2 files changed, 36 insertions, 49 deletions

diff --git a/crates/ra_ide_api/src/display.rs b/crates/ra_ide_api/src/display.rs
index 60fa72f1b..9d9d2097f 100644
--- a/crates/ra_ide_api/src/display.rs
+++ b/crates/ra_ide_api/src/display.rs
@@ -1,5 +1,34 @@
+//! This module contains utilities for rendering turning things into something

+//! that may be used to render in UI.

 use super::*;

 use std::fmt::{self, Display};

+use join_to_string::join;

+

+/// Contains information about a function signature

+#[derive(Debug)]

+pub struct FunctionSignature {

+    /// Optional visibility

+    pub visibility: Option<String>,

+    /// Name of the function

+    pub name: Option<String>,

+    /// Documentation for the function

+    pub doc: Option<Documentation>,

+    /// Generic parameters

+    pub generic_parameters: Vec<String>,

+    /// Parameters of the function

+    pub parameters: Vec<String>,

+    /// Optional return type

+    pub ret_type: Option<String>,

+    /// Where predicates

+    pub where_predicates: Vec<String>,

+}

+

+impl FunctionSignature {

+    pub(crate) fn with_doc_opt(mut self, doc: Option<Documentation>) -> Self {

+        self.doc = doc;

+        self

+    }

+}

 

 impl Display for FunctionSignature {

     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {

@@ -12,14 +41,13 @@ impl Display for FunctionSignature {
         }

 

         if !self.generic_parameters.is_empty() {

-            write!(f, "<")?;

-            write_joined(f, &self.generic_parameters, ", ")?;

-            write!(f, ">")?;

+            join(self.generic_parameters.iter())

+                .separator(", ")

+                .surround_with("<", ">")

+                .to_fmt(f)?;

         }

 

-        write!(f, "(")?;

-        write_joined(f, &self.parameters, ", ")?;

-        write!(f, ")")?;

+        join(self.parameters.iter()).separator(", ").surround_with("(", ")").to_fmt(f)?;

 

         if let Some(t) = &self.ret_type {

             write!(f, " -> {}", t)?;

@@ -27,25 +55,9 @@ impl Display for FunctionSignature {
 

         if !self.where_predicates.is_empty() {

             write!(f, "\nwhere ")?;

-            write_joined(f, &self.where_predicates, ",\n      ")?;

+            join(self.where_predicates.iter()).separator(",\n      ").to_fmt(f)?;

         }

 

         Ok(())

     }

 }

-

-fn write_joined<T: Display>(

-    f: &mut fmt::Formatter,

-    items: impl IntoIterator<Item = T>,

-    sep: &str,

-) -> fmt::Result {

-    let mut first = true;

-    for e in items {

-        if !first {

-            write!(f, "{}", sep)?;

-        }

-        first = false;

-        write!(f, "{}", e)?;

-    }

-    Ok(())

-}

diff --git a/crates/ra_ide_api/src/lib.rs b/crates/ra_ide_api/src/lib.rs
index 7f8f454bc..816bab94f 100644
--- a/crates/ra_ide_api/src/lib.rs
+++ b/crates/ra_ide_api/src/lib.rs
@@ -73,6 +73,7 @@ pub use crate::{
     syntax_highlighting::HighlightedRange,
     structure::{StructureNode, file_structure},
     diagnostics::Severity,
+    display::FunctionSignature,
 };
 
 pub use ra_db::{
@@ -248,32 +249,6 @@ pub struct CallInfo {
     pub active_parameter: Option<usize>,
 }
 
-/// Contains information about a function signature
-#[derive(Debug)]
-pub struct FunctionSignature {
-    /// Optional visibility
-    pub visibility: Option<String>,
-    /// Name of the function
-    pub name: Option<String>,
-    /// Documentation for the function
-    pub doc: Option<Documentation>,
-    /// Generic parameters
-    pub generic_parameters: Vec<String>,
-    /// Parameters of the function
-    pub parameters: Vec<String>,
-    /// Optional return type
-    pub ret_type: Option<String>,
-    /// Where predicates
-    pub where_predicates: Vec<String>,
-}
-
-impl FunctionSignature {
-    pub(crate) fn with_doc_opt(mut self, doc: Option<Documentation>) -> Self {
-        self.doc = doc;
-        self
-    }
-}
-
 /// `AnalysisHost` stores the current state of the world.
 #[derive(Debug, Default)]
 pub struct AnalysisHost {