Issue #19782 has been reported by hurricup (Alexandr Evstigneev). ---------------------------------------- Bug #19782: Ruby operators precedence inconsistency https://bugs.ruby-lang.org/issues/19782 * Author: hurricup (Alexandr Evstigneev) * Status: Open * Priority: Normal * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- Unfortunately I could not find a good documentation regarding ruby operators precedence and associativity, but according to https://ruby-doc.org/3.2.2/syntax/precedence_rdoc.html `&&` has higher precedence than assignment. Meaning that `a && b = c` would be treated as `(a && b) = c` which makes a little sense, but still. But ruby 3.2.2 shows that it works as `a && (b = c)` (if I read it right): ``` def moo(a,b,c) if a && b = c end end puts RubyVM::InstructionSequence.of(method :moo).disasm ``` Gives me ``` == disasm: #<ISeq:moo@/home/hurricup/Projects/untitled/test.rb:1 (1,0)-(5,3)> (catch: false) local table (size: 3, argc: 3 [opts: 0, rest: -1, post: 0, block: -1, kw: -1@-1, kwrest: -1]) [ 3] a@0<Arg> [ 2] b@1<Arg> [ 1] c@2<Arg> 0000 getlocal_WC_0 a@0 ( 2)[LiCa] 0002 branchunless 13 0004 getlocal_WC_0 c@2 0006 dup 0007 setlocal_WC_0 b@1 0009 branchunless 13 0011 putnil 0012 leave ( 5)[Re] 0013 putnil ( 2) 0014 leave ( 5)[Re] ``` For example, perl has well documentation and same rules regarding these two ops: https://perldoc.perl.org/perlop#Operator-Precedence-and-Associativity And if you try: ``` use v5.38; my($var1, $var2, $var3) = (1,2,3); $var1 && $var2 = $var3; say $var1, $var2, $var3; ``` You will get expected: ``` Can't modify logical and (&&) in scalar assignment at /home/hurricup/Projects/untitled/test.pl line 5, near "$var3;" Execution of /home/hurricup/Projects/untitled/test.pl aborted due to compilation errors. ``` Could you please clarify this? Also would be really nice to have documentation on how precedence work, including calls without parens, like `some.thing expr` which precedence is consumed by `expr` here? -- https://bugs.ruby-lang.org/