lemma

lemma is a command-line utility that provides the lemmatized forms (stems) of words in natural language text.

$ echo "Don't be amazed if you see my eyes always wandering." | lemma
do	Do
not	n't
be	be
amaze	amazed
if	if
you	you
see	see
I	my
eye	eyes
always	always
wander	wandering

For more information about natural language processing, check out Chapter 7 of the Flight School Guide to Swift Strings.

Requirements

• macOS 10.12+

Installation

Install lemma with Homebrew using the following command:

$ brew install flight-school/formulae/lemma

Usage

Text can be read from either standard input or file arguments. Tagged words are written to standard output on separate lines.

Reading from Piped Standard Input

$ echo "walking" | lemma
walk	walking

$ echo "gesagt" | lemma
sagen	gesagt

Reading from Standard Input Interactively

$ lemma
This text is being typed into standard input.
this	This
text	text
be	is
be	being
type	typed
into	into
standard	standard
input	input

Reading from a File

$ cat calvino.txt
One reads alone, even in another's presence.

$ lemma calvino.txt
one	One
read	reads
alone	alone
even	even
in	in
another	another
presence	presence

Advanced Usage

lemma can be chained with Unix text processing commands, like cut, sort, uniq, comm, grep sed, and awk.

Filtering Original Text

$ lemma calvino.txt | cut -f1
one
read
alone
even
in
another
presence

Filtering Repeated Lemmas

$ echo "She has to have had a reason" | lemma | awk '!a[$1]++'
she	She
have	has
to	to
a	a
reason	reason

Additional Details

Lemmatized words are written to standard output on separate lines. Each line consists of the lemma followed by a tab (\t), followed by the original word.

lemma uses NLTagger when available, falling back on NSLinguisticTagger for older versions of macOS.

License

MIT

Contact

Mattt (@mattt)