balanced-match - npm Package Compare versions

Comparing version 0.2.1 to 0.3.0

index.js

 module.exports = balanced;
 function balanced(a, b, str) {
-  var bal = 0;
-  var m = {};
-  var ended = false;
+  var r = range(a, b, str);
 
-  for (var i = 0; i < str.length; i++) {
-    if (a == str.substr(i, a.length)) {
-      if (!('start' in m)) m.start = i;
-      bal++;
-    }
-    else if (b == str.substr(i, b.length) && 'start' in m) {
-      ended = true;
-      bal--;
-      if (!bal) {
-        m.end = i;
-        m.pre = str.substr(0, m.start);
-        m.body = (m.end - m.start > 1)
-          ? str.substring(m.start + a.length, m.end)
-          : '';
-        m.post = str.slice(m.end + b.length);
-        return m;
+  return r && {
+    start: r[0],
+    end: r[1],
+    pre: str.slice(0, r[0]),
+    body: str.slice(r[0] + a.length, r[1]),
+    post: str.slice(r[1] + b.length)
+  };
+}
+
+balanced.range = range;
+function range(a, b, str) {
+  var begs, beg, left, right, result;
+  var ai = str.indexOf(a);
+  var bi = str.indexOf(b, ai + 1);
+  var i = ai;
+
+  if (ai >= 0 && bi > 0) {
+    begs = [];
+    left = str.length;
+
+    while (i < str.length && i >= 0 && ! result) {
+      if (i == ai) {
+        begs.push(i);
+        ai = str.indexOf(a, i + 1);
+      } else if (begs.length == 1) {
+        result = [ begs.pop(), bi ];
+      } else {
+        beg = begs.pop();
+        if (beg < left) {
+          left = beg;
+          right = bi;
+        }
+
+        bi = str.indexOf(b, i + 1);
       }
+
+      i = ai < bi && ai >= 0 ? ai : bi;
     }
-  }
 
-  // if we opened more than we closed, find the one we closed
-  if (bal && ended) {
-    var start = m.start + a.length;
-    m = balanced(a, b, str.substr(start));
-    if (m) {
-      m.start += start;
-      m.end += start;
-      m.pre = str.slice(0, start) + m.pre;
+    if (begs.length) {
+      result = [ left, right ];
     }
-    return m;
   }
+
+  return result;
 }

package.json

 {
   "name": "balanced-match",
   "description": "Match balanced character pairs, like \"{\" and \"}\"",
-  "version": "0.2.1",
+  "version": "0.3.0",
   "repository": {
@@ -16,3 +16,3 @@ "type": "git",
   "devDependencies": {
-    "tape": "~1.1.1"
+    "tape": "~4.2.2"
   },
@@ -19,0 +19,0 @@ "keywords": [

README.md

@@ -50,2 +50,11 @@ # balanced-match
 
+### var r = balanced.range(a, b, str)
+
+For the first non-nested matching pair of `a` and `b` in `str`, return an
+array with indexes: `[ <a index>, <b index> ]`.
+
+If there's no match, `undefined` will be returned.
+
+If the `str` contains more `a` than `b` / there are unmatched pairs, the first match that was closed will be used. For example, `{{a}` will match `[ 1, 3 ]`.
+
 ## Installation
@@ -52,0 +61,0 @@

test/balanced.js

@@ -55,3 +55,31 @@ var test = require('tape');
   });
+  t.deepEqual(balanced('{{', '}}', 'pre{{{in}}}post'), {
+    start: 3,
+    end: 9,
+    pre: 'pre',
+    body: '{in}',
+    post: 'post'
+  });
+  t.deepEqual(balanced('{{{', '}}', 'pre{{{in}}}post'), {
+    start: 3,
+    end: 8,
+    pre: 'pre',
+    body: 'in',
+    post: '}post'
+  });
+  t.deepEqual(balanced('{', '}', 'pre{{first}in{second}post'), {
+    start: 4,
+    end: 10,
+    pre: 'pre{',
+    body: 'first',
+    post: 'in{second}post'
+  });
+  t.deepEqual(balanced('<?', '?>', 'pre<?>post'), {
+    start: 3,
+    end: 4,
+    pre: 'pre',
+    body: '',
+    post: 'post'
+  });
   t.end();
 });

No alert changes

Improved metrics

Total package byte prevSize

8250

14.3%

Lines of code

128

36.17%

Number of lines in readme file

90

11.11%

No dependency changes