Hello!
I need to write a function which should is supposed to merge multiple
entries with the same
key (out of a sorted key-value-list) into one single entry.
However, I keep getting a pattern matching error.
(For example, for input [('b',[5]),('b',[4]),('b',[1]),('b',[6])]:
"Program error: pattern match failure: kgroup
[('b',[5,4]),('b',[1]),('b',[6])]")
Thank you very much for your help.
kmerge::Eq a => [(a,[b])]->[(a,[b])]
kmerge [] = []
kmerge ((x,[y]):[]) = [(x,[y])]
kmerge ((x,[y]):(u,[v]):xs) | x == u = kmerge ((x,[y,v]):xs)
| otherwise = (x,[y]):(u,[v]):kmerge xs
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