initial piece ripped out of browser-builtins

Author: James Halliday

index.js

@@ -0,0 +1,209 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// 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
+// relative and absolute paths)
+function normalizeArray(parts, allowAboveRoot) {
+  // if the path tries to go above the root, `up` ends up > 0
+  var up = 0;
+  for (var i = parts.length - 1; i >= 0; i--) {
+    var last = parts[i];
+    if (last === '.') {
+      parts.splice(i, 1);
+    } else if (last === '..') {
+      parts.splice(i, 1);
+      up++;
+    } else if (up) {
+      parts.splice(i, 1);
+      up--;
+    }
+  }
+
+  // if the path is allowed to go above the root, restore leading ..s
+  if (allowAboveRoot) {
+    for (; up--; up) {
+      parts.unshift('..');
+    }
+  }
+
+  return parts;
+}
+
+// Split a filename into [root, dir, basename, ext], unix version
+// 'root' is just a slash, or nothing.
+var splitPathRe =
+    /^(\/?|)([\s\S]*?)((?:\.{1,2}|[^\/]+?|)(\.[^.\/]*|))(?:[\/]*)$/;
+var splitPath = function(filename) {
+  return splitPathRe.exec(filename).slice(1);
+};
+
+// path.resolve([from ...], to)
+// posix version
+exports.resolve = function() {
+  var resolvedPath = '',
+      resolvedAbsolute = false;
+
+  for (var i = arguments.length - 1; i >= -1 && !resolvedAbsolute; i--) {
+    var path = (i >= 0) ? arguments[i] : process.cwd();
+
+    // Skip empty and invalid entries
+    if (!util.isString(path)) {
+      throw new TypeError('Arguments to path.resolve must be strings');
+    } else if (!path) {
+      continue;
+    }
+
+    resolvedPath = path + '/' + resolvedPath;
+    resolvedAbsolute = path.charAt(0) === '/';
+  }
+
+  // At this point the path should be resolved to a full absolute path, but
+  // handle relative paths to be safe (might happen when process.cwd() fails)
+
+  // Normalize the path
+  resolvedPath = normalizeArray(shims.filter(resolvedPath.split('/'), function(p) {
+    return !!p;
+  }), !resolvedAbsolute).join('/');
+
+  return ((resolvedAbsolute ? '/' : '') + resolvedPath) || '.';
+};
+
+// path.normalize(path)
+// posix version
+exports.normalize = function(path) {
+  var isAbsolute = exports.isAbsolute(path),
+      trailingSlash = shims.substr(path, -1) === '/';
+
+  // Normalize the path
+  path = normalizeArray(shims.filter(path.split('/'), function(p) {
+    return !!p;
+  }), !isAbsolute).join('/');
+
+  if (!path && !isAbsolute) {
+    path = '.';
+  }
+  if (path && trailingSlash) {
+    path += '/';
+  }
+
+  return (isAbsolute ? '/' : '') + path;
+};
+
+// posix version
+exports.isAbsolute = function(path) {
+  return path.charAt(0) === '/';
+};
+
+// 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)) {
+      throw new TypeError('Arguments to path.join must be strings');
+    }
+    return p;
+  }).join('/'));
+};
+
+
+// path.relative(from, to)
+// posix version
+exports.relative = function(from, to) {
+  from = exports.resolve(from).substr(1);
+  to = exports.resolve(to).substr(1);
+
+  function trim(arr) {
+    var start = 0;
+    for (; start < arr.length; start++) {
+      if (arr[start] !== '') break;
+    }
+
+    var end = arr.length - 1;
+    for (; end >= 0; end--) {
+      if (arr[end] !== '') break;
+    }
+
+    if (start > end) return [];
+    return arr.slice(start, end - start + 1);
+  }
+
+  var fromParts = trim(from.split('/'));
+  var toParts = trim(to.split('/'));
+
+  var length = Math.min(fromParts.length, toParts.length);
+  var samePartsLength = length;
+  for (var i = 0; i < length; i++) {
+    if (fromParts[i] !== toParts[i]) {
+      samePartsLength = i;
+      break;
+    }
+  }
+
+  var outputParts = [];
+  for (var i = samePartsLength; i < fromParts.length; i++) {
+    outputParts.push('..');
+  }
+
+  outputParts = outputParts.concat(toParts.slice(samePartsLength));
+
+  return outputParts.join('/');
+};
+
+exports.sep = '/';
+exports.delimiter = ':';
+
+exports.dirname = function(path) {
+  var result = splitPath(path),
+      root = result[0],
+      dir = result[1];
+
+  if (!root && !dir) {
+    // No dirname whatsoever
+    return '.';
+  }
+
+  if (dir) {
+    // It has a dirname, strip trailing slash
+    dir = dir.substr(0, dir.length - 1);
+  }
+
+  return root + dir;
+};
+
+
+exports.basename = function(path, ext) {
+  var f = splitPath(path)[2];
+  // TODO: make this comparison case-insensitive on windows?
+  if (ext && f.substr(-1 * ext.length) === ext) {
+    f = f.substr(0, f.length - ext.length);
+  }
+  return f;
+};
+
+
+exports.extname = function(path) {
+  return splitPath(path)[3];
+};