Dear brethren,

please help me understand either

• what is meant °
• what I'm missing
• if this a bug

from perlop#Quote-and-Quote-like-Operators

 
\x{263A}     [1,8]  hex char          (example shown: SMILEY)
\x{ 263A }          Same, but shows optional blanks inside and
                    adjoining the braces
[download]

  DB<55> p join ",",map {ord} split //, "\x{ 41 }"                    
+                                                  
0                                                                     
+                                                    
  DB<56> p join ",",map {ord} split //, "\x{41}"                      
+                                                  
65                                                                    
+                                                    
  DB<57> p join ",",map {ord} split //, "\x{263A}"                    
+                                                  
9786                                                                  
+                                                    
  DB<58> p join ",",map {ord} split //, "\x{ 263A }"                  
+                                                  
0                                                                     
+                                                    
  DB<59> p "\x{41}"                                                   
+                                                  
A                                                                     
+                                                    
  DB<60> p "\x{ 41 }"                                                 
+                                                  
^@
[download]

tested with strawberry perl 5.032001 on win

Question: In which way is this

"Same, but shows optional blanks inside and adjoining the braces" ?

update

°) OK - ironically - reading the footnotes help

https://perldoc.perl.org/perlop#%5B1%5D

Note that any escape sequence using braces inside interpolated constructs may have optional blanks (tab or space characters) adjoining with and inside of the braces, as illustrated above by the second \x{ } example.

[1] The result is the character specified by the hexadecimal number between the braces. See "8" below for details on which character.

Blanks (tab or space characters) may separate the number from either or both of the braces.

Otherwise, only hexadecimal digits are valid between the braces. If an invalid character is encountered, a warning will be issued and the invalid character and all subsequent characters (valid or invalid) within the braces will be discarded.

If there are no valid digits between the braces, the generated character is the NULL character (\x{00}). However, an explicit empty brace (\x{}) will not cause a warning (currently).

update

and activating warnings shows the bug, somehow the blank is not recognized.

  DB<65> use warnings; "\x{ 263A }"                                   
+                                                  
Non-hex character ' ' terminates \x early.  Resolved as "\x{00}" at (e
+val
[download]

update

different warnings by version ... this is getting weirder and weirder

• ActiveState 5.24

  C:\tmp>%PERL% -w
  print $];
  print "\x{ 41 }";
  Illegal hexadecimal digit ' ' ignored at - line 2.
  __END__
  5.024001
  [download]

• Strawberry 5.32

  C:\tmp>%PERL_532% -w
  print $];
  print "\x{ 41 }";
  Non-hex character ' ' terminates \x early.  Resolved as "\x{00}" at - 
  +line 2.
  __END__
  5.032001
  [download]

could someone please test this on linux?

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