DO NOT MERGE YET: Drop support for implements statement

README.md

@@ -520,33 +520,6 @@ The fields are as follows:
 * `trivia`: A trivia object.
 * `extAttrs`: An [extended attributes](#extended-attributes) container.
 
-### Implements
-
-An implements definition looks like this:
-
-```JS
-{
-  "type": "implements",
-  "target": "Node",
-  "implements": "EventTarget",
-  "trivia": {
-    "target": "\n\n  ",
-    "implements": " ",
-    "mixin": " ",
-    "termination": ""
-  },
-  "extAttrs": null
-}
-```
-
-The fields are as follows:
-
-* `type`: Always "implements".
-* `target`: The interface that implements another.
-* `implements`: The interface that is being implemented by the target.
-* `trivia`: A trivia object. The field `target` is for the base interface identifier, `implements` for the `implements` keyword, and `mixin` for the mixin identifier.
-* `extAttrs`: An [extended attributes](#extended-attributes) container.
-
 ### Includes
 
 An includes definition looks like this:

lib/webidl2.js

@@ -1100,31 +1100,6 @@
       return ret;
     }
 
-    function implements_() {
-      const start_position = consume_position;
-      const target = consume(ID);
-      if (!target) return;
-      const trivia = { target: target.trivia };
-      const implementsToken = consume("implements");
-      if (implementsToken) {
-        trivia.implements = implementsToken.trivia;
-        const ret = {
-          type: "implements",
-          target: target.value
-        };
-        const imp = consume(ID) || error("Incomplete implements statement");
-        trivia.mixin = imp.trivia;
-        ret.implements = imp.value;
-        ret.trivia = trivia;
-        const termination = consume(";") || error("No terminating ; for implements statement");
-        trivia.termination = termination.trivia;
-        return ret;
-      } else {
-        // rollback
-        unconsume(start_position);
-      }
-    }
-
     function includes() {
       const start_position = consume_position;
       const target = consume(ID);
@@ -1157,7 +1132,6 @@
         dictionary() ||
         enum_() ||
         typedef() ||
-        implements_() ||
         includes() ||
         namespace();
     }

lib/writer.js

@@ -150,10 +150,6 @@
       const ret = extended_attributes(it.extAttrs);
       return `${ret}${it.trivia.base}typedef${type(it.idlType)}${it.trivia.name}${it.name}${it.trivia.termination};`;
     }
-    function implements_(it) {
-      const ret = extended_attributes(it.extAttrs);
-      return `${ret}${it.trivia.target}${it.target}${it.trivia.implements}implements${it.trivia.mixin}${it.implements}${it.trivia.termination};`;
-    }
     function includes(it) {
       const ret = extended_attributes(it.extAttrs);
       return `${ret}${it.trivia.target}${it.target}${it.trivia.includes}includes${it.trivia.mixin}${it.includes}${it.trivia.termination};`;
@@ -195,7 +191,6 @@
       field,
       const: const_,
       typedef,
-      implements: implements_,
       includes,
       callback,
       enum: enum_,

test/invalid/json/implements.json

@@ -0,0 +1,4 @@
+{
+    "message": "Got an error during or right after parsing `interface EventTarget`: Unrecognised tokens",
+    "line": 14
+}