Re: more efficient AS_EXIT

[Eric Blake]

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According to Ralf Wildenhues on 11/22/2008 6:13 AM:
>>  exit_missing_arg='
>> -  AS_ECHO(["$as_me: option \`$[1]'\'' requires an argument"]) >&2
>> -  AS_ECHO(["$help"]) >&2
>> -  AS_EXIT([1])
>> -' # restore font-lock: "
>> +  m4_bpatsubst([AS_ERROR([option `$[1]' requires an argument$as_nl$help])],
>> +    ['], ['\\''])'
> 
> Why is that m4_bpatsubst needed here ...

Because it is in a single-quoted context (exit_missing_arg='text'), which
will later be used as
  eval "$exit_missing_arg"

I suppose it could also be written:

exit_missing_arg="
  AS_ESCAPE([AS_ERROR([option `$[1]' requires an argument$as_nl$help])])"

so that the bpatsubst is done under the hood by AS_ESCAPE.

>> +       AS_ERROR([invalid option `$[1]'$as_nl$help]) ;; #`
> 
> ... but not here?

Because that is used literally (AS_ERROR supplies the double-quote context
around its arguments).

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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