Shippai!

Shippai (失敗) is the Japanese word for "failure."

What is it?

Shippai is a Core Erlang transform which changes any match error to a call to erlang:error/2 using the arguments which were given to the current function.

Calls to erlang:error(badrecord) added by the record expansion are also transformed.

Example

-module(t).
-export([t/1]).

t(X) ->
    case X of
        {Y,Z} -> Y + Z
    end.

Without Shippai

$ erlc t.erl
$ erl
1> t:t(foo).
** exception error: no case clause matching foo
     in function  t:t/1 (t.erl, line 5)
1> catch t:t(foo).
{'EXIT',{{case_clause,foo},
         [{t,t,1,[{file,"t.erl"},{line,5}]},
          ...]}}

With Shippai

$ erlc +'{core_transform,shippai_transform}' t.erl
$ erl
1> t:t(foo).
** exception error: no case clause matching foo
     in function  t:t/1
        called as t:t(foo)
1> catch t:t(foo).
{'EXIT',{{case_clause,foo},
         [{t,t,[foo],[{file,"t.erl"},{line,5}]},
          ...]}}

What is there to do?

• Write better documentation.
• Write tests.
• Create convenience functions to (de-)instrument a given module.
• Patch OTP to print both line numbers and function arguments in the REPL.

License

Shippai is published under the ISC license.

From Wikipedia:

The ISC license is a permissive free software license written by the Internet Systems Consortium (ISC). It is functionally equivalent to the Simplified BSD License, with language that was made unnecessary by the Berne convention removed.