Merge pull request github#19130 from paldepind/rust-type-alias-string

Rust: Implement toString on type aliases and add docs

Author: paldepind

rust/ql/.generated.list

@@ -15,9 +15,12 @@ module Impl {
 
   // the following QLdoc is generated: if you need to edit it, do it in the schema file
   /**
-   * A GenericParamList. For example:
+   * A list of generic parameters. For example:
    * ```rust
-   * todo!()
+   * fn f<A, B>(a: A, b: B) {}
+   * //  ^^^^^^
+   * type Foo<T1, T2> = (T1, T2);
+   * //      ^^^^^^^^
    * ```
    */
   class GenericParamList extends Generated::GenericParamList {

rust/ql/.gitattributes

@@ -1,4 +1,3 @@
-// generated by codegen, remove this comment if you wish to edit this file
 /**
  * This module provides a hand-modifiable wrapper around the generated class `TypeAlias`.
  *
@@ -12,11 +11,27 @@ private import codeql.rust.elements.internal.generated.TypeAlias
  * be referenced directly.
  */
 module Impl {
+  // the following QLdoc is generated: if you need to edit it, do it in the schema file
   /**
-   * A TypeAlias. For example:
+   * A type alias. For example:
    * ```rust
-   * todo!()
+   * type Point = (u8, u8);
+   *
+   * trait Trait {
+   *     type Output;
+   * //  ^^^^^^^^^^^
+   * }
    * ```
    */
-  class TypeAlias extends Generated::TypeAlias { }
+  class TypeAlias extends Generated::TypeAlias {
+    override string toStringImpl() { result = concat(int i | | this.toStringPart(i) order by i) }
+
+    private string toStringPart(int index) {
+      index = 0 and result = "type "
+      or
+      index = 1 and result = this.getName().getText()
+      or
+      index = 2 and result = this.getGenericParamList().toAbbreviatedString()
+    }
+  }
 }