rustdoc-search: stop constructing pointless arrays in decode rust-lan…

…g#127379

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

@@ -925,10 +925,9 @@ class VlqHexDecoder {
     }
     // call after consuming `{`
     decodeList() {
-        const cb = "}".charCodeAt(0);
         let c = this.string.charCodeAt(this.offset);
         const ret = [];
-        while (c !== cb) {
+        while (c !== 125) { // 125 = "}"
             ret.push(this.decode());
             c = this.string.charCodeAt(this.offset);
         }
@@ -937,14 +936,13 @@ class VlqHexDecoder {
     }
     // consumes and returns a list or integer
     decode() {
-        const [ob, la] = ["{", "`"].map(c => c.charCodeAt(0));
         let n = 0;
         let c = this.string.charCodeAt(this.offset);
-        if (c === ob) {
+        if (c === 123) { // 123 = "{"
             this.offset += 1;
             return this.decodeList();
         }
-        while (c < la) {
+        while (c < 96) { // 96 = "`"
             n = (n << 4) | (c & 0xF);
             this.offset += 1;
             c = this.string.charCodeAt(this.offset);
@@ -957,15 +955,14 @@ class VlqHexDecoder {
     }
     next() {
         const c = this.string.charCodeAt(this.offset);
-        const [zero, ua, la] = ["0", "@", "`"].map(c => c.charCodeAt(0));
         // sixteen characters after "0" are backref
-        if (c >= zero && c < ua) {
+        if (c >= 48 && c < 64) { // 48 = "0", 64 = "@"
             this.offset += 1;
-            return this.backrefQueue[c - zero];
+            return this.backrefQueue[c - 48];
         }
         // special exception: 0 doesn't use backref encoding
         // it's already one character, and it's always nullish
-        if (c === la) {
+        if (c === 96) { // 96 = "`"
             this.offset += 1;
             return this.cons(0);
         }
@@ -1519,7 +1516,6 @@ class DocSearch {
         };
 
         const searchIndex = [];
-        const charA = "A".charCodeAt(0);
         let currentIndex = 0;
         let id = 0;
 
@@ -1685,7 +1681,7 @@ class DocSearch {
                 // object defined above.
                 const row = {
                     crate,
-                    ty: itemTypes.charCodeAt(i) - charA,
+                    ty: itemTypes.charCodeAt(i) - 65, // 65 = "A"
                     name: itemNames[i],
                     path,
                     descShard,