Files
Nim/lib/pure/parseopt.nim
c-blake 551d7b7dc1 Add ability for users to elide ':' or '=' when CLI authors pass a (#7297)
* Add ability for users to elide ':' or '=' when CLI authors pass a
non-empty partial symbol table.  Behavior should be identical to the
old behavior if empty partial symbol tables are passed.  "Partialness"
of the symbol table refers to the fact that one need only specify
option keys that are toggles/booleans/do not take arguments, hence
the "NoArg" suffixes in shortNoArg and longNoArg.

commandLineParams() returns seq[TaintedString], so use that consistently
in getopt() and initOptParser(seq[TaintedString]) dropping the taint at
the quoting stage just as with the paramStr() logic.

Fix capitalization inconsistency of cmdLongOption.

Export OptParser.cmd and OptParser.pos so that, at least *in principle*,
users of this API can handle "--" option processing termination or some
"git-like" sub-command stop word with a separate option sub-syntax.
{ Eg., ``case p.key of "": echo "trailing non-option args: ", p.cmd[p.pos..^1]``
or ``case p.kind of cmdArgument: if p.key == "mysubcmd": ...``. }  Really,
searching for the last delimiter before p.pos is probably needed to frame
the trailing text..Not the nicest API, but still possible with effort.

* Make requested changes from string to seq[char]
(see https://github.com/nim-lang/Nim/pull/7297)

* Document new behavior and elaborate on some special cases.

* NoArg => NoVal to be less ambiguous/more clear.

* Add more documentation and an example snippet.

* Tweak language. Clarify still using ':'/'=' is ok.

* Add a test case for new NoVal behavior.
2018-03-08 08:12:34 +01:00

253 lines
8.9 KiB
Nim

#
#
# Nim's Runtime Library
# (c) Copyright 2015 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
## 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 with default empty ``shortNoVal``/``longNoVal``:
##
## 1. short options - ``-abcd``, where a, b, c, d are names
## 2. long option - ``--foo:bar``, ``--foo=bar`` or ``--foo``
## 3. argument - everything else
##
## When ``shortNoVal``/``longNoVal`` are non-empty then the ':' and '=' above
## are still accepted, but become optional. Note that these option key sets
## must be updated along with the set of option keys taking no value, but
## keys which do take values need no special updates as their set evolves.
##
## When option values begin with ':' or '=' they need to be doubled up (as in
## ``--delim::``) or alternated (as in ``--delim=:``).
##
## The common ``--`` non-option argument delimiter appears as an empty string
## long option key. ``OptParser.cmd``, ``OptParser.pos``, and
## ``os.parseCmdLine`` may be used to complete parsing in that case.
{.push debugger: off.}
include "system/inclrtl"
import
os, strutils
type
CmdLineKind* = enum ## the detected command line token
cmdEnd, ## end of command line reached
cmdArgument, ## argument detected
cmdLongOption, ## a long option ``--option`` detected
cmdShortOption ## a short option ``-c`` detected
OptParser* =
object of RootObj ## this object implements the command line parser
cmd*: string # cmd,pos exported so caller can catch "--" as..
pos*: int # ..empty key or subcmd cmdArg & handle specially
inShortState: bool
shortNoVal: set[char]
longNoVal: seq[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
{.deprecated: [TCmdLineKind: CmdLineKind, TOptParser: OptParser].}
proc parseWord(s: string, i: int, w: var string,
delim: set[char] = {'\x09', ' ', '\0'}): int =
result = i
if s[result] == '\"':
inc(result)
while not (s[result] in {'\0', '\"'}):
add(w, s[result])
inc(result)
if s[result] == '\"': inc(result)
else:
while not (s[result] in delim):
add(w, s[result])
inc(result)
when declared(os.paramCount):
proc quote(s: string): string =
if find(s, {' ', '\t'}) >= 0 and s[0] != '"':
if s[0] == '-':
result = newStringOfCap(s.len)
var i = parseWord(s, 0, result, {'\0', ' ', '\x09', ':', '='})
if s[i] in {':','='}:
result.add s[i]
inc i
result.add '"'
while i < s.len:
result.add s[i]
inc i
result.add '"'
else:
result = '"' & s & '"'
else:
result = s
# we cannot provide this for NimRtl creation on Posix, because we can't
# access the command line arguments then!
proc initOptParser*(cmdline = "", shortNoVal: set[char]={},
longNoVal: seq[string] = @[]): OptParser =
## inits the option parser. If ``cmdline == ""``, the real command line
## (as provided by the ``OS`` module) is taken. If ``shortNoVal`` is
## provided command users do not need to delimit short option keys and
## values with a ':' or '='. If ``longNoVal`` is provided command users do
## not need to delimit long option keys and values with a ':' or '='
## (though they still need at least a space). In both cases, ':' or '='
## may still be used if desired. They just become optional.
result.pos = 0
result.inShortState = false
result.shortNoVal = shortNoVal
result.longNoVal = longNoVal
if cmdline != "":
result.cmd = cmdline
else:
result.cmd = ""
for i in countup(1, paramCount()):
result.cmd.add quote(paramStr(i).string)
result.cmd.add ' '
result.kind = cmdEnd
result.key = TaintedString""
result.val = TaintedString""
proc initOptParser*(cmdline: seq[TaintedString], shortNoVal: set[char]={},
longNoVal: seq[string] = @[]): OptParser =
## inits the option parser. If ``cmdline.len == 0``, the real command line
## (as provided by the ``OS`` module) is taken. ``shortNoVal`` and
## ``longNoVal`` behavior is the same as for ``initOptParser(string,...)``.
result.pos = 0
result.inShortState = false
result.shortNoVal = shortNoVal
result.longNoVal = longNoVal
result.cmd = ""
if cmdline.len != 0:
for i in 0..<cmdline.len:
result.cmd.add quote(cmdline[i].string)
result.cmd.add ' '
else:
for i in countup(1, paramCount()):
result.cmd.add quote(paramStr(i).string)
result.cmd.add ' '
result.kind = cmdEnd
result.key = TaintedString""
result.val = TaintedString""
proc handleShortOption(p: var OptParser) =
var i = p.pos
p.kind = cmdShortOption
add(p.key.string, p.cmd[i])
inc(i)
p.inShortState = true
while p.cmd[i] in {'\x09', ' '}:
inc(i)
p.inShortState = false
if p.cmd[i] in {':', '='} or card(p.shortNoVal) > 0 and p.key.string[0] notin p.shortNoVal:
if p.cmd[i] in {':', '='}:
inc(i)
p.inShortState = false
while p.cmd[i] in {'\x09', ' '}: inc(i)
i = parseWord(p.cmd, i, p.val.string)
if p.cmd[i] == '\0': p.inShortState = false
p.pos = i
proc next*(p: var OptParser) {.rtl, extern: "npo$1".} =
## parses the first or next option; ``p.kind`` describes what token has been
## parsed. ``p.key`` and ``p.val`` are set accordingly.
var i = p.pos
while p.cmd[i] in {'\x09', ' '}: inc(i)
p.pos = i
setLen(p.key.string, 0)
setLen(p.val.string, 0)
if p.inShortState:
handleShortOption(p)
return
case p.cmd[i]
of '\0':
p.kind = cmdEnd
of '-':
inc(i)
if p.cmd[i] == '-':
p.kind = cmdLongOption
inc(i)
i = parseWord(p.cmd, i, p.key.string, {'\0', ' ', '\x09', ':', '='})
while p.cmd[i] in {'\x09', ' '}: inc(i)
if p.cmd[i] in {':', '='} or len(p.longNoVal) > 0 and p.key.string notin p.longNoVal:
if p.cmd[i] in {':', '='}:
inc(i)
while p.cmd[i] in {'\x09', ' '}: inc(i)
p.pos = parseWord(p.cmd, i, p.val.string)
else:
p.pos = i
else:
p.pos = i
handleShortOption(p)
else:
p.kind = cmdArgument
p.pos = parseWord(p.cmd, i, p.key.string)
proc cmdLineRest*(p: OptParser): TaintedString {.rtl, extern: "npo$1".} =
## retrieves the rest of the command line that has not been parsed yet.
result = strip(substr(p.cmd, p.pos, len(p.cmd) - 1)).TaintedString
iterator getopt*(p: var OptParser): tuple[kind: CmdLineKind, key, val: TaintedString] =
## This is an convenience iterator for iterating over the given OptParser object.
## Example:
##
## .. code-block:: nim
## var p = initOptParser("--left --debug:3 -l -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()
p.pos = 0
while true:
next(p)
if p.kind == cmdEnd: break
yield (p.kind, p.key, p.val)
when declared(initOptParser):
iterator getopt*(cmdline: seq[TaintedString] = commandLineParams(),
shortNoVal: set[char]={}, longNoVal: seq[string] = @[]):
tuple[kind: CmdLineKind, key, val: TaintedString] =
## This is an convenience iterator for iterating over command line arguments.
## This creates a new OptParser. See the above ``getopt(var OptParser)``
## example for using default empty ``NoVal`` parameters. This example is
## for the same option keys as that example but here option key-value
## separators become optional for command users:
##
## .. code-block:: nim
## for kind, key, val in getopt(shortNoVal = { 'l' },
## longNoVal = @[ "left" ]):
## 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 == "":
## writeHelp()
##
var p = initOptParser(cmdline, shortNoVal=shortNoVal, longNoVal=longNoVal)
while true:
next(p)
if p.kind == cmdEnd: break
yield (p.kind, p.key, p.val)
{.pop.}