tvl-depot/nix/netstring/attrsToKeyValList.nix
Profpatsch 7e888c3c7b feat(nix): add basic netstring nix generation functions
Moving to toplevel so I can use them with `runExecline`. They should
be pretty atomic, and are proven to work (tests are still in my user
dir, since they test the producers indirectly via the python parser
and I don’t want to pull it out right now).

Change-Id: Id0baa3adcb2ec646458a104c7868c2889b8c64f5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3054
Reviewed-by: Profpatsch <mail@profpatsch.de>
Tested-by: BuildkiteCI
2021-04-24 09:54:34 +00:00

33 lines
953 B
Nix

{ depot, lib, ... }:
# Convert an attrset of strings to a list of key/value netstring pairs.
# A good minimally viable json replacement if all you need is to iterate.
# You can use e.g. `forstdin -Ed '' item` in execline to split the items
# and then get the key and value via `multidefine -d '' $item { key value }`
#
# Example:
# { foo = "bar"; x = "abc"; }
# => "12:3:foo,3:bar,,10:1:x,3:abc,,"
#
# Example with runExecline:
# nix.runExecline "test" {
# stdin = nix.netstring.attrsToKeyValList {
# foo = "bar";
# x = "abc";
# };
# } [
# "forstdin" "-Ed" "" "item"
# "multidefine" "-d" "" "$item" [ "key" "value" ]
# "${pkgs.coreutils}/bin/echo" "\${key} -> \${value}"
# ]
# will print:
# foo -> bar
# x -> abc
attrs:
lib.concatStrings
(lib.mapAttrsToList
(k: v: depot.nix.netstring.fromString
( depot.nix.netstring.fromString k
+ depot.nix.netstring.fromString v))
attrs)