.len() {
             let locals = params.iter().map(|s| s.as_str()).zip(args).collect();
             state.with_alias_expanding(id, &locals, primary_span, |state| {
@@ -934,9 +934,9 @@ fn parse_builtin_function(
         "file" => {
             if let Some(ctx) = state.workspace_ctx {
                 let arguments_span = arguments_pair.as_span();
-                let paths = arguments_pair
+                let paths: Vec<_> = arguments_pair
                     .into_inner()
-                    .map(|arg| {
+                    .map(|arg| -> Result<_, RevsetParseError> {
                         let span = arg.as_span();
                         let needle = parse_function_argument_to_string(name, arg, state)?;
                         let path = RepoPath::parse_fs_path(ctx.cwd, ctx.workspace_root, &needle)
@@ -948,7 +948,7 @@ fn parse_builtin_function(
                             })?;
                         Ok(path)
                     })
-                    .collect::<Result<Vec<_>, RevsetParseError>>()?;
+                    .try_collect()?;
                 if paths.is_empty() {
                     Err(RevsetParseError::with_span(
                         RevsetParseErrorKind::InvalidFunctionArguments {

src/cli_util.rs

@@ -563,10 +563,10 @@ impl WorkspaceCommandHelper {
             Ok(Box::new(EverythingMatcher))
         } else {
             // TODO: Add support for globs and other formats
-            let paths = values
+            let paths: Vec<_> = values
                 .iter()
                 .map(|v| self.parse_file_path(v))
-                .collect::<Result<Vec<_>, _>>()?;
+                .try_collect()?;
             Ok(Box::new(PrefixMatcher::new(&paths)))
         }
     }
@@ -617,7 +617,7 @@ impl WorkspaceCommandHelper {
             ))),
             (Some(commit0), Some(commit1)) => {
                 let mut iter = [commit0, commit1].into_iter().chain(iter);
-                let commits = iter.by_ref().take(5).collect::<Result<Vec<_>, _>>()?;
+                let commits: Vec<_> = iter.by_ref().take(5).try_collect()?;
                 let elided = iter.next().is_some();
                 let hint = format!(
                     "The revset resolved to these revisions:\n{commits}{ellipsis}",

src/commands.rs

@@ -27,7 +27,7 @@ use chrono::{FixedOffset, LocalResult, TimeZone, Utc};
 use clap::builder::NonEmptyStringValueParser;
 use clap::{ArgAction, ArgGroup, ArgMatches, CommandFactory, FromArgMatches, Subcommand};
 use itertools::Itertools;
-use jujutsu_lib::backend::{BackendError, CommitId, Timestamp, TreeValue};
+use jujutsu_lib::backend::{CommitId, Timestamp, TreeValue};
 use jujutsu_lib::commit::Commit;
 use jujutsu_lib::commit_builder::CommitBuilder;
 use jujutsu_lib::dag_walk::topo_order_reverse;
@@ -2702,18 +2702,18 @@ fn rebase_revision(
                 .parents()
                 .ancestors(),
         );
-        let new_child_parents: Result<Vec<Commit>, BackendError> = workspace_command
+        let new_child_parents: Vec<Commit> = workspace_command
             .evaluate_revset(&new_child_parents_expression)
             .unwrap()
             .iter()
             .commits(store)
-            .collect();
+            .try_collect()?;
 
         rebase_commit(
             ui.settings(),
             tx.mut_repo(),
             &child_commit,
-            &new_child_parents?,
+            &new_child_parents,
         );
         num_rebased_descendants += 1;
     }
@@ -3472,16 +3472,16 @@ fn cmd_sparse(ui: &mut Ui, command: &CommandHelper, args: &SparseArgs) -> Result
         }
     } else {
         let mut workspace_command = command.workspace_helper(ui)?;
-        let paths_to_add = args
+        let paths_to_add: Vec<_> = args
             .add
             .iter()
             .map(|v| workspace_command.parse_file_path(v))
-            .collect::<Result<Vec<_>, _>>()?;
+            .try_collect()?;
-        let paths_to_remove = args
+        let paths_to_remove: Vec<_> = args
             .remove
             .iter()
             .map(|v| workspace_command.parse_file_path(v))
-            .collect::<Result<Vec<_>, _>>()?;
+            .try_collect()?;
         let (mut locked_wc, _wc_commit) = workspace_command.start_working_copy_mutation()?;
         let mut new_patterns = HashSet::new();
         if args.reset {

src/diff_edit.rs

@@ -212,9 +212,9 @@ pub fn run_mergetool(
         // The default case below should never actually trigger, but we support it just in case
         // resolving the root path ever makes sense.
         .unwrap_or_default();
-    let paths: Result<HashMap<&str, _>, ConflictResolveError> = files
+    let paths: HashMap<&str, _> = files
         .iter()
-        .map(|(role, contents)| {
+        .map(|(role, contents)| -> Result<_, ConflictResolveError> {
             let path = temp_dir.path().join(format!("{role}{suffix}"));
             std::fs::write(&path, contents).map_err(ExternalToolError::SetUpDirError)?;
             if *role != "output" {
@@ -223,8 +223,7 @@ pub fn run_mergetool(
             }
             Ok((*role, path))
         })
-        .collect();
+        .try_collect()?;
-    let paths = paths?;
 
     let args = interpolate_mergetool_filename_patterns(&editor.merge_args, &paths);
     let args_str = args