Re: tilde syntax

[Ray Andrews <rayandrews@eastlink.ca>]

On 2024-01-05 06:41, Mark J. Reed wrote:

Running this:


asterisk='*'

echo $asterisk

echo $~asterisk

echo '*'

echo *

... gives me:

*
1 2 3 4 5
*
1 2 3 4 5

So one might say that by default a variable expands with implicit single 
quotes around it?  But the tilde reverts it to 'unquoted' (for lack of a 
better word)?  So in my original, " zsh_case='(#i)' " what I was doing, 
without the tilde, is sending " (#i) " not as an expansion directive, 
but as a literal string?  Yeah, where I crashed and burned was not 
seeing that " (#i) " and " * " are subject to the same rule -- both are 
presumed to be directives but both can also be literal, and when used 
via a variable, they are literal.  Yes?  And this was a design choice at 
variance with shell tradition, so obviously very deliberately chosen?  
Well then, counter intuitive as it is, I'll take it on faith that this 
is the better design.    Subject to further correction:  by George, I 
think I've got it.

Besides: " echo '$asterisk' "  obviously won't do what I might have been 
aiming at.  So the only alternative would be if the tilde worked in 
reverse -- presume expandable but force literal -- and that's merely 
another design choice -- six of one half a dozen of the other -- so we 
have what the devs considered the most convenient :-)  This will fit 
several more pieces into the puzzle, not just one.  zsh is full of these 
invisible differences: is that a directive or is it text?  Sometimes the 
presumption is one, sometimes the other.  This helps me see the 
invisible difference.

Thank you Sensei.