<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html> <head> <!-- Generated by HsColour, http://www.cs.york.ac.uk/fp/darcs/hscolour/ --> <title>Data/Functor/Product.hs</title> <link type='text/css' rel='stylesheet' href='hscolour.css' /> </head> <body> <pre><a name="line-1"></a><span class='hs-comment'>-- |</span> <a name="line-2"></a><span class='hs-comment'>-- Module : Data.Functor.Product</span> <a name="line-3"></a><span class='hs-comment'>-- Copyright : (c) Ross Paterson 2010</span> <a name="line-4"></a><span class='hs-comment'>-- License : BSD-style (see the file LICENSE)</span> <a name="line-5"></a><span class='hs-comment'>--</span> <a name="line-6"></a><span class='hs-comment'>-- Maintainer : ross@soi.city.ac.uk</span> <a name="line-7"></a><span class='hs-comment'>-- Stability : experimental</span> <a name="line-8"></a><span class='hs-comment'>-- Portability : portable</span> <a name="line-9"></a><span class='hs-comment'>--</span> <a name="line-10"></a><span class='hs-comment'>-- Products, lifted to functors.</span> <a name="line-11"></a> <a name="line-12"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Functor</span><span class='hs-varop'>.</span><span class='hs-conid'>Product</span> <span class='hs-layout'>(</span> <a name="line-13"></a> <span class='hs-conid'>Product</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span> <a name="line-14"></a> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span> <a name="line-15"></a> <a name="line-16"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Applicative</span> <a name="line-17"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Foldable</span> <span class='hs-layout'>(</span><span class='hs-conid'>Foldable</span><span class='hs-layout'>(</span><span class='hs-varid'>foldMap</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <a name="line-18"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Monoid</span> <span class='hs-layout'>(</span><span class='hs-varid'>mappend</span><span class='hs-layout'>)</span> <a name="line-19"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Traversable</span> <span class='hs-layout'>(</span><span class='hs-conid'>Traversable</span><span class='hs-layout'>(</span><span class='hs-varid'>traverse</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span> <a name="line-20"></a> <a name="line-21"></a><a name="Product"></a><span class='hs-comment'>-- | Lifted product of functors.</span> <a name="line-22"></a><a name="Product"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>Product</span> <span class='hs-varid'>f</span> <span class='hs-varid'>g</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Pair</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>g</span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <a name="line-23"></a> <a name="line-24"></a><span class='hs-keyword'>instance</span> <span class='hs-layout'>(</span><span class='hs-conid'>Functor</span> <span class='hs-varid'>f</span><span class='hs-layout'>,</span> <span class='hs-conid'>Functor</span> <span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Functor</span> <span class='hs-layout'>(</span><span class='hs-conid'>Product</span> <span class='hs-varid'>f</span> <span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span> <a name="line-25"></a> <span class='hs-varid'>fmap</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Pair</span> <span class='hs-varid'>x</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Pair</span> <span class='hs-layout'>(</span><span class='hs-varid'>fmap</span> <span class='hs-varid'>f</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>fmap</span> <span class='hs-varid'>f</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span> <a name="line-26"></a> <a name="line-27"></a><span class='hs-keyword'>instance</span> <span class='hs-layout'>(</span><span class='hs-conid'>Foldable</span> <span class='hs-varid'>f</span><span class='hs-layout'>,</span> <span class='hs-conid'>Foldable</span> <span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Foldable</span> <span class='hs-layout'>(</span><span class='hs-conid'>Product</span> <span class='hs-varid'>f</span> <span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span> <a name="line-28"></a> <span class='hs-varid'>foldMap</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Pair</span> <span class='hs-varid'>x</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>foldMap</span> <span class='hs-varid'>f</span> <span class='hs-varid'>x</span> <span class='hs-varop'>`mappend`</span> <span class='hs-varid'>foldMap</span> <span class='hs-varid'>f</span> <span class='hs-varid'>y</span> <a name="line-29"></a> <a name="line-30"></a><span class='hs-keyword'>instance</span> <span class='hs-layout'>(</span><span class='hs-conid'>Traversable</span> <span class='hs-varid'>f</span><span class='hs-layout'>,</span> <span class='hs-conid'>Traversable</span> <span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Traversable</span> <span class='hs-layout'>(</span><span class='hs-conid'>Product</span> <span class='hs-varid'>f</span> <span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span> <a name="line-31"></a> <span class='hs-varid'>traverse</span> <span class='hs-varid'>f</span> <span class='hs-layout'>(</span><span class='hs-conid'>Pair</span> <span class='hs-varid'>x</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Pair</span> <span class='hs-varop'><$></span> <span class='hs-varid'>traverse</span> <span class='hs-varid'>f</span> <span class='hs-varid'>x</span> <span class='hs-varop'><*></span> <span class='hs-varid'>traverse</span> <span class='hs-varid'>f</span> <span class='hs-varid'>y</span> <a name="line-32"></a> <a name="line-33"></a><span class='hs-keyword'>instance</span> <span class='hs-layout'>(</span><span class='hs-conid'>Applicative</span> <span class='hs-varid'>f</span><span class='hs-layout'>,</span> <span class='hs-conid'>Applicative</span> <span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Applicative</span> <span class='hs-layout'>(</span><span class='hs-conid'>Product</span> <span class='hs-varid'>f</span> <span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span> <a name="line-34"></a> <span class='hs-varid'>pure</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Pair</span> <span class='hs-layout'>(</span><span class='hs-varid'>pure</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>pure</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <a name="line-35"></a> <span class='hs-conid'>Pair</span> <span class='hs-varid'>f</span> <span class='hs-varid'>g</span> <span class='hs-varop'><*></span> <span class='hs-conid'>Pair</span> <span class='hs-varid'>x</span> <span class='hs-varid'>y</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Pair</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varop'><*></span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>g</span> <span class='hs-varop'><*></span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span> <a name="line-36"></a> <a name="line-37"></a><span class='hs-keyword'>instance</span> <span class='hs-layout'>(</span><span class='hs-conid'>Alternative</span> <span class='hs-varid'>f</span><span class='hs-layout'>,</span> <span class='hs-conid'>Alternative</span> <span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=></span> <span class='hs-conid'>Alternative</span> <span class='hs-layout'>(</span><span class='hs-conid'>Product</span> <span class='hs-varid'>f</span> <span class='hs-varid'>g</span><span class='hs-layout'>)</span> <span class='hs-keyword'>where</span> <a name="line-38"></a> <span class='hs-varid'>empty</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Pair</span> <span class='hs-varid'>empty</span> <span class='hs-varid'>empty</span> <a name="line-39"></a> <span class='hs-conid'>Pair</span> <span class='hs-varid'>x1</span> <span class='hs-varid'>y1</span> <span class='hs-varop'><|></span> <span class='hs-conid'>Pair</span> <span class='hs-varid'>x2</span> <span class='hs-varid'>y2</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Pair</span> <span class='hs-layout'>(</span><span class='hs-varid'>x1</span> <span class='hs-varop'><|></span> <span class='hs-varid'>x2</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>y1</span> <span class='hs-varop'><|></span> <span class='hs-varid'>y2</span><span class='hs-layout'>)</span> </pre></body> </html>
