From: tagomoris@... Date: 2017-09-15T16:32:02+00:00 Subject: [ruby-core:82819] [Ruby trunk Feature#12753] Useful operator to check bit-flag is true or false Issue #12753 has been updated by tagomoris (Satoshi TAGOMORI). How about `bitmask_test?` or `bitflag_test?` shugo (Shugo Maeda) wrote: > Shugo Maeda wrote: > > IBM InfoSphere and MS FoxPro have BITTEST(), but its second argument is the bit position > > to be tested. > > > > http://www.ibm.com/support/knowledgecenter/SSZJPZ_11.3.0/com.ibm.swg.im.iis.ds.basic.doc/topics/r_dsbasic_BITTEST_function.html > > https://msdn.microsoft.com/en-us/library/aa977348(v=vs.71).aspx > > > > This behavior seems to fit the name bittest, compared to the proposed one. > > I didn't mean to propose this behavior. > I just meant to point out that `bittest?` may not be suitable for the proposed behavior. ---------------------------------------- Feature #12753: Useful operator to check bit-flag is true or false https://bugs.ruby-lang.org/issues/12753#change-66697 * Author: tagomoris (Satoshi TAGOMORI) * Status: Open * Priority: Normal * Assignee: * Target version: ---------------------------------------- Ruby's 0 is truthy value. It's useful for many cases, but it's confusing and I made many bugs when I'm writing code to handle binary data, because my thought is almost same with one to write C code in such situation. ```ruby n = get_integer_value if n & 0b10100000 # code for the case when flag is true else # never comes here :( end ``` IMO it's very useful to have methods for such use-cases, like `#and?` and `#xor?` (`#or?` looks not so useful... I can't imagine the use case of this operator, but it's better to have for consistency). ```ruby n = get_integer_value case when n.and?(0b10000000) # negative signed char when n.and?(0b01110000) # large positive else # small positive end ``` -- https://bugs.ruby-lang.org/ Unsubscribe: