rustdoc: allow searches to match against both type and name

repurposes existing syntax that previously had a nonsese meaning.

now `fn:add, u8 -> u8` searches for fn items with "add" in the name,
that take a `u8` argument and return a `u8`.

the kind is included in anticipation that type based searches will
soon work on items other than functions and methods.

fixes #131130

Author: lolbinarycat

src/librustdoc/html/static/js/externs.js

@@ -36,8 +36,8 @@ let ParserState;
  *     userQuery: string,
  *     typeFilter: number,
  *     elems: Array<QueryElement>,
- *     args: Array<QueryElement>,
  *     returned: Array<QueryElement>,
+ *     extraNameElem: QueryElement | null,
  *     foundElems: number,
  *     totalElems: number,
  *     literalSearch: boolean,

src/librustdoc/html/static/js/search.js

@@ -52,6 +52,12 @@ const itemTypes = [
 // used for special search precedence
 const TY_GENERIC = itemTypes.indexOf("generic");
 const TY_IMPORT = itemTypes.indexOf("import");
+// used for isType
+const TY_STRUCT = itemTypes.indexOf("struct");
+const TY_ENUM = itemTypes.indexOf("enum");
+const TY_UNION = itemTypes.indexOf("union");
+const TY_PRIMATIVE = itemTypes.indexOf("primative");
+const TY_FOREIGN_TYPE = itemTypes.indexOf("foreigntype");
 const ROOT_PATH = typeof window !== "undefined" ? window.rootPath : "../";
 
 // Hard limit on how deep to recurse into generics when doing type-driven search.
@@ -239,6 +245,18 @@ function prevIs(parserState, lookingFor) {
     return false;
 }
 
+function isType(ty) {
+    return ty === TY_STRUCT || ty === TY_ENUM || ty === TY_UNION ||
+        ty === TY_PRIMATIVE || ty === TY_FOREIGN_TYPE || ty === -1;
+}
+
+/**
+ * This function removes any queryElem that cannot be a function argument.
+ */
+function filterOnlyTypes(elems) {
+    return elems.filter(elem => isType(elem.typeFilter));
+}
+
 /**
  * Returns `true` if the last element in the `elems` argument has generics.
  *
@@ -1800,6 +1818,8 @@ class DocSearch {
                 correction: null,
                 proposeCorrectionFrom: null,
                 proposeCorrectionTo: null,
+                // used for type-and-name searches
+                extraNameElem: null,
                 // bloom filter build from type ids
                 typeFingerprint: new Uint32Array(4),
             };
@@ -1932,6 +1952,17 @@ class DocSearch {
             query.literalSearch = parserState.totalElems > 1;
         }
         query.foundElems = query.elems.length + query.returned.length;
+        if (query.returned.length > 0 || query.elems.length > 1) {
+            for (const elem of query.elems) {
+                if (!isType(elem.typeFilter)) {
+                    query.extraNameElem = elem;
+                    query.elems = filterOnlyTypes(query.elems);
+                    query.hasReturnArrow = true;
+                    console.log(query.elems);
+                    break;
+                }
+            }
+        }
         query.totalElems = parserState.totalElems;
         return query;
     }
@@ -3047,7 +3078,7 @@ class DocSearch {
          * @param {integer} pos      - Position in the `searchIndex`.
          * @param {Object} results
          */
-        function handleArgs(row, pos, results) {
+        function handleArgs(row, pos, results, maxEditDistance) {
             if (!row || (filterCrates !== null && row.crate !== filterCrates) || !row.type) {
                 return;
             }
@@ -3084,8 +3115,26 @@ class DocSearch {
                 return;
             }
 
+            let name_dist = 0;
+            let path_dist = tfpDist;
+            const name_elem = parsedQuery.extraNameElem;
+            if (name_elem !== null) {
+                if (!typePassesFilter(name_elem.typeFilter, row.ty)) {
+                    return;
+                }
+                name_dist = editDistance(
+                    row.normalizedName, name_elem.normalizedPathLast, maxEditDistance);
+                if (row.normalizedName.includes(name_elem.normalizedPathLast)) {
+                    name_dist = name_dist / 3;
+                }
+                if (name_dist > maxEditDistance) {
+                    return;
+                }
+                const real_path_dist = checkPath(name_elem.fullPath, row);
+                path_dist = (path_dist + real_path_dist) / 2;
+            }
             results.max_dist = Math.max(results.max_dist || 0, tfpDist);
-            addIntoResults(results, row.id, pos, 0, tfpDist, 0, Number.MAX_VALUE);
+            addIntoResults(results, row.id, pos, name_dist, path_dist, 0, Number.MAX_VALUE);
         }
 
         /**
@@ -3285,7 +3334,7 @@ class DocSearch {
                 parsedQuery.elems.sort(sortQ);
                 parsedQuery.returned.sort(sortQ);
                 for (let i = 0, nSearchIndex = this.searchIndex.length; i < nSearchIndex; ++i) {
-                    handleArgs(this.searchIndex[i], i, results_others);
+                    handleArgs(this.searchIndex[i], i, results_others, maxEditDistance);
                 }
             }
         };

tests/rustdoc-js-std/type-and-name.js

@@ -0,0 +1,7 @@
+const EXPECTED = {
+    'query': 'method:ascii, char -> bool',
+    'others': [
+        { 'path': 'char', 'name': 'is_ascii_digit' },
+        { 'path': 'char', 'name': 'eq_ignore_ascii_case' },
+    ],
+}