Add xleb, charter, and dmesktop entries
Rosencrantz
5 years ago
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_model: page
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---
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title: xleb
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---
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body:
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The [xleb](https://github.com/aisamanra/xleb) library is a DSL for declaratively parsing XML structures. It uses a monadic structure to implicitly traverse the underlying XML structure, match on parts, and extract the relevant data.
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Consider an XML format that looks like the following, with the `author` tags being considered optional:
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```haskell
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<feed>
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<title>Feed Name</title>
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<author>Pierre Menard</author>
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<entry title="Entry 01">First Post</entry>
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<entry title="Entry 02">Second Post Post</entry>
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</feed>
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```
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A parser for this format using the `xleb` library might look like this:
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```haskell
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import Control.Applicative (optional)
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import qualified Text.XML.Xleb as X
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data Feed = Feed
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{ feedTitle :: String
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, feedAuthor :: Maybe String
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, feedEntry :: [Entry]
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} deriving (Eq, Show)
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data Entry = Entry
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{ entryTitle :: String
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, entryContents :: String
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} deriving (Eq, Show)
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feed :: X.Xleb Feed
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feed = X.elem "feed" $ do
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feedTitle <- X.child (X.byTag "title") $ X.contents X.string
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feedAuthor <- optional $ X.child (X.byTag "author") $ X.contents X.string
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feedEntries <- X.children (X.byTag "entry") entry
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return Feed { .. }
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entry :: X.Xleb Entry
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entry = Entry <$> X.attr "title" X.string <*> X.contents X.string
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```
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_model: page
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---
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title: Charter
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---
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body:
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The [charter](https://github.com/aisamanra/charter) tool is a basic tool for Cabal-based project scaffolding. There are a number of tools that do this—Cabal comes with the `cabal init` command built-in, for example, and there's also the heavily configurable [`hi`](https://github.com/fujimura/hi) project—but none of them had quite what I wanted, so I built my own.
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It has three main modes of operation, all of which will create a directory that contains a `cabal` file, initialize a git repo, and build out whatever other scaffolding is required. For basic executables, you can use
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```
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$ charter quick the-thing
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```
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and it will create `the-thing/the-thing.cabal` and `the-thing/src/Main.hs` for you, with a trivial entry point, and initialize a git repo with them. For a library, you can use a similar command, with optional `-m` flags to add new modules
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```
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$ charter library the-thing -m This -m That.TheOther
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```
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and in addition to `the-thing/the-thing.cabal`, it will also create the stubbed-out library modules `the-thing/src/This.hs` and `the-thing/src/That/TheOther.hs`. Finally, for larger executables (which I prefer to implement as a wrapper executable along with a library), you can use
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```
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$ charter executable the-thing
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```
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and in addition to `the-thing/the-thing.cabal`, it will also create the stubbed-out library code in `the-thing/src/TheThing.hs` as well as stubbed-out executable code in `the-thing/the-thing/Main.hs`.
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All of these commands can also take other flags that fill in Cabal metadata: for example, `-l GPL` to specify a GPL license, `-d "some description"` to set the package description, `-a package-name` to add a dependency, and so forth. You can also add extra executable stanzas with `-b executable-name` and modules with `-m ModuleName`.
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_model: page
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---
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title: dmesktop
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---
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body:
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The [`dmesktop` program](https://github.com/aisamanra/dmesktop) is an application launcher for Linux based on `dmenu`, but using [XDG Desktop entries](https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html) instead of exposing every binary in your `$PATH`. It is unfinished but usable, and can be installed with the following `cargo` command:
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```
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$ cargo install --git https://github.com/aisamanra/dmesktop.git
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```
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One mild frustration I had with the built-in `dmenu_run` launcher application is that it will allow you to uselessly launch non-graphical programs in a context where they will never be useful: running `sed` without arguments from a graphical context, for example. In contrast, `dmesktop` will only display applications which would also be offered by a desktop manager such as GNOME.
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In my own usage, I have `dmenu_run` still bound and use it occasionally, but usually use `dmesktop` as my primary application launcher.
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<nav class="menu">
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<ul class="nav navbar-nav">
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<li><a href="/">home</a></li>
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<li>projects</li>
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<li>tools and programs</li>
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<ul>
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<li><a href="/projects/bricoleur">bricoleur</a></li>
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<li><a href="/projects/charter">charter</a></li>
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<li><a href="/projects/dmesktop">dmesktop</a></li>
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<li><a href="/projects/matterhorn">matterhorn</a></li>
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</ul>
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<li>libraries</li>
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<li><a href="/libraries/config-ini">config-ini</a></li>
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<li><a href="/libraries/cube-cotillion">cube cotillion</a></li>
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| 25 | 27 |
<li><a href="/libraries/telml">telml</a></li>
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<li><a href="/libraries/xleb">xleb</a></li>
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</ul>
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<li>art & writing</li>
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<ul>
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