A "concordance" is an alphabetical list of the words present in a text with a count of how often each word appears and citations of where each word appears in the text (e.g., page number). Write a program -- in the programming language of your choice -- that will generate a concordance of an arbitrary text document written in English: the text can be read from stdin, and the program should output the concordance to stdout or a file. For each word, it should print the count and the sorted list of citations, in this case the zero-indexed sentence number in which that word occurs. You may assume that the input contains only spaces, newlines, standard English letters, and standard English punctuation marks.
Just run npm install, tested with node v0.10.33
You could run it by calling cat test/fixtures/base | node index.js
To run tests the usual npm test or make test.
To check that the produced output is the same as the one from the spec you could run diff <(cat test/fixtures/base | node index.js) <(cat test/fixtures/base.expected), if nothing is printed than the calculated concordance is the same.
To run testem so that tests run on file change either run npm run dev or make -s