(chore) split out emitter from TokenTree

highlightjs · Feb 29, 2020 · 1b820c0 · 1b820c0
1 parent b516458
commit 1b820c0
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Showing 2 changed files with 52 additions and 31 deletions.
diff --git a/src/highlight.js b/src/highlight.js
@@ -4,7 +4,7 @@ https://highlightjs.org/
 */
 
 import deepFreeze from './vendor/deep_freeze';
-import TokenTree from './lib/token_tree';
+import TokenTreeEmitter from './lib/token_tree';
 import HTMLRenderer from './lib/html_renderer';
 import * as regex from './lib/regex';
 import * as utils from './lib/utils';
@@ -322,7 +322,7 @@ const HLJS = function(hljs) {
     var top = continuation || language;
     var continuations = {}; // keep continuations for sub-languages
     var result;
-    var emitter = new TokenTree();
+    var emitter = new TokenTreeEmitter();
     processContinuations();
     var mode_buffer = '';
     var relevance = 0;
@@ -395,7 +395,7 @@ const HLJS = function(hljs) {
     languageSubset = languageSubset || options.languages || Object.keys(languages);
     var result = {
       relevance: 0,
-      emitter: new TokenTree(),
+      emitter: new TokenTreeEmitter(),
       value: escape(code)
     };
     var second_best = result;

diff --git a/src/lib/token_tree.js b/src/lib/token_tree.js
@@ -1,4 +1,4 @@
-export default class TokenTree {
+class TokenTree {
   constructor() {
     this.rootNode = { children: [] };
     this.stack = [ this.rootNode ];
@@ -8,31 +8,12 @@ export default class TokenTree {
     return this.stack[this.stack.length - 1];
   }
 
+  get root() { return this.rootNode };
+
   add(node) {
     this.top.children.push(node);
   }
 
-  addKeyword(text, kind) {
-    if (text === "") { return; }
-
-    this.openNode(kind);
-    this.addText(text);
-    this.closeNode();
-  }
-
-  addText(text) {
-    if (text === "") { return; }
-
-    this.add(text);
-  }
-
-  addSublanguage({rootNode}, name) {
-    let node = rootNode;
-    node.kind = name;
-    node.sublanguage = true;
-    this.add(node);
-  }
-
   openNode(kind) {
     let node = { kind, children: [] };
     this.add(node);
@@ -52,12 +33,8 @@ export default class TokenTree {
     return JSON.stringify(this.rootNode, null, 4);
   }
 
-  finalize() {
-    return;
-  }
-
   walk(builder) {
-    return TokenTree._walk(builder, this.rootNode);
+    return this.constructor._walk(builder, this.rootNode);
   }
 
   static _walk(builder, node) {
@@ -73,7 +50,7 @@ export default class TokenTree {
 
   static _collapse(node) {
     if (!node.children) {
-      return
+      return;
     }
     if (node.children.every(el => typeof el === "string")) {
       node.text = node.children.join("")
@@ -86,3 +63,47 @@ export default class TokenTree {
     }
   }
 }
+
+/**
+  Currently this is all private API, but this is the minimal API necessary
+  that an Emitter must implement to fully support the parser.
+
+  API:
+
+  - addKeyword(text, kind)
+  - addText(text)
+  - addSublanguage(emitter, subLangaugeName)
+  - finalize()
+
+*/
+export default class TokenTreeEmitter extends TokenTree {
+  constructor() {
+    super();
+  }
+
+  addKeyword(text, kind) {
+    if (text === "") { return; }
+
+    this.openNode(kind);
+    this.addText(text);
+    this.closeNode();
+  }
+
+  addText(text) {
+    if (text === "") { return; }
+
+    this.add(text);
+  }
+
+  addSublanguage(emitter, name) {
+    let node = emitter.root;
+    node.kind = name;
+    node.sublanguage = true;
+    this.add(node);
+  }
+
+  finalize() {
+    return;
+  }
+
+}