list - Haskell split tuple array where first elements are the same -

-

i have list in haskell of form similar to

[([], "str1"), ([], "str2"), ([1], "ser1")]

and want split separate lists of 2-tuples, first elements of each tuple same, so

[([], "str1"), ([], "str2")] [([1], "ser1")]

i''ve been eyeing data.list.split's splitwhen function, i've been having trouble getting ghc accept predicate it, since gather wasn't meant that.

i think can use groupby:

> import data.list > import data.function  > let xs = [([], "str1"), ([], "str2"), ([1], "ser1")]  > groupby ((==) `on` fst) xs  [[([],"str1"),([],"str2")], [([1],"ser1")]]

Comments

Post a Comment

Popular posts from this blog

google chrome - Developer tools - How to inspect the elements which are added momentarily (by JQuery)? -

-
i looking @ how website designed using inspector in chrome. can use firefox developer tools or firefox web developer add-on or chrome web developer extension. so website has slide-show , using jquery it. looking @ markup , css in inspector, i see 2 things constantly changing slides change: one opacity css property understandable, i'd see changing values, changes fast see read anything. second- a div added in div slides change momentarily , moment when appears short notice except div . so question is there way stop slideshow can temporarily rid of blinking sort of effect (by speedy adding , removal , changing of elements , values)? where can inspect div element gets added such short moment , , gets removed? , can see changes in value of opacity takes place? is there way stop slideshow can temporarily rid of blinking sort of effect (by speedy adding , removal , changing of elements , values)? if opacity animated css transition or animation,
Read more

angularjs - Showing an empty as first option in select tag -

-
my app showing empty select field first entry. have read other solution given , tried still not working. my controller code is: .controller('usercreatecontroller', function(user,profile,auth) { alert("hello"); var vm = this; vm.type = 'create'; profile.all() //this service fetch profiles shown in select field .success(function(data){ vm.profile = data; }); vm.userdata.profile = vm.profile[0]; //here have set default value select field and html page is: <label class="col-sm-2 control-label">profile</label> <div class="col-sm-8"> <select ng-model="user.userdata.profile" ng-options="person._id person.profilename person in user.profile"> </select> </div> hierarchy of vm.profile { "_id": 46, "profile": objectid("5516498e95b84548156db754"), "isactive": true, "password": "$2
Read more

php - Cloud9 cloud IDE and CakePHP -

-
i attempting cakephp running on cloud9, cloud based ide. unaware, cloud collaboration ide intermixes services such bitbucket. site gives sudo rights, , installed cakephp using these instructions: https://www.digitalocean.com/community/tutorials/how-to-install-cakephp-on-an-ubuntu-12-04-vps when attempt run database exported machine cakephp installed, error message "url rewriting not configured on server." attempted solve issue using official guide cakephp: http://book.cakephp.org/2.0/en/installation/url-rewriting.html but no cigar, same error message. has gotten cakephp working, or aware of cloud ide free/low cost cloud9 support cakephp? here's how got working now: sudo apt-get update sudo apt-get install php5-intl curl -ss https://getcomposer.org/installer | php -- --filename=composer ./composer create-project --prefer-dist cakephp/app this creates project in /app default. move workspace docroot: mv app/* ./ mv app/.* ./ rm -rf app then de
Read more