diff options
Diffstat (limited to 'content/posts/2018/2018-03-20-perl6-introduction-to-application-programming.md')
| -rw-r--r-- | content/posts/2018/2018-03-20-perl6-introduction-to-application-programming.md | 58 |
1 files changed, 29 insertions, 29 deletions
diff --git a/content/posts/2018/2018-03-20-perl6-introduction-to-application-programming.md b/content/posts/2018/2018-03-20-perl6-introduction-to-application-programming.md index 21c4298..c1d2df7 100644 --- a/content/posts/2018/2018-03-20-perl6-introduction-to-application-programming.md +++ b/content/posts/2018/2018-03-20-perl6-introduction-to-application-programming.md @@ -13,10 +13,10 @@ tags: # Perl 6 - Introduction to application programming In this tutorial, I'll be guiding you through creating a simple application in -Perl 6. If you don't have Perl 6 installed yet, get the -[http://rakudo.org/how-to-get-rakudo/](Rakudo Star) distribution for your OS. -Alternatively, you can use the [https://hub.docker.com/_/rakudo-star/](Docker -image). +Perl 6. If you don't have Perl 6 installed yet, get the [Rakudo +Star](http://rakudo.org/how-to-get-rakudo/) distribution for your OS. +Alternatively, you can use the [Docker +image](https://hub.docker.com/_/rakudo-star/). The application itself will be a simple dice-roller. You give it a number of dice to roll, and the number of sides the die has. We'll start off by creating @@ -69,9 +69,9 @@ This is the name given to the module. This will be used for the directory name, which by default in `assixt` will be `perl6-` prepended to a lower-case version of the module name. If you ever wish to make a module that is to be shared in the Perl 6 ecosystem, this should be unique across the entire ecosystem. If -you're interested in some guidelines, the -[https://pause.perl.org/pause/query?ACTION=pause_namingmodules](PAUSE -guidelines) seem to apply pretty well to Perl 6 as well. +you're interested in some guidelines, the [PAUSE +guidelines](https://pause.perl.org/pause/query?ACTION=pause_namingmodules) seem +to apply pretty well to Perl 6 as well. For this application, we'll use `Local::App::Dicer`, but you can use whatever name you'd prefer here. @@ -106,7 +106,7 @@ This indicates the license under which your module is distributed. This defaults to `GPL-3.0`, which I strongly recommend to use. The de-facto default seems to be `Artistic-2.0`, which is also used for Perl 6 itself. -This identifier is based on the [https://spdx.org/licenses/](SPDX license list). +This identifier is based on the [SPDZ license list](https://spdx.org/licenses/). Anything not mentioned in this list is not acceptable. #TODO Clarify why ## Writing your first test @@ -170,28 +170,28 @@ subtest "Illegal rolls", { {{< admonition title="note" >}} Perl 6 allows mathematical characters to make your code more concise, as with -the ≤ in the above block. If you use http://www.vim.org/[vim], you can make use -of the https://github.com/vim-perl/vim-perl6[vim-perl6] plugin, which has an +the ≤ in the above block. If you use [vim](http://www.vim.org/), you can make use +of the [vim-perl6](https://github.com/vim-perl/vim-perl6) plugin, which has an option to change the longer, ascii-based ops (in this case `\<=`) into the shorter unicode based ops (in this case `≤`). This specific feature requires `let g:perl6_unicode_abbrevs = 1` in your `vimrc` to be enabled with `vim-perl6`. If that's not an option, you can use a -https://en.wikipedia.org/wiki/Compose_key[compose key]. If that is not viable +[compose key](https://en.wikipedia.org/wiki/Compose_key). If that is not viable either, you can also stick to using the ascii-based ops. Perl 6 supports both of them. {{< / admonition >}} This will run 53 tests, split up in two -[https://docs.perl6.org/language/testing#Grouping_tests](subtests). Subtests are -used to logically group your tests. In this case, the calls that are correct -are in one subtest, the calls that should be rejected are in another. +[subtests](https://docs.perl6.org/language/testing#Grouping_tests). Subtests are +used to logically group your tests. In this case, the calls that are correct are +in one subtest, the calls that should be rejected are in another. The `plan` keywords indicate how many tests should be run. This will help spot errors in case your expectations were not matched. For more information on -testing, check out [https://docs.perl6.org/language/testing](the Perl 6 docs on -testing). +testing, check out [the Perl 6 docs on +testing](https://docs.perl6.org/language/testing). We're making use of two test routines, `ok` and `throws-like`. `ok` is a simple test: if the given statement is truthy, the test succeeds. The other @@ -243,7 +243,7 @@ use v6.c; unit module Local::App::Dicer; ``` -The first line is a [https://en.wikipedia.org/wiki/Shebang_(Unix)](shebang). It +The first line is a [shebang](https://en.wikipedia.org/wiki/Shebang_(Unix)). It informs the shell what to do when you try to run the file as an executable program. In this case, it will run `false`, which immediately exits with a non-success code. This file needs to be run as a Perl 6 module file, and @@ -424,10 +424,10 @@ $ perl6 -Ilib bin/dicer 2 20 ### The usage output Now, we still have the trouble of illegal number input not clearly telling -what's wrong. We can do a neat trick with -[https://docs.perl6.org/language/functions#index-entry-USAGE](the USAGE sub) to -achieve this. Perl 6 allows a subroutine with the name `USAGE` to be defined, -overriding the default behaviour. +what's wrong. We can do a neat trick with [the `USAGE` +sub](https://docs.perl6.org/language/functions#index-entry-USAGE) to achieve +this. Perl 6 allows a subroutine with the name `USAGE` to be defined, overriding +the default behaviour. Using this, we can generate a friendlier message informing the user what they need to supply more clearly. The `USAGE` sub would look like this: @@ -448,8 +448,8 @@ You now have a working console application in Perl 6! ## a simple GUI But that's not all. Perl 6 has a module to create GUIs with the -[https://www.gtk.org/](GTK library) as well. For this, we'll use the -[https://github.com/perl6/gtk-simple](`GTK::Simple`) module. +[GTK library](https://www.gtk.org/) as well. For this, we'll use the +[`GTK::Simple`](https://github.com/perl6/gtk-simple) module. You can add this module as a dependency to the `Local::App::Dicer` repository with `assixt` as well, using the `depend` command. By default, this will also @@ -463,11 +463,11 @@ $ assixt depend GTK::Simple Next, we could create another executable file and call it `dicer-gtk`. However, I can also use this moment to introduce -[https://docs.perl6.org/language/glossary#index-entry-multi-method](multi -methods). These are subs with the same name, but differing signatures. If a -call to such a sub could potentially match multiple signatures, the most -specific one will be used. We will add another `MAIN` sub, which will be called -when `bin/dicer` is called with the `--gtk` parameter. +[multi-methods](https://docs.perl6.org/language/glossary#index-entry-multi-method). +These are subs with the same name, but differing signatures. If a call to such a +sub could potentially match multiple signatures, the most specific one will be +used. We will add another `MAIN` sub, which will be called when `bin/dicer` is +called with the `--gtk` parameter. We should also update the `USAGE` sub accordingly, of course. And while we're at it, let's also include the `GTK::Simple` and `GTK::Simple::App` modules. The @@ -526,7 +526,7 @@ in Perl 6. Any method can be given a non-positional, named parameter. This is done by appending a `:` in front of the variable name in the sub signature. This has already been used in our code, in `multi sub MAIN(Bool :$gtk where $gtk == True)`. This has a couple of benefits, which are explained in the -[https://docs.perl6.org/type/Signature#index-entry-positional_argument_%28Signature%29_named_argument_%28Signature%29](Perl 6 docs on signatures). +[Perl 6 docs on signatures](https://docs.perl6.org/type/Signature#index-entry-positional_argument_%28Signature%29_named_argument_%28Signature%29). ### Creating the elements |