inline the shims for tinier bundles

Author: James Halliday

index.js

@@ -19,9 +19,6 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
-var util = require('util');
-var shims = require('_shims');
-
 // resolves . and .. elements in a path array with directory names there
 // must be no slashes, empty elements, or device names (c:\) in the array
 // (so also no leading and trailing slashes - it does not distinguish
@@ -70,7 +67,7 @@ exports.resolve = function() {
     var path = (i >= 0) ? arguments[i] : process.cwd();
 
     // Skip empty and invalid entries
-    if (!util.isString(path)) {
+    if (typeof path !== 'string') {
       throw new TypeError('Arguments to path.resolve must be strings');
     } else if (!path) {
       continue;
@@ -84,7 +81,7 @@ exports.resolve = function() {
   // handle relative paths to be safe (might happen when process.cwd() fails)
 
   // Normalize the path
-  resolvedPath = normalizeArray(shims.filter(resolvedPath.split('/'), function(p) {
+  resolvedPath = normalizeArray(filter(resolvedPath.split('/'), function(p) {
     return !!p;
   }), !resolvedAbsolute).join('/');
 
@@ -95,10 +92,10 @@ exports.resolve = function() {
 // posix version
 exports.normalize = function(path) {
   var isAbsolute = exports.isAbsolute(path),
-      trailingSlash = shims.substr(path, -1) === '/';
+      trailingSlash = substr(path, -1) === '/';
 
   // Normalize the path
-  path = normalizeArray(shims.filter(path.split('/'), function(p) {
+  path = normalizeArray(filter(path.split('/'), function(p) {
     return !!p;
   }), !isAbsolute).join('/');
 
@@ -120,8 +117,8 @@ exports.isAbsolute = function(path) {
 // posix version
 exports.join = function() {
   var paths = Array.prototype.slice.call(arguments, 0);
-  return exports.normalize(shims.filter(paths, function(p, index) {
-    if (!util.isString(p)) {
+  return exports.normalize(filter(paths, function(p, index) {
+    if (typeof p !== 'string') {
       throw new TypeError('Arguments to path.join must be strings');
     }
     return p;
@@ -207,3 +204,21 @@ exports.basename = function(path, ext) {
 exports.extname = function(path) {
   return splitPath(path)[3];
 };
+
+function filter (xs, f) {
+    if (xs.filter) return xs.filter(f);
+    var res = [];
+    for (var i = 0; i < xs.length; i++) {
+        if (f(xs[i], i, xs)) res.push(xs[i]);
+    }
+    return res;
+}
+
+// String.prototype.substr - negative index don't work in IE8
+var substr = 'ab'.substr(-1) === 'b'
+    ? function (str, start, len) { return str.substr(start, len) }
+    : function (str, start, len) {
+        if (start < 0) start = str.length + start;
+        return str.substr(start, len);
+    }
+;