Gists for the FeatureLearn Erlang course (1.9)

first.erl

-module(first).

-export([
    double/1,
    mult/2,
    area/3,
    square/1,
    trbl/1,
    sum/3
]).


mult(X,Y) ->
    X*Y.

double(X) ->
    mult(2,X).

area(A,B,C) ->
    S = sum(A,B,C)/2,
    math:sqrt(S*(S-A)*(S-B)*(S-C)).

square(X) ->
    mult(X,X).

trbl(X) ->
    mult(3,X).

sum(X,Y,Z) ->
    X+Y+Z.

second.erl

-module(second).

-import(first,[
    square/1,
    area/3,
    sum/3
]).

-export([
    hypotenuse/2,
    area/2,
    perimeter/2
]).

% given two sides of a tractangle triangle returns the size of the hypotenuse
hypotenuse(X,Y) ->
    math:sqrt(square(X) + square(Y)).

% given two sides of a triangle rectangle returns the area
area(X,Y) ->
    H = hypotenuse(X,Y),
    area(X,Y,H).

% given two sides of a tractangle triangle returns the perimeter
perimeter(X,Y) ->
    H = hypotenuse(X,Y),
    sum(X,Y,H).

It's a generic practice. Check it out: http://erlang.org/doc/apps/edoc/chapter.html
About importing functions with similar names… I believe that the compiler will tell you that the function is redefined (you should try and see…). But I wrote a long comment on FutureLearn stating why I think it's not wise to use -import. Basically, it makes code harder to understand and debug. Not super noticeable in small modules, but definitely hideous in large ones.

Ah, sí… podemos hablar en porteño si te cabe, eh? Por mí, todo bien :P

Aaaajáa. A la tarde voy a estar chequeando los mensajes de esa fase sección cuando remote los ejercicios. Esta bastante entretenido! 🎉