Hello, My struggles with regexp is going and I have another problem. I read closely syntax page of RE2 (https://github.com/google/re2/wiki/Syntax) and I still not sure if I understand one example from regexp package.
In example in method func (*Regexp) FindIndex (https://pkg.go.dev/regexp@go1.17#Regexp.FindIndex) we have line pattern := regexp.MustCompile(`(?m)(?P<key>\w+):\s+(?P<value>\w+)$`) Does (?m) set value of flag m to true and if I want set it to false I should write (?-m) or not? By default m should be false, but as example it is fine. As a side note, this regular expression is used in other examples, when we need <key> and <value>, but looks unnecessary complex for method FindIndex. I guess `(?m)\w+:\s+\w+$` would work fine. Am I wrong? Best Kamil środa, 1 września 2021 o 12:29:58 UTC+2 Kamil Ziemian napisał(a): > Kurtis Rader, peterGo thank you for the answers. I probably need to learn > more about RPC protocols, for now I can only expand acronym. But this point > with ignoring leading zeros is clear enough. And probalby more "elementary > (and stupid)?" questions is comming. > > Kamil > poniedziałek, 30 sierpnia 2021 o 03:02:51 UTC+2 peterGo napisał(a): > >> >> >> K, >> >> For a finite, unsigned binary number, ignoring leading zeros, how many >> binary digits (the length in bits) are needed to represent a number? >> >> Peter >> On Sunday, August 29, 2021 at 4:07:41 PM UTC-4 kziem...@gmail.com wrote: >> >>> Thank for explanation, but I don't understand "But how many bits do you >>> need to represent 0? The question is malformed as there are no set bits in >>> the used representation of 0.". Why this is malformed questions? When I >>> think of coding 1, I think about thaking one bit with 1 inside and when it >>> goes to 0, I would take one bit with 0 inside. >>> >>> K. >>> piątek, 27 sierpnia 2021 o 07:14:45 UTC+2 Volker Dobler napisał(a): >>> >>>> On Thursday, 26 August 2021 at 22:17:55 UTC+2 kziem...@gmail.com wrote: >>>> >>>>> Another topic. I needed to check package "math/bits" (learning about >>>>> Go can lead us in such places quite fast) and I'm confused about function >>>>> "Len(x uint) int". In its description we have ( >>>>> https://pkg.go.dev/math/bi...@go1.17 >>>>> <https://pkg.go.dev/math/bits@go1.17>) >>>>> BEGINNING >>>>> Len returns the minimum number of bits required to represent x; the >>>>> result is 0 for x == 0. >>>>> END >>>>> I have no problem with using function that says 0 can be encoded in 0 >>>>> bits, but it is still odd. Maybe it is connected to something done under >>>>> the hood, about which I don't know a thing? Does anyone know why this >>>>> choose was made? >>>> >>>> >>>> No, the description doesn't say that 0 can be encoded in 0 bits: >>>> It says that Len(0) returns 0. >>>> If you want Len to be a total function you must return a value for >>>> every input. >>>> For most inputs the value is strictly determined by what the functions >>>> does >>>> (number of bits needed to represent), so Len(9) == 3. But how many bits >>>> do you need to represent 0? The question is malformed as there are no >>>> set bits in the used representation of 0. One could have declared >>>> "Len(0) returns -42" >>>> but this makes no sense at all. Having Len(0)==0 results in >>>> Len(a) <= Len(b) if a < b without having to invent totally arbitrary >>>> values for Len(0). >>>> >>>> You probably should not overinterpret Go's documentation. >>>> This is not lyric. "the result is 0 for x == 0" has no hidden meaning. >>>> >>>> V. >>>> >>> -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/7ae1e154-76f8-4677-a6d3-53e010692a3an%40googlegroups.com.
