Example:

import src/cliche
import std/strutils
# Use https://nim-lang.github.io/Nim/os.html#commandLineParams
block:
  type Food = enum PIZZA, TACO  # Enum from CLI.
  # let real = commandLineParams()
  let fake = @["--a=1", "--v_1=9.9", "--v2=1", "--v3=2", "--v4=X", "--v5=t", "--v6=z", "--v7=true", "--food=PIZZA", "--help"]
  fake.getOpt (a: int.high, v_1: 3.14, v2: 9'u64, v3: -9'i64, v4: "a", v5: '4', v6: cstring"b", v7: false, missing: 42, food: TACO)
  doAssert a == 1
  doAssert v_1 == 9.9
  doAssert v2 == 1'u64
  doAssert v3 == 2'i64
  doAssert v4 == "X"
  doAssert v5 == 't'
  doAssert v6 == cstring"z"
  doAssert v7 == true
  doAssert missing == 42 # missing is not in fake, fallback to default value 42.
  doAssert food is Food and food == PIZZA  # food is Food.PIZZA
block:
  let fake = @["--a=false", "--b=5", "--c=1", "--d=2.0", "--e=3", "--f=128"]
  fake.getOpt (a: true, b: 9.Positive, c: 5.cint, d: 0.0.float32, e: 0.Natural, f: 255.byte)
  doAssert a == false
  doAssert b == 5.Positive
  doAssert c == 1.cint
  doAssert d == 2.0.float32
  doAssert e == 3.Natural
  doAssert f == 128.byte

Auto-Generated --help (Can be parsed as TSV):

$ example --help
key     type    default
--a=    int     int.high
--v_1=  float   3.14
--v2=   uint    9'u64
--v3=   int     -9'i64
--v4=   string  "a"
--v5=   char    '4'
--v6=   string  cstring"b"
--missing=      int     42
--help  ?       Some Help Message Here!

Macros

macro getOpt(source: seq[string]; variables: untyped; helpMessage: static[string] = ""; sepa: static[char] = '='; prefix: static[char] = '-'; useEnvVars: static[bool] = false)