Omit default parameter types

crates/ra_hir_ty/src/display.rs

@@ -9,7 +9,7 @@ pub struct HirFormatter<'a, 'b, DB> {
     fmt: &'a mut fmt::Formatter<'b>,
     buf: String,
     curr_size: usize,
-    max_size: Option<usize>,
+    truncate_options: Option<&'a TruncateOptions>,
 }
 
 pub trait HirDisplay {
@@ -25,12 +25,12 @@ pub trait HirDisplay {
     fn display_truncated<'a, DB>(
         &'a self,
         db: &'a DB,
-        max_size: Option<usize>,
+        truncate_options: &'a TruncateOptions,
     ) -> HirDisplayWrapper<'a, DB, Self>
     where
         Self: Sized,
     {
-        HirDisplayWrapper(db, self, max_size)
+        HirDisplayWrapper(db, self, Some(truncate_options))
     }
 }
 
@@ -66,15 +66,24 @@ where
     }
 
     pub fn should_truncate(&self) -> bool {
-        if let Some(max_size) = self.max_size {
+        if let Some(max_size) = self.truncate_options.and_then(|options| options.max_length) {
             self.curr_size >= max_size
         } else {
             false
         }
     }
+
+    pub fn should_display_default_types(&self) -> bool {
+        self.truncate_options.map(|options| options.show_default_types).unwrap_or(true)
+    }
 }
 
-pub struct HirDisplayWrapper<'a, DB, T>(&'a DB, &'a T, Option<usize>);
+pub struct TruncateOptions {
+    pub max_length: Option<usize>,
+    pub show_default_types: bool,
+}
+
+pub struct HirDisplayWrapper<'a, DB, T>(&'a DB, &'a T, Option<&'a TruncateOptions>);
 
 impl<'a, DB, T> fmt::Display for HirDisplayWrapper<'a, DB, T>
 where
@@ -87,7 +96,7 @@ where
             fmt: f,
             buf: String::with_capacity(20),
             curr_size: 0,
-            max_size: self.2,
+            truncate_options: self.2,
         })
     }
 }