Adding named group capture

spec/parser/javascript/subexp_spec.js

@@ -13,6 +13,9 @@ describe('parser/javascript/subexp.js', function() {
     '(test)': {
       regexp: jasmine.objectContaining({ textValue: 'test' })
     },
+    '(?<name>test)': {
+      regexp: jasmine.objectContaining({ textValue: 'test' })
+    },
     '(?=test)': {
       regexp: jasmine.objectContaining({ textValue: 'test' })
     },
@@ -95,6 +98,10 @@ describe('parser/javascript/subexp.js', function() {
         label: 'group #1',
         groupCounter: 2
       },
+      '(?<name>test)': {
+        label: 'group \'name\'',
+        groupCounter: 1
+      },
       '(?=test)': {
         label: 'positive lookahead',
         groupCounter: 1

src/js/parser/javascript/grammar.peg

@@ -11,7 +11,10 @@ grammar JavascriptRegexp
   repeat_spec <- ( "{" min:[0-9]+ "," max:[0-9]+ "}"
                  / "{" min:[0-9]+ ",}"
                  / "{" exact:[0-9]+ "}" ) <RepeatSpec>
-  subexp <- "(" capture:( "?:" / "?=" / "?!" )? regexp ")" <Subexp>
+  subexp <- "(" capture:( "?<" groupname:name ">" / "?:" / "?=" / "?!" )? regexp ")" <Subexp>
+  name <- alpha (alpha / numeric)*
+  alpha <- [a-zA-Z]
+  numeric <- [0-9]
   charset <- "[" invert:"^"? parts:( charset_range / charset_terminal )* "]" <Charset>
   charset_range <- first:charset_range_terminal "-" last:charset_range_terminal <CharsetRange>
   charset_terminal <- charset_escape <CharsetEscape>

src/js/parser/javascript/subexp.js

@@ -48,6 +48,10 @@ export default {
   label() {
     if (_.has(this.labelMap, this.properties.capture.textValue)) {
       return this.labelMap[this.properties.capture.textValue];
+    } else if (this.properties.capture !== undefined
+      && this.properties.capture.properties !== undefined
+      && this.properties.capture.properties.groupname) {
+      return `group '${this.properties.capture.properties.groupname.textValue}'`;
     } else {
       return `group #${this.state.groupCounter++}`;
     }