I found this answer on http://www.oipapio.com/question-79176

documentclass[10pt,a5paper,twoside]{article}

usepackage{hyphenat}



cs_new:Npn hyphenfix_emdash:c {---}

cs_new:Npn hyphenfix_endash:c {--}



cs_new:Npn hyphenfix_discardnext:NN #1#2{#1}





catcode`-=active



cs_new_protected:Npn -{

    futurelethyphenfix_nexttokhyphenfix_i:w

}



cs_new:Npn hyphenfix_i:w {

    cs_if_eq:NNTF{hyphenfix_nexttok}{-}{

        %discard the next `-` token

        hyphenfix_discardnext:NN{futurelethyphenfix_nexttokhyphenfix_ii:w}

    }{

        % from package hyphenat

        hyp

    }

}



cs_new:Npn hyphenfix_ii:w {

    cs_if_eq:NNTF{hyphenfix_nexttok}{-}{

        hyphenfix_discardnext:NN{hyphenfix_emdash:c}

    }{

        hyphenfix_endash:c

    }

}



begin{document}



section{Show font}



    Tests.



    Encoding-encoding-encoding-encoding-encoding-encoding-encoding-encoding-encoding-encoding.



    Encodinghyp{}encodinghyp{}encodinghyp{}encodinghyp{}encodinghyp{}encodinghyp{}encodinghyp{}encodinghyp{}encodinghyp{}encoding.



end{document}

It should allow me to use - as hyp{} and two -- as one -, but when compiling it throws this error:

Package: hyphenat 2009/09/02 v2.3c hyphenation utilities

langwohyphens=language77

LaTeX Info: Redefining _ on input line 43.

)test1.tex:4: Undefined control sequence

Here is how much of TeX's memory you used:

 232 strings out of 493314

This feature would be very welcomed because, in my language, I use a lot of - (hyphens) and it is horrible to keep typing (and remembering to type) hyp{} everywhere.

Related questions:

1. Adequate hyphenation of words already containing a hyphen


2. Hyphenat not hyphenating words with hyphens


3. How to copy minus as hyphen?


4. Problem expanding acronyms containing hyp{} in captions


5. Hyphenation problem

Update

I managed to get it working after adding the expl3 package. I thought it was not required. Full example:

documentclass[10pt,a5paper,twoside]{article}

usepackage{hyphenat}

usepackage{expl3}



ExplSyntaxOn

cs_new:Npn hyphenfix_emdash:c {---}

cs_new:Npn hyphenfix_endash:c {--}



cs_new:Npn hyphenfix_discardnext:NN #1#2{#1}





catcode`-=active



cs_new_protected:Npn -{

    futurelethyphenfix_nexttokhyphenfix_i:w

}



cs_new:Npn hyphenfix_i:w {

    cs_if_eq:NNTF{hyphenfix_nexttok}{-}{

        %discard the next `-` token

        hyphenfix_discardnext:NN{futurelethyphenfix_nexttokhyphenfix_ii:w}

    }{

        % from package hyphenat

        hyp

    }

}



cs_new:Npn hyphenfix_ii:w {

    cs_if_eq:NNTF{hyphenfix_nexttok}{-}{

        hyphenfix_discardnext:NN{hyphenfix_emdash:c}

    }{

        hyphenfix_endash:c

    }

}

ExplSyntaxOff



begin{document}



section{Show font}



    Tests.



    Encoding-encoding-encoding-encoding-encoding-encoding-encoding-encoding-encoding-encoding.



    Encodinghyp{}encodinghyp{}encodinghyp{}encodinghyp{}encodinghyp{}encodinghyp{}encodinghyp{}encodinghyp{}encodinghyp{}encoding.



end{document}

Now, by curiosity. Why I do not see much people using this trick everywhere else?

Does this command is breaking something in latex? Then, is it unadvised to use it?