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The OCaml Handbook: A Complete Guide from First Program to Production Systems by Steve T. Publications is a new release on Leanpub!
Discover the power and elegance of OCaml, from your very first program to production-ready applications. The OCaml Handbook … leanpub.com/theocamlhand...
![defprotocol UnknownImplFor do
def foo(data)
end
defimpl UnknownImplFor,
for: [
Map,
# Unknown # <-- This is the problem
] do
def foo(data), do: data
end
# Compiling 1 file (.ex)
# warning: you are implementing a protocol for Unknown
# but said module is not available. Make sure the module
# name is correct. If Unknown is an optional dependency,
# please wrap the protocol implementation in a
# Code.ensure_loaded?(Unknown) check
# │
# 5 │ defimpl UnknownImplFor,
# │ ~~~~~~~~~~~~~~~~~~~~~~~
# │
# └─ lib/protocol_types.ex:5: (file)](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:jfsigp5qadbh2vzs4h7vprvs/bafkreibprkxnux3gyiepg7iw3bm4flmw4ncucxzbwouesfftf5i5e4ioiq)
![defprotocol IncorrectImpl do
def foo(data)
end
defimpl IncorrectImpl, for: [Map, Range, Bitstring] do
def foo(nil), do: nil # <--- This is the problem
def foo(map), do: map
end
# Compiling 2 files (.ex)
# warning: the 1st pattern in clause will never match:
#
# nil
#
# because it is expected to receive type:
#
# dynamic(%Range{first: term(), last: term(), step: term()})
#
# typing violation found at:
# │
# 6 │ def foo(nil), do: nil
# │ ~~~~~~~~~~~~~~~~~~~~~
# │
# └─ lib/incorrect_dispatch.ex:6: IncorrectDispatch.Range.foo/1](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:jfsigp5qadbh2vzs4h7vprvs/bafkreicymtupuafsywswgkosbgb4k5qd2r5gh4frdpppk5wnbrhchbzexy)
