lambda - Not Function And Function Composition in F# -


is possible f# have function composition between operators.not , standard .net function, instance string.isnullorempty?

in other words, why following lambda expression unacceptable:

(fun x -> not >> string.isnullorempty)

the >> function composition works other way round - passes result of function on left function on right - snippet passing bool isnullorempty, type error. following works:

(fun x -> string.isnullorempty >> not)

or can use reversed function composition (but think >> preferred in f#):

(fun x -> not << string.isnullorempty)

aside, snippet creating function of type 'a -> string -> bool, because ignoring argument x. suppose might want just:

(string.isnullorempty >> not)

-

Popular posts from this blog

debugging - Reference - What does this error mean in PHP? -

what this? this number of answers warnings, errors , notices might encounter while programming php , have no clue how fix. community wiki, invited participate in adding , maintaining list. why this? questions "headers sent" or "calling member of non-object" pop on stack overflow. root cause of questions same. answers questions typically repeat them , show op line change in his/her particular case. these answers not add value site because apply op's particular code. other users having same error can not read solution out of because localized. sad, because once understood root cause, fixing error trivial. hence, list tries explain solution in general way apply. what should here? if question has been marked duplicate of this, please find error message below , apply fix code. answers contain further links investigate in case shouldn't clear general answer alone. if want contribute, please add "favorite" error message, warning or notic...
Read more

How to parse output from sse.client in Python? -

i new python , trying ahead around parsing sse client code. using sse client library . code basic , follows sample exactly. here is: from sseclient import sseclient devid = "xxx" atoken = "xxx" sparkurl = 'https://api.spark.io/v1/devices/' + devid + '/events/?access_token=' + atoken messages = sseclient(sparkurl) msg in messages: print(msg) print(type(msg)) the code runs without problem , see blank lines , sse data coming through. here sample output: <class 'sseclient.event'> {"data":"0 days, 0:54:43","ttl":"60","published_at":"2015-04-09t22:43:52.084z","coreid":"xxxx"} <class 'sseclient.event'> <class 'sseclient.event'> {"data":"0 days, 0:55:3","ttl":"60","published_at":"2015-04-09t22:44:12.092z","coreid":"xxx"} <class ...
Read more