rustdoc-search: count path edits with separate edit limit

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

@@ -1805,11 +1805,20 @@ function initSearch(rawSearchIndex) {
             return unifyFunctionTypes([row], [elem], whereClause, mgens);
         }
 
-        function checkPath(contains, ty, maxEditDistance) {
+        /**
+         * Compute an "edit distance" that ignores missing path elements.
+         * @param {string[]} contains search query path
+         * @param {Row} ty indexed item
+         * @returns {null|number} edit distance
+         */
+        function checkPath(contains, ty) {
             if (contains.length === 0) {
                 return 0;
             }
-            let ret_dist = maxEditDistance + 1;
+            const maxPathEditDistance = Math.floor(
+                contains.reduce((acc, next) => acc + next.length, 0) / 3
+            );
+            let ret_dist = maxPathEditDistance + 1;
             const path = ty.path.split("::");
 
             if (ty.parent && ty.parent.name) {
@@ -1821,15 +1830,23 @@ function initSearch(rawSearchIndex) {
             pathiter: for (let i = length - clength; i >= 0; i -= 1) {
                 let dist_total = 0;
                 for (let x = 0; x < clength; ++x) {
-                    const dist = editDistance(path[i + x], contains[x], maxEditDistance);
-                    if (dist > maxEditDistance) {
-                        continue pathiter;
+                    const [p, c] = [path[i + x], contains[x]];
+                    if (Math.floor((p.length - c.length) / 3) <= maxPathEditDistance &&
+                        p.indexOf(c) !== -1
+                    ) {
+                        // discount distance on substring match
+                        dist_total += Math.floor((p.length - c.length) / 3);
+                    } else {
+                        const dist = editDistance(p, c, maxPathEditDistance);
+                        if (dist > maxPathEditDistance) {
+                            continue pathiter;
+                        }
+                        dist_total += dist;
                     }
-                    dist_total += dist;
                 }
                 ret_dist = Math.min(ret_dist, Math.round(dist_total / clength));
             }
-            return ret_dist;
+            return ret_dist > maxPathEditDistance ? null : ret_dist;
         }
 
         function typePassesFilter(filter, type) {
@@ -2030,8 +2047,8 @@ function initSearch(rawSearchIndex) {
             }
 
             if (elem.fullPath.length > 1) {
-                path_dist = checkPath(elem.pathWithoutLast, row, maxEditDistance);
-                if (path_dist > maxEditDistance) {
+                path_dist = checkPath(elem.pathWithoutLast, row);
+                if (path_dist === null) {
                     return;
                 }
             }
@@ -2045,7 +2062,7 @@ function initSearch(rawSearchIndex) {
 
             const dist = editDistance(row.normalizedName, elem.normalizedPathLast, maxEditDistance);
 
-            if (index === -1 && dist + path_dist > maxEditDistance) {
+            if (index === -1 && dist > maxEditDistance) {
                 return;
             }
 
@@ -2100,13 +2117,9 @@ function initSearch(rawSearchIndex) {
         }
 
         function innerRunQuery() {
-            let queryLen = 0;
-            for (const elem of parsedQuery.elems) {
-                queryLen += elem.name.length;
-            }
-            for (const elem of parsedQuery.returned) {
-                queryLen += elem.name.length;
-            }
+            const queryLen =
+                parsedQuery.elems.reduce((acc, next) => acc + next.pathLast.length, 0) +
+                parsedQuery.returned.reduce((acc, next) => acc + next.pathLast.length, 0);
             const maxEditDistance = Math.floor(queryLen / 3);
 
             /**

tests/rustdoc-js-std/asrawfd.js

@@ -7,7 +7,6 @@ const EXPECTED = {
         // Validate that type alias methods get the correct path.
         { 'path': 'std::os::fd::AsRawFd', 'name': 'as_raw_fd' },
         { 'path': 'std::os::fd::AsRawFd', 'name': 'as_raw_fd' },
-        { 'path': 'std::os::linux::process::PidFd', 'name': 'as_raw_fd' },
         { 'path': 'std::os::fd::RawFd', 'name': 'as_raw_fd' },
     ],
 };

tests/rustdoc-js-std/path-maxeditdistance.js

@@ -0,0 +1,42 @@
+// exact-check
+const FILTER_CRATE = "std";
+const EXPECTED = [
+    {
+        query: 'vec::intoiterator',
+        others: [
+            // trait std::iter::IntoIterator is not the first result
+            { 'path': 'std::vec', 'name': 'IntoIter' },
+            { 'path': 'std::vec::Vec', 'name': 'into_iter' },
+            { 'path': 'std::vec::Drain', 'name': 'into_iter' },
+            { 'path': 'std::vec::IntoIter', 'name': 'into_iter' },
+            { 'path': 'std::vec::ExtractIf', 'name': 'into_iter' },
+            { 'path': 'std::vec::Splice', 'name': 'into_iter' },
+            { 'path': 'std::collections::VecDeque', 'name': 'into_iter' },
+        ],
+    },
+    {
+        query: 'vec::iter',
+        others: [
+            // std::net::ToSocketAttrs::iter should not show up here
+            { 'path': 'std::vec', 'name': 'IntoIter' },
+            { 'path': 'std::vec::Vec', 'name': 'from_iter' },
+            { 'path': 'std::vec::Vec', 'name': 'into_iter' },
+            { 'path': 'std::vec::Drain', 'name': 'into_iter' },
+            { 'path': 'std::vec::IntoIter', 'name': 'into_iter' },
+            { 'path': 'std::vec::ExtractIf', 'name': 'into_iter' },
+            { 'path': 'std::vec::Splice', 'name': 'into_iter' },
+            { 'path': 'std::collections::VecDeque', 'name': 'iter' },
+            { 'path': 'std::collections::VecDeque', 'name': 'iter_mut' },
+            { 'path': 'std::collections::VecDeque', 'name': 'from_iter' },
+            { 'path': 'std::collections::VecDeque', 'name': 'into_iter' },
+        ],
+    },
+    {
+        query: 'slice::itermut',
+        others: [
+            // std::collections::btree_map::itermut should not show up here
+            { 'path': 'std::slice', 'name': 'IterMut' },
+            { 'path': 'std::slice', 'name': 'iter_mut' },
+        ],
+    },
+];

tests/rustdoc-js-std/path-ordering.js

@@ -1,11 +1,20 @@
-const EXPECTED = {
-    query: 'hashset::insert',
-    others: [
-        // ensure hashset::insert comes first
-        { 'path': 'std::collections::hash_set::HashSet', 'name': 'insert' },
-        { 'path': 'std::collections::hash_set::HashSet', 'name': 'get_or_insert' },
-        { 'path': 'std::collections::hash_set::HashSet', 'name': 'get_or_insert_with' },
-        { 'path': 'std::collections::hash_set::HashSet', 'name': 'get_or_insert_owned' },
-        { 'path': 'std::collections::hash_map::HashMap', 'name': 'insert' },
-    ],
-};
+const EXPECTED = [
+    {
+        query: 'hashset::insert',
+        others: [
+            // ensure hashset::insert comes first
+            { 'path': 'std::collections::hash_set::HashSet', 'name': 'insert' },
+            { 'path': 'std::collections::hash_set::HashSet', 'name': 'get_or_insert' },
+            { 'path': 'std::collections::hash_set::HashSet', 'name': 'get_or_insert_with' },
+            { 'path': 'std::collections::hash_set::HashSet', 'name': 'get_or_insert_owned' },
+        ],
+    },
+    {
+        query: 'hash::insert',
+        others: [
+            // ensure hashset/hashmap::insert come first
+            { 'path': 'std::collections::hash_map::HashMap', 'name': 'insert' },
+            { 'path': 'std::collections::hash_set::HashSet', 'name': 'insert' },
+        ],
+    },
+];

tests/rustdoc-js/exact-match.js

@@ -3,6 +3,5 @@ const EXPECTED = {
     'others': [
         { 'path': 'exact_match::Si', 'name': 'pc' },
         { 'path': 'exact_match::Psi', 'name': 'pc' },
-        { 'path': 'exact_match::Si', 'name': 'pa' },
     ],
 };

tests/rustdoc-js/module-substring.js

@@ -1,7 +1,15 @@
-const EXPECTED = {
-    'query': 'ig::pc',
-    'others': [
-        { 'path': 'module_substring::Sig', 'name': 'pc' },
-        { 'path': 'module_substring::Si', 'name': 'pc' },
-    ],
-};
+const EXPECTED = [
+    {
+        'query': 'ig::pc',
+        'others': [
+            { 'path': 'module_substring::Sig', 'name': 'pc' },
+        ],
+    },
+    {
+        'query': 'si::pc',
+        'others': [
+            { 'path': 'module_substring::Si', 'name': 'pc' },
+            { 'path': 'module_substring::Sig', 'name': 'pc' },
+        ],
+    },
+];

tests/rustdoc-js/path-maxeditdistance.js

@@ -0,0 +1,35 @@
+// exact-check
+
+const EXPECTED = [
+    {
+        'query': 'xxxxxxxxxxx::hocuspocusprestidigitation',
+        // do not match abracadabra::hocuspocusprestidigitation
+        'others': [],
+    },
+    {
+        // exact match
+        'query': 'abracadabra::hocuspocusprestidigitation',
+        'others': [
+            { 'path': 'abracadabra', 'name': 'HocusPocusPrestidigitation' },
+        ],
+    },
+    {
+        // swap br/rb; that's edit distance 2, where maxPathEditDistance = 3 (11 / 3)
+        'query': 'arbacadarba::hocuspocusprestidigitation',
+        'others': [
+            { 'path': 'abracadabra', 'name': 'HocusPocusPrestidigitation' },
+        ],
+    },
+    {
+        // truncate 5 chars, where maxEditDistance = 7 (21 / 3)
+        'query': 'abracadarba::hocusprestidigitation',
+        'others': [
+            { 'path': 'abracadabra', 'name': 'HocusPocusPrestidigitation' },
+        ],
+    },
+    {
+        // truncate 9 chars, where maxEditDistance = 5 (17 / 3)
+        'query': 'abracadarba::hprestidigitation',
+        'others': [],
+    },
+];

tests/rustdoc-js/path-maxeditdistance.rs

@@ -0,0 +1,3 @@
+#![crate_name="abracadabra"]
+
+pub struct HocusPocusPrestidigitation;

tests/rustdoc-js/path-ordering.js

@@ -1,13 +1,13 @@
 // exact-check
 
 const EXPECTED = {
-    'query': 'b::ccccccc',
+    'query': 'bbbbbb::ccccccc',
     'others': [
         // `ccccccc` is an exact match for all three of these.
         // However `b` is a closer match for `bb` than for any
         // of the others, so it ought to go first.
-        { 'path': 'path_ordering::bb', 'name': 'Ccccccc' },
-        { 'path': 'path_ordering::aa', 'name': 'Ccccccc' },
-        { 'path': 'path_ordering::dd', 'name': 'Ccccccc' },
+        { 'path': 'path_ordering::bbbbbb', 'name': 'Ccccccc' },
+        { 'path': 'path_ordering::abbbbb', 'name': 'Ccccccc' },
+        { 'path': 'path_ordering::dbbbbb', 'name': 'Ccccccc' },
     ],
 };

tests/rustdoc-js/path-ordering.rs

@@ -1,9 +1,9 @@
-pub mod dd {
+pub mod dbbbbb {
     pub struct Ccccccc;
 }
-pub mod aa {
+pub mod abbbbb {
     pub struct Ccccccc;
 }
-pub mod bb {
+pub mod bbbbbb {
     pub struct Ccccccc;
 }