Why does $'…' not expand inside "…"?

Why does $'…' not expand inside "…"?

[Nikolai Weibull]

Why does $'…' not expand inside "…"?

It’s not, as far as I can tell, mentioned in the documentation.

Re: ( Text in unknown character set UTF-8 not shown )

[Bart Schaefer]

On Dec 22,  9:48pm, Nikolai Weibull wrote:
}
} Why does $'...' not expand inside "..."?

Because it doesn't in any of the shells that introduced it before
zsh had it.

I believe the reasoning is that double-quote is allowed to appear
inside $'...' and to expand $'...' inside double-quotes creates a
parsing conflict.  "How does this $'with " embeded' parse?"

} It's not, as far as I can tell, mentioned in the documentation.

The documentation for zsh tends to omit things that are assumed
knowledge, particularly when a concept or feature originates from
another source -- because if you didn't already know about it from
the original source, why did you even think to use it?

This is an acknowledged shortcoming that is addressed piecemeal.

Re: ( Text in unknown character set UTF-8 not shown )

[Bart Schaefer]

On Feb 24, 10:56am, dipakgaigole wrote:
} 
} Before posting the question, I had a look at the glob options as well
} as the NOMATCH option, but the description of NOMATCH option was
} confusing.

The name of the option comes from a csh variable that can be set.  It
was therefore originally "nonomatch".  Many years ago, though, zsh
added the ability to turn *off* any option by prefixing its name with
an additional "no".  Eventually it was viewed as silly that one would
thus e.g. "setopt nononomatch"; so all the options that *already* had
a "no" prefix were renamed to drop one "no" and reverse their boolean
state (including, therefore, their default-at-startup boolean state).

In this case that left us with "nomatch" -- and the documentation also
had to be reversed, of course, which didn't always work as well as when
documenting the original name and state.