haskell - Minimum of Two Maybes -

-

i want minimum of 2 maybe values, or if 1 nothing non-nothing one, or return nothing if both inputs nothing. can write simple function this, suspect there way without writing custom function. sorry, if petty question, there simpler way using custom function?

minmaybe :: ord => maybe -> maybe -> maybe minmaybe nothing b = b minmaybe nothing = minmaybe (just a) (just b) = $ min b

you cannot use applicative, or monad instance this, since nothing in contexts have total result being nothing. being said, term "simpler" highly opinionated, , function fine is.


Comments

Post a Comment

Popular posts from this blog

c# - HttpResponseMessage System.InvalidOperationException -

-
quite simple problem i've got easy solve reckon brains. it's tried different queries on google , nothing popped hey that's why here. here error: system.invalidoperationexception basically error thrown on piece of code here string test = response.content.headers.getvalues("location").firstordefault(); location in fiddler looks this: location: https://www.redirecturlishere.com/blah here entire function: private async task<string> getrequest() { //httpcontent postcontent = new stringcontent(post, encoding.ascii, "application/x-www-form-urlencoded"); using (httpresponsemessage response = await httpclient.getasync( "http://www.cant-share-url.com")) { using (httpcontent content = response.content) { string test = response.content.headers.getvalues("location").firstordefault(); } } return ""; ...
Read more

sql - Postgresql error: "failed to find conversion function from unknown to text" -

-
i have following postgresql query: ( select '201405mase04' testid, count(*) totq, count(distinct case when se1 = '' null else se1 end) totse, case when count(*)=0 7 else count(distinct rc) end totrc eivtestitems ti, eivtests t ti.test_id = t.test_id , t.test_type_id = 1 , t.test_id= '201405mase04' , ti.omit <> 1 ), b ( select '201405mase04' testid, count(*) totq eivtestitems ti, eivtests t ti.test_id = t.test_id , t.test_type_id = 1 , t.test_id= '201405mase04' , ti.omit = 1 ), c ( select '201405mase04' testid, count(*) totq eivtestitems ti, eivtests t ti.test_id = t.test_id , t.test_type_id = 1 , t.test_id= '201405mase04' , ti....
Read more