lucid: Clear to write, read and edit DSL for HTML

[ bsd3, library, web ] [ Propose Tags ]
Versions 0.0, 0.1, 0.2, 0.3, 0.4, 1.0, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6.0, 2.6.1, 2.7.0, 2.8.0, 2.8.1, 2.9.0, 2.9.1, 2.9.2, 2.9.3, 2.9.4, 2.9.5, 2.9.6, 2.9.7, 2.9.8,, 2.9.9, 2.9.10
Change log
Dependencies base (>=4.8 && <5), blaze‑builder, bytestring, containers, hashable, mmorph, mtl, semigroups, text, transformers, unordered‑containers [details]
License BSD-3-Clause
Copyright 2014-2017 Chris Done
Author Chris Done
Category Web
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Uploaded by phadej at Thu Mar 15 14:24:55 UTC 2018
Distributions Debian:2.9.4, LTSHaskell:2.9.10, NixOS:2.9.10, Stackage:2.9.10, openSUSE:2.9.9
Downloads 12655 total (208 in the last 30 days)
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Status Docs available [build log]
Last success reported on 2018-03-15 [all 1 reports]
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Clear to write, read and edit DSL for HTML.

See the Lucid module for more documentation.

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Readme for lucid-2.9.10

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lucid Hackage Build Status

Clear to write, read and edit DSL for writing HTML


lucid-from-html will convert html to the lucid DSL, though it is experimental.


HTML terms in Lucid are written with a postfix ‘_’ to indicate data rather than code. Some examples:

p_, class_, table_, style_

See Lucid.Html5 for a complete list of Html5 combinators.

Plain text is written using the OverloadedStrings and ExtendedDefaultRules extensions, and is automatically escaped:

λ> "123 < 456" :: Html ()
123 &lt; 456

Elements nest by function application:

λ> table_ (tr_ (td_ (p_ "Hello, World!"))) :: Html ()
<table><tr><td><p>Hello, World!</p></td></tr></table>

Elements are juxtaposed via monoidal append:

λ> p_ "hello" <> p_ "sup" :: Html ()

Or monadic sequencing:

λ> div_ (do p_ "hello"; p_ "sup") :: Html ()

Attributes are set by providing an argument list:

λ> p_ [class_ "brand"] "Lucid Inc" :: Html ()
<p class="brand">Lucid Inc</p>

Here is a fuller example of Lucid:

table_ [rows_ "2"]
       (tr_ (do td_ [class_ "top",colspan_ "2",style_ "color:red"]
                    (p_ "Hello, attributes!")
                td_ "yay!"))
<table rows="2">
    <td style="color:red" colspan="2" class="top">
      <p>Hello, attributes!</p>


For proper rendering you can easily run some HTML immediately with:

λ> renderText (p_ "Hello!")

Or to bytes:

λ> renderBS (p_ [style_ "color:red"] "Hello!")
"<p style=\"color:red\">Hello!</p>"

For ease of use in GHCi, there is a Show instance, as demonstrated above.

If the above rendering functions aren't suited for your purpose, you can run the monad directly via execHtml and use the more low-level blaze Builder, which has a plethora of output modes in Blaze.ByteString.Builder.

See the documentation for the Lucid module for information about using it as a monad transformer.


You can use lift to call parent monads.

λ> runReader (renderTextT (html_ (body_ (do name <- lift ask
                                            p_ [class_ "name"] (toHtml name)))))
             ("Chris" :: String)
"<html><body><p class=\"name\">Chris</p></body></html>"