Module parseopt2

This module provides the standard Nim command line parser. It supports one convenience iterator over all command line options and some lower-level features.

Supported syntax:

1. short options - -abcd, where a, b, c, d are names
2. long option - --foo:bar, --foo=bar or --foo
3. argument - everything else

Imports

os, strutils

Types

CmdLineKind = enum
  cmdEnd,                     ## end of command line reached
  cmdArgument,                ## argument detected
  cmdLongOption,              ## a long option ``--option`` detected
  cmdShortOption              ## a short option ``-c`` detected

the detected command line token

OptParser = object of RootObj
  cmd: seq[string]
  pos: int
  remainingShortOptions: string
  kind*: CmdLineKind           ## the dected command line token
  key*, val*: TaintedString     ## key and value pair; ``key`` is the option
                         ## or the argument, ``value`` is not "" if
                         ## the option was given a value

this object implements the command line parser

GetoptResult = tuple[kind: CmdLineKind, key, val: TaintedString]

Procs

proc initOptParser(cmdline: seq[string]): OptParser {.gcsafe, raises: [],
    tags: [ReadIOEffect].}

Initalizes option parses with cmdline. cmdline should not contain argument 0 - program name. If cmdline == nil default to current command line arguments.

proc initOptParser(cmdline: string): OptParser {.gcsafe, deprecated, raises: [],
    tags: [ReadIOEffect].}

Initalizes option parses with cmdline. Splits cmdline in on spaces and calls initOptParser(openarray[string]) Do not use.

proc initOptParser(): OptParser {.raises: [], tags: [ReadIOEffect].}

Initializes option parser from current command line arguments.

proc next(p: var OptParser) {.gcsafe, extern: "npo2$1", raises: [Exception],
                          tags: [RootEffect].}

proc cmdLineRest(p: OptParser): TaintedString {.gcsafe, extern: "npo2$1", deprecated,
    raises: [], tags: [].}

Returns part of command line string that has not been parsed yet. Do not use - does not correctly handle whitespace.

Iterators

iterator getopt(p: var OptParser): GetoptResult {.raises: [Exception],
    tags: [RootEffect].}

This is an convenience iterator for iterating over the given OptParser object. Example:

var p = initOptParser("--left --debug:3 -l=4 -r:2")
for kind, key, val in p.getopt():
  case kind
  of cmdArgument:
    filename = key
  of cmdLongOption, cmdShortOption:
    case key
    of "help", "h": writeHelp()
    of "version", "v": writeVersion()
  of cmdEnd: assert(false) # cannot happen
if filename == "":
  # no filename has been given, so we show the help:
  writeHelp()

iterator getopt(): GetoptResult {.raises: [Exception],
                               tags: [ReadIOEffect, RootEffect].}

This is an convenience iterator for iterating over the command line arguments. This create a new OptParser object. See above for a more detailed example

for kind, key, val in getopt():
  # this will iterate over all arguments passed to the cmdline.
  continue