gf-core/src/runtime/haskell

PGF2

This is a Haskell binding to the PGF runtime written in C.

The exposed modules are:

• PGF2: a user API similar to Python and Java APIs
• PGF2.Transactions: an interface for modifying an existing grammar at runtime

How to compile

Important: You must have the C runtime already installed and available on your system. See https://github.com/GrammaticalFramework/gf-core/blob/master/src/runtime/c/INSTALL

Once the runtime is installed, you can install this binding with Cabal:

cabal install pgf2 --extra-lib-dirs=/usr/local/lib

The option extra-lib-dirs is needed if you have installed the C runtime in the default folder /usr/local/lib on Linux. If you instead have configured the C runtime with:

./configure --prefix=/usr

on Linux, or as:

./configure --prefix=<your GHC root directory>/mingw

on Windows, then you don't need the extra-lib-dirs option here.

You can also add the binding to your stack.yaml file:

extra-deps:
  - pgf2
extra-lib-dirs:
  - /usr/local/lib

How to use

Simply import PGF2 in your Haskell program. The Cabal infrastructure will make sure to tell the compiler where to find the relevant modules.

Example

module Main where

import PGF2
import qualified Data.Map as Map

main = do
  pgf <- readPGF "App12.pgf"
  let Just eng = Map.lookup "AppEng" (languages pgf)
  
  -- Parsing
  let res = parse eng (startCat pgf) "this is a small theatre"
  let ParseOk ((tree,prob):rest) = res
  print tree
  
  -- Linearisation
  let Just expr = readExpr "AdjCN (PositA red_A) (UseN theatre_N)"
  let s = linearize eng expr
  print s