-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Map the arguments and return value of functions.
--   
--   Map the arguments and return value of functions.
@package data-function-meld
@version 0.1.1.0


-- | Map the arguments and return value of functions.
--   
--   General use:
--   
--   <ul>
--   <li><pre>f $* g1 $$ g2 … $$ gn *$ h = \x1 … xn -&gt; h (f (g1 x1) (g2
--   x2) … (gn xn))</pre></li>
--   </ul>
--   
--   Examples:
--   
--   <ul>
--   <li><pre>on f g = f $* g $$ g *$ id</pre></li>
--   <li><pre>comparing f = compare $* f $$ f *$ id</pre></li>
--   <li><pre>f . g = f $* g *$ id</pre></li>
--   </ul>
--   
--   Related work:
--   
--   <ul>
--   <li><a>Semantic Editor Combinators</a> (Conal Elliott, 2008/11/24).
--   Introduces composable editors for function arguments and return
--   values.</li>
--   <li><a>Pointless Fun</a> (Matt Hellige, 2008/12/03). Derives a similar
--   operator named <tt>~&gt;</tt>. This operator composes an editor which
--   can then be applied to the subject to edit. This better agrees with
--   Conal's concept of Semantic Editor Combinators. In contrast,
--   <tt>$*</tt> includes the subject as part of the editor, though you can
--   write <tt>($* g1 $$ g2 … $$ gn *$ h)</tt> for an editor independent of
--   the subject. Also, <tt>~&gt;</tt> is right-associative whereas
--   <tt>$*</tt> and <tt>$$</tt> are left-associative.</li>
--   <li><a>TypeCompose version 0.9.11</a> (Conal Elliott, 2016/01/15).
--   Package including an implementation of <tt>~&gt;</tt>.</li>
--   </ul>
module Data.Function.Meld

-- | Begin melding.
--   
--   <pre>
--   f $* g1 $$ g2 … $$ gn *$ h = \x1 … xn -&gt; h (f (g1 x1) (g2 x2) … (gn xn))
--   </pre>
($*) :: Category cat => cat b c -> cat a b -> cat c d -> cat a d

-- | Continue melding.
--   
--   <pre>
--   f $* g1 $$ g2 … $$ gn *$ h = \x1 … xn -&gt; h (f (g1 x1) (g2 x2) … (gn xn))
--   </pre>
($$) :: Category cat => ((cat b c -> cat a d) -> e) -> cat a b -> cat c d -> e

-- | Finish melding.
--   
--   <pre>
--   f $* g1 $$ g2 … $$ gn *$ h = \x1 … xn -&gt; h (f (g1 x1) (g2 x2) … (gn xn))
--   </pre>
(*$) :: Category cat => cat a b -> cat a b