Examples of embedded GF grammars in Python
The grammars use the Python binding available in
https://github.com/GrammaticalFramework/gf-core
see
src/runtime/python/
for installing the Python module pgf, and
src/runtime/c/
for the C runtime library that the bindings are based on. You don't need Haskell to build these.
A general tutorial on the Python bindings can be found in
http://www.grammaticalframework.org/doc/runtime-api.html#python
A guide to GF for Python programmers can be found in
https://daherb.github.io/GF-for-Python-programmers/
Translator
A minimal translator can be found in
This program reads one line of input and translates it from English to Swedish by using MicroGrammar.pgf. Example:
$ echo "the cat is black" | python3 minitranslator.py
katten är svart
A more general version is in
This program reads input line by line, tokenizes it (by a simple tokenizer), and uses an arbitrary pgf and language codes. Example:
$ cat findrawscript.txt | python3 translator.py Draw Fin Eng
# translating with Draw.pgf from DrawFin to DrawEng
draw a small red circle
draw a big yellow square
move the small red circle
remove it
Drawing figures
A minimal drawing program with natural language input can found in
This program reads one line of input in English and converts it to an action of drawing a circle or a square. Example:
$ python3 minidraw.py
draw a circle
The result is this window. The program uses the simple graphics library from
https://mcsp.wartburg.edu/zelle/python/graphics.py
We also presuppose the grammar to be compiled with
make draw
A more complete version (using the same grammar) is in
This program opens a session where it reads input line by line, in a language specified by a language code. Example:
$ python3 draw.py Eng
draw a small red circle
draw a blue square
move it
move the small red circle
The result is this window.
The grammar, Draw.gf, illustrates a few things...
Answering queries
A minimal query answering program with natural language input can found in
This program reads one line of input in English and executes a query, which is either asking if a number is prime, or calculating a sum. Examples:
$ echo "is 143 prime" | python3 miniquery.py
False
$ echo "1 + 2 + 3" | python3 miniquery.py
6
We presuppose the grammar to be compiled with
make query
A more complete version (using the same grammar) is in
This program uses a large grammar with more predicates, operations, and logical forms such as quantifiers. It still reads just one line of input, but allows the language to be specified by a language code. Example:
$ echo "what is the factorial of 12" | python3 query.py Eng
479001600
$ echo "prime numbers between 200 and 300" | python3 query.py Eng
[211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293]
WARNING: ambiguous
$ echo "are all prime numbers odd" | python3 query.py Eng
False
The grammar, Query.gf, illustrates a few things...