[RFC PATCH 02/28] cli: Add LIL shell

Kostas Michalopoulos badsector at runtimeterror.com
Tue Jul 6 18:09:50 CEST 2021


On 7/6/2021 6:43 PM, Tom Rini wrote:
> I don't know if it's right either.  But drawing on my comment just now
> and above about complex boot scripts, I also don't know if "it's sh but
> quirky and incomplete, WHY DOESN'T THIS WORK RIGHT" is better than "It's
> TCL?  I don't know that, let me hit stackoverflow and do a little
> reading" as would be the common experience.  Especially if we document
> up-front what the quirks we have are.

I think the same would happen with Tcl and LIL. LIL might look similar 
to Tcl (and it is inspired by it), but it doesn't have the same syntax. 
A big difference comes from how variables are parsed with LIL allowing 
more variables symbols than Tcl without requiring escaping which affects 
some uses like expr, so e.g. in Tcl this

     set a 10 ; set b 20 ; expr $a+$b

will give back 30 however in LIL will give back 20. This is because Tcl 
parses "$a+$b" as "$a" "+" "$b" whereas LIL parses it as "$a+" "$b", 
evaluates "$a+" as an empty string (there isn't any "a+" variable), "$b" 
as 20 and then just runs expr with the single argument "20".

Kostas


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