#!/bin/sh

SIZE=${1:-20}
MODULE=G

# See #17264.
#
# Generates a function with many guards, inspired by Luc Mangaret's S series
#
#   module G where
#
#   data T = A | B
#
#   f :: Int -> (T, T)
#   f n = (A, A)
#
#   g :: ()
#   g
#     | (A, A) <- f 1 = ()
#     | (A, A) <- f 2 = ()
#     | (A, A) <- f 3 = ()
#     | (A, A) <- f 4 = ()
#
# Note how each guard splits into 2 uncovered Deltas

cat > $MODULE.hs <<END
module $MODULE where

data T = A | B

f :: Int -> (T, T)
f _ = (A, A)

g :: ()
g
END

i=1
while test $i -lt $SIZE; do
  echo "  | (A, A) <- f $i = ()" >> $MODULE.hs
  i=$((i+1))
done