Use a different operator for cstring stringification

[dom96]

Using & is a strange choice and is confusing

[timotheecour]

from https://irclogs.nim-lang.org/27-01-2018.html#12:48:00

Araq should have used $! or something, not freaking &

instead of an operator, can we just use toCstring, as used in stdlib ?
users can always define their own operators in their own code if they want something shorter

my recommendation:

• introduce toCstring
• mark those & procs as deprecated: use `toCstring` and remove all uses of & in karax in the same PR

note

one problem with using operators for this is that parsing rules makes it awkward to use in UFCS/MCS chains, eg:

# what i want:
let a = foo.bar.toString.toLower

# what i have to use:
let a = ($foo.bar).toLower
let a = foo.bar.`$`.toLower

although it's nice to have a short, standard name for stringification; not sure if there's a better solution though.

links

karax/jstrutils.nim:19:6:proc `&`*(a, b: cstring): cstring {.importcpp: "(# + #)", nodecl.}
karax/jstrutils.nim:21:6:proc `&`*(s: int): cstring {.importcpp: "((#)+'')", nodecl.}
karax/jstrutils.nim:22:6:proc `&`*(s: bool): cstring {.importcpp: "((#)+'')", nodecl.}
karax/jstrutils.nim:23:6:proc `&`*(s: float): cstring {.importcpp: "((#)+'')", nodecl.}
karax/jstrutils.nim:25:6:proc `&`*(s: cstring): cstring {.importcpp: "(#)", nodecl.}
karax/kajax.nim:7:21:import jsffi except `&`
karax/reactive.nim:159:7:lift2 `&`
karax/vstyles.nim:348:12:  template `&`(x: untyped): untyped = $x

[Araq]

introduce toCstring

toCstring is too verbose, IMHO. I picked an operator because anything else was too verbose. We should use a different operator but I don't know which one.

[timotheecour]

since there's nothing karax specific about & or toCstring or whatever name should be used, and since stdlib already has toCstring procs defined, I feel a stdlib module (std/cstrings? std/cdollars?) should standardize it (and work for c, js backends); then karax can reuse it for nim versions > 1.5.1 else redefine it.

options:

• cstr ? (no existing hits in stdlib, at least no relevant ones)
• if an operator, IMO it should start with $; $$ would make sense but std/marshal uses it; $^ or similar could work

I still prefer cstr though (not much longer that $$, and works better in MCS/UFCS)

[geotre]

@Araq let me know if one of these works and I will PR a backwards compatible change (with deprecation message) to karax?

[Araq]

cstr is short for c string but that name is widely regarded to be mistake now too, so how about jss?