interpolation - Unknown haskell operator; `<>` -

-

this code appears use <> interpolation operator. https://github.com/hlian/linklater/blob/master/examples/app/jointphotographicexpertsgrouptonga.hs

i can not find documentation nor source operator. ideas does/where from.

traditionally, <> function defined in data.monoid.

(<>) :: monoid => -> -> (<>) = mappend

however, semigroups package has long used method of semigroup class in data.semigroup. of ghc 8, data.semigroup has moved base package. there plan in place making semigroup superclass of monoid. once complete, <> function entirely replaced <> method.


Comments

Post a Comment

Popular posts from this blog

sql - invalid in the select list because it is not contained in either an aggregate function -

-
i can't figure out rewrite sql statement avoid error below msg 8120, level 16, state 1, line 26 column 'staffmember.staffmemberid' invalid in select list because not contained in either aggregate function or group clause. sql statment select (select [dbo].[udf_readstaffmemberbasic](sm.staffmemberid) xml path ('staffmembersummary'), root ('items'), type ), count(sm.staffmemberid) totalresults, ceiling(cast(count(sm.staffmemberid) decimal)/ @pagesize) totalpages staffmember sm inner join staffmembertoadditionalrole ar on sm.staffmemberid = ar.staffmemberid (sm.firstname '%' + @name + '%' or sm.surname '%' + @name + '%') , (@floorid null or sm.floorid = @floorid) , (@directorateid null or sm.directorateid = @directorateid) , (@additionalroleid null or ar.additionalroleid = @additionalroleid) order sm.staffmemberid offset @page * @pagesize rows fe...
Read more

Angularjs unit testing - ng-disabled not working when adding text to textarea -

-
i trying test angularjs component using karma, mocha, power-assert. have textarea , button in component, button disabled based on length of text in textarea. when run component in browser works perfectly. can't figure out how test functionality. here's bit of code. inquiryform.js function inquiryform($scope) { // plan add logic here } angular.module('myapp').component('inquiryform', { controller: inquiryform, controlleras: 'inquiryform', templateurl: 'inquiryform.html' }); inquiryform.html <div class="contact"> <div>thanks contacting us.</div> <form> <textarea ng-model="inquiryform.inquirytext" name=""></textarea> <input type="submit" value="send" ng-disabled="!inquiryform.inquirytext.length"> </form> </div> inquiryformtest.js describe('inquiry form ', () => { let $r...
Read more

python - Error opening file in H5PY (File signature not found) -

-
i've been using following bit of code open hdf5 files, produced in matlab, in python using h5py: import h5py h5 data='dataset.mat' f=h5.file(data, 'r') however i'm getting following error: oserror: unable open file (file signature not found) i've checked files i'm trying open version 7.3 mat-files , hdf5 format. in fact i've used h5py open same files before. i've confirmed files exist , accessible i'm not sure error coming from. advice appreciated, in advance : ) usually message file signature not found indicates either: 1. file corrupted. ... think likely. said you've opened files before. maybe forgot closing file-handle can corrupt file. try checking file hdf5 utility h5debug (available on command line if you've installed hdf5 lib on os, check dpkg -s libhdf5-dev on linux). 2. file not in hdf5 format. this known cause error message. since said made sure, case , you've opened files before, i...
Read more