You may ask...what is Mercury?
Mercury looks like Prolog, but feels like strict Haskell or pure OCaml.In other words is a logical, functional and object-oriented programming language...
As always...I needed to develop an app to learn how to use it...and while it gave me more than one headache...here it is -;)
fibo.m |
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:- module fibo. :- interface. :- import_module io. :- pred main(io::di, io::uo) is det. :- implementation. :- import_module string, int. :- pred fibo(int::in, int::in, int::in, string::out) is det. fibo(NUM, A, B, FIBS) :- ( if A = 0 then fibo(NUM-1,A+B,B,FIB), FIBS = int_to_string(A) ++ " " ++ int_to_string(B) ++ " " ++ int_to_string(A+B) ++ " " ++ FIB else if A > 0, NUM > 1 then fibo(NUM-1,A+B,A,FIB), FIBS = int_to_string(A+B) ++ " " ++ FIB else FIBS = "" ). main(!IO) :- io.write_string("Enter a number: ",!IO), io.read_line_as_string(Result, !IO), ( if Result = ok(String), string.to_int(string.strip(String), N) then fibo(N,0,1,FIBS), io.write_string(FIBS,!IO) else io.write_string("Not a number...",!IO) ). |
The cool thing about Mercury is that it forces you to not allow your app to fail...as the "else" is mandatory...if you enter a number then it's fine...but if you enter a letter, you are forced to do something...
Here are the pics...
Greetings,
Blag.
Development Culture.
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