Fix npm#1673 Support for regexps in search

doc/cli/search.md

@@ -9,6 +9,9 @@ npm-search(1) -- Search for packages
 
 Search the registry for packages matching the search terms.
 
+If a term starts with `/` and ends with `/`, then it's interpreted as a
+regular expression.
+
 ## CONFIGURATION
 
 ### description

lib/search.js

@@ -108,16 +108,22 @@ function getWords (data) {
 function filterWords (data, args, notArgs) {
   var words = data.words
   for (var i = 0, l = args.length; i < l; i ++) {
-    if (words.indexOf(args[i]) === -1) {
-      return false
-    }
+    if (!match(words, args[i])) return false
   }
   for (var i = 0, l = notArgs.length; i < l; i ++) {
-    if (words.indexOf(notArgs[i]) !== -1) return false
+    if (match(words, notArgs[i])) return false
   }
   return true
 }
 
+function match (words, arg) {
+  if (arg.charAt(0) === "/" && arg.slice(-1) === "/") {
+    arg = new RegExp(arg.substr(1, arg.length - 2))
+    return words.match(arg)
+  }
+  return words.indexOf(arg) !== -1
+}
+
 function prettify (data, args) {
   try {
     var tty = require("tty")
@@ -201,8 +207,17 @@ function addColorMarker (str, arg, i) {
   var m = i % cl + 1
     , markStart = String.fromCharCode(m)
     , markEnd = String.fromCharCode(0)
-    , pieces = str.toLowerCase().split(arg.toLowerCase())
+
+  if (arg.charAt(0) === "/" && arg.slice(-1) === "/") {
+    return str.replace( new RegExp(arg.substr(1, arg.length - 2), "gi")
+                      , function (bit) { return markStart + bit + markEnd } )
+
+  }
+
+  // just a normal string, do the split/map thing
+  var pieces = str.toLowerCase().split(arg.toLowerCase())
     , p = 0
+
   return pieces.map(function (piece, i) {
     piece = str.substr(p, piece.length)
     var mark = markStart
@@ -211,8 +226,8 @@ function addColorMarker (str, arg, i) {
     p += piece.length + arg.length
     return piece + mark
   }).join("")
-  return str.split(arg).join(mark)
 }
+
 function colorize (line) {
   for (var i = 0; i < cl; i ++) {
     var m = i + 1