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Re: differences in Q.-removal, var-expansion and allowed characters in f

From: Linda Walsh
Subject: Re: differences in Q.-removal, var-expansion and allowed characters in fn & var names
Date: Sun, 10 Jan 2016 12:50:55 -0800
User-agent: Thunderbird

Andreas Schwab wrote:

That's not the same statement.  The same statement would be

def='function $fn () { echo $fn ; }'
I know what you mean, but,

Yeah, sorta but I want it to do variable expansion AND quote removal.

I.e. using a var or DQ of the object-name, "a", works in declare.

Work ok:
   > declare  a=1         # OR
   > declare "a"=1   and  declare 'a'=1     # OR
   > declare 'a=1'   and  declare "a=1"     # OR
   > x=a
   > declare   $x=1                         # OR
   > declare "$x"=1  and  declare "$x=1"    # All "work"

With eval, I can use:
   > eval declare a=1,    eval 'declare a=1'   or   eval "declare a=1"
   > x=a  &&
   > eval declare $x=1    eval 'declare $x=1'  or   eval "declare $x=1"

   But w/functions, none of the 1st group will work

Vs. w/function, only
   > eval 'function a { echo fna; }'   # OR
   > eval "function a { echo fna; }"   # OR
   > x=a                               # AND w/eval: only whole statements:
   > eval 'function $x { echo fn$x; }'   # OR
   > eval "function $x { echo fn$x; }"   # work.

None of the partial- or no- quote forms work.

While quoting rules for "Identifier Names" used w/"declare" are more
flexible/tolerant than those used for "functions", the *opposite*
is true for what characters are allowed in "function names" v.
"varnames".  I.e names for functions allow UTF-8 but names
for variables do not.  Using a name with a Greek alpha + a Roman '4':

   > declare ɑⅣ=1                                   # doesn't work
   -bash: declare: `ɑⅣ=1': not a valid identifier
> function ɑⅣ { echo fn_ɑⅣ; } # same name used for func
   > ɑⅣ
   fn_ɑⅣ                                            # UTF8 ok in fn-names

But this seems like it shouldn't work (number before the alpha):

   > function Ⅳɑ { echo fn_Ⅳɑ; }                   # function "4a"
   > Ⅳɑ

Even though the allowed characters for a "variable" Name are the
same as the characters allowed for "function" names.  Why the
differences (in both cases?), also should a func starting with
a number be allowed in function names?


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