Handle block comments

voltrevo · Oct 17, 2015 · 8ea06d9 · 8ea06d9
1 parent 25e8744
commit 8ea06d9
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Showing 2 changed files with 84 additions and 24 deletions.
diff --git a/lib/streams/commentFilter.js b/lib/streams/commentFilter.js
@@ -5,6 +5,7 @@ var any = require('../consumers/any.js');
 var constrainAcceptance = require('../consumers/constrainAcceptance.js');
 var constrainValidity = require('../consumers/constrainValidity.js');
 var consumerFilter = require('./consumerFilter.js');
+var defer = require('../util/defer.js');
 var many = require('../consumers/many.js');
 var optional = require('../consumers/optional.js');
 var or = require('../consumers/or.js');
@@ -13,28 +14,55 @@ var single = require('../consumers/single.js');
 var string = require('../consumers/string.js');
 var transform = require('../consumers/transform.js');
 
-module.exports = function(inputStream) {
-  return consumerFilter(
-    or(
-      transform(
-        sequence(
-          string('//'),
-          many(
-            constrainAcceptance(any, function(value) { return value !== '\n'; })
-          ),
-          constrainValidity(
-            optional(single('\n')),
-            function(value) {
-              return value.set;
-            }
-          )
-        ),
-        function() {
-          return '\n';
-        }
-      ),
-      any
+var lineCommentAndNewline = transform(
+  sequence(
+    string('//'),
+    many(
+      constrainAcceptance(any, function(value) { return value !== '\n'; })
     ),
-    inputStream
-  );
+    constrainValidity(
+      optional(single('\n')),
+      function(value) {
+        return value.set;
+      }
+    )
+  ),
+  function() {
+    return '\n';
+  }
+);
+
+var blockCommentAndNext = undefined;
+
+var nextChar = or(
+  lineCommentAndNewline,
+  defer('blockCommentAndNext', function() { return blockCommentAndNext; }),
+  any
+);
+
+var blockComment = sequence(
+  string('/*'),
+  many(or(
+    defer('blockComment', function() { return blockComment; }),
+    constrainAcceptance(any, function(value) { return value !== '*'; }),
+    sequence(
+      single('*'),
+      constrainAcceptance(any, function(value) { return value !== '/'; })
+    )
+  )),
+  string('*/')
+);
+
+blockCommentAndNext = transform(
+  sequence(
+    blockComment,
+    nextChar
+  ),
+  function(value) {
+    return value[1];
+  }
+);
+
+module.exports = function(inputStream) {
+  return consumerFilter(nextChar, inputStream);
 };
diff --git a/test/streams/commentFilter.js b/test/streams/commentFilter.js
@@ -9,7 +9,7 @@ var describeStream = require('../describers/Stream.js');
 var LineStream = require('../../lib/streams/lineStream.js');
 
 describe('commentFilter', function() {
-  it('filters out comments', function() {
+  it('filters out line comments', function() {
     var stream = commentFilter(
       LineStream('test', [
         '// this should be ignored',
@@ -24,6 +24,38 @@ describe('commentFilter', function() {
     assert.equal(stream.next(), 'b');
   });
 
+  it('filters out block comments', function() {
+    var stream = commentFilter(
+      LineStream('test', [
+        '/* this should be ignored */',
+        'a/* more ignored *//* stuff */',
+        'b'
+      ].join('\n'))
+    );
+
+    assert.equal(stream.next(), '\n');
+    assert.equal(stream.next(), 'a');
+    assert.equal(stream.next(), '\n');
+    assert.equal(stream.next(), 'b');
+  });
+
+  it('filters out nested block comments', function() {
+    var stream = commentFilter(
+      LineStream('test', [
+        '/* this should be ignored',
+        '  code = here;',
+        '  ',
+        '  /* this inner block comment shouldn\'t interfere with the outer block comment */',
+        '  more.code = here',
+        '*/',
+        'b'
+      ].join('\n'))
+    );
+
+    assert.equal(stream.next(), '\n');
+    assert.equal(stream.next(), 'b');
+  });
+
   it('hasNext when starting on a comment and there is a newline', function() {
     var stream = commentFilter(
       LineStream('test', '// foobar\n')