Re: interpreting a strongly typed regexp constant variable as literal regular expression?

[Manuel Collado]

El 31/05/2020 a las 23:12, pjfarley3@earthlink.net escribió:
> ISTM that it is the requirement for the "case" part of the switch
> statement to be a *constant* that drove at least part of the
> misunderstanding here.
>
> I just reviewed the relevant sections of the gawk 5.0 documentation
> myself, and in the section on "strongly typed" regular expressions in
> section 6.1.2.2 there is a link to the switch statement section, but
> nowhere in the documentation of the switch statement is there an
> example of the use of a strongly typed regular expression as a "case"
> constant value.  Perhaps there should be such an example there.

Section "7.4.5 The switch Statement"

"Each case contains a single constant, be it numeric, string, or regexp.
The switch expression is evaluated, and then each case’s constant is
compared against the result in turn. The type of constant determines
the comparison: numeric or string do the usual comparisons. A regexp
constant does a regular expression match against the string value of
the original expression."

Please note the explicit mention of the behavior of a regexp constant as 
a case label.

HTH.
--
Manuel Collado - http://mcollado.z15.es