HaskellWorks.Data.BalancedParens.Internal.Broadword.FindClose.Word8

Documentation

findClose :: Word8 -> Count -> Maybe Count

Find the position of the matching close parenthesis.

The position argument and return value is one-based.

If the parenthesis at the input position is an a close, then that is considered the matching close parenthesis.

>>> import HaskellWorks.Data.Bits.BitRead
>>> import Data.Maybe

The following scans for the matching close parenthesis for the open parenthesis at position 1:

>>> findClose (fromJust $ bitRead "10000000") 1
Just 2

>>> findClose (fromJust $ bitRead "11000000") 1
Just 4

>>> findClose (fromJust $ bitRead "11010000") 1
Just 6

The following scans for the matching close parenthesis for the open parenthesis at position 2:

>>> findClose (fromJust $ bitRead "11010000") 2
Just 3

If the input position has a close parenthesis, then that position is returned:

>>> findClose (fromJust $ bitRead "11010000") 3
Just 3

The scan can continue past the end of the input word because every bit after then end of the word is considered to be zero, which is a closing parenthesis:

>>> findClose (fromJust $ bitRead "11111110") 1
Just 14