A-M baby

Task/Inverted-index/CoffeeScript/inverted-index-1.coffee

@@ -0,0 +1,35 @@
+fs = require 'fs'
+
+make_index = (fns) ->
+  # words are indexed by filename and 1-based line numbers
+  index = {}
+  for fn in fns
+    for line, line_num in fs.readFileSync(fn).toString().split '\n'
+      words = get_words line
+      for word in words
+        word = mangle(word)
+        index[word] ||= []
+        index[word].push [fn, line_num+1]
+  index
+
+grep = (index, word) ->
+  console.log "locations for '#{word}':"
+  locations = index[mangle(word)] || []
+  for location in locations
+    [fn, line_num] = location
+    console.log "#{fn}:#{line_num}"
+  console.log "\n"
+
+get_words = (line) ->
+  words = line.replace(/\W/g, ' ').split ' '
+  (word for word in words when word != '')
+
+mangle = (word) ->
+  # avoid conflicts with words like "constructor"
+  '_' + word
+
+do ->
+  fns = (fn for fn in fs.readdirSync('.') when fn.match /\.coffee/)
+  index = make_index(fns)
+  grep index, 'make_index'
+  grep index, 'sort'

Task/Inverted-index/CoffeeScript/inverted-index-2.coffee

@@ -0,0 +1,15 @@
+> coffee inverted_index.coffee
+locations for 'make_index':
+inverted_index.coffee:3
+inverted_index.coffee:33
+inverted_index.coffee:34
+
+
+locations for 'sort':
+anagrams.coffee:8
+derangements.coffee:14
+heap.coffee:34
+heap.coffee:43
+huffman.coffee:81
+inverted_index.coffee:35
+knuth_sample.coffee:12