tags support

Author: obenjiro

src/speg_parser.js

@@ -82,14 +82,27 @@ function parsing_ordered_choice() {
 }
 
 function parsing_sub_expression() {
-    return rd.action('parsing_sub_expression', rd.ordered_choice([
-        parsing_not_predicate(),
-        parsing_and_predicate(),
-        parsing_optional(),
-        parsing_one_or_more(),
-        parsing_zero_or_more(),
-        parsing_group(),
-        parsing_atomic_expression()
+    return rd.action('parsing_sub_expression', rd.sequence([
+        rd.zero_or_more(rd.sequence([
+            tag(),
+            rd.string(':')
+        ])),
+        rd.ordered_choice([
+            parsing_not_predicate(),
+            parsing_and_predicate(),
+            parsing_optional(),
+            parsing_one_or_more(),
+            parsing_zero_or_more(),
+            parsing_group(),
+            parsing_atomic_expression()
+        ])
+    ]));
+}
+
+function tag() {
+    return rd.action('noop', rd.sequence([
+        rd.regex_char('[a-zA-Z_]'),
+        rd.zero_or_more(rd.regex_char('[a-zA-Z_0-9]'))
     ]));
 }
 

src/speg_visitor.js

@@ -61,7 +61,23 @@ SPEG_actions.prototype.parsing_ordered_choice = function(node) {
 };
 
 SPEG_actions.prototype.parsing_sub_expression = function(node) {
-    return node.children[0];
+    return function() {
+        var result = node.children[1].children[0].apply(this, arguments);
+        if (result) {
+            var tags = node.children[0].children.map(function(tag_node){
+                return tag_node.children[0].match;
+            });
+            if (tags.length > 0) {
+                if (result.tags) {
+                    result.tags = tags.concat(result.tags);
+                } else {
+                    result.tags = tags;
+                }
+            }
+        }
+        return result;
+    }
+    return node.children[1].children[0];
 };
 
 SPEG_actions.prototype.parsing_group = function(node) {

test/speg_fixtures/tag.peg

@@ -0,0 +1,3 @@
+GRAMMAR test
+
+a -> tag:"A";

test/speg_fixtures/tag.peg.json

@@ -0,0 +1,9 @@
+{
+  "type": "string", 
+  "start_position": 0, 
+  "match": "A", 
+  "tags": [
+    "tag"
+  ],
+  "end_position": 1
+}

test/speg_fixtures/tag.peg.txt

@@ -0,0 +1 @@
+A

test/speg_fixtures/tags.peg

@@ -0,0 +1,5 @@
+GRAMMAR test
+
+a -> tag1:tag2:b ctag:c;
+b -> c;
+c -> last:"A";

test/speg_fixtures/tags.peg.json

@@ -0,0 +1,29 @@
+{
+  "type": "sequence", 
+  "start_position": 0, 
+  "match": "AA",
+  "children": [
+      {
+        "end_position": 1,
+        "match": "A",
+        "start_position": 0,
+        "tags": [
+          "tag1",
+          "tag2",
+          "last"
+        ],
+        "type": "string"
+      },
+      {
+        "end_position": 2,
+        "match": "A",
+        "start_position": 1,
+        "tags": [
+          "ctag",
+          "last"
+        ],
+        "type": "string"
+      }
+  ],
+  "end_position": 2
+}

test/speg_fixtures/tags.peg.txt

@@ -0,0 +1 @@
+AA

test/speg_grammar_fixtures/valid/tag.peg

@@ -0,0 +1,3 @@
+GRAMMAR tag
+
+tag -> tag:"tag";

test/speg_grammar_fixtures/valid/tags_url.peg

@@ -0,0 +1,11 @@
+GRAMMAR url
+
+url       ->  scheme "://" host pathname search hash?;
+scheme    ->  "http" "s"?;
+host      ->  hostname port?;
+hostname  ->  segment ("." segment)*;
+segment   ->  [a-z0-9-]+;
+port      ->  ":" [0-9]+;
+pathname  ->  "/" [^ ?]*;
+search    ->  ("?" [^ #]*)?;
+hash      ->  "#" [^ ]*;