Make parseopt available on all backends (#17009)

* Make parseopt available on all backends

* fix spaces

* fix getopt and update prelude

* no crazy unnecessary version checks, use doAssert

changelog.md

@@ -147,6 +147,14 @@ provided by the operating system.
   issues like https://github.com/nim-lang/Nim/issues/13063 (which affected error messages)
   for modules importing `std/wrapnils`.
 
+- `parseopt.initOptParser` has been made available and `parseopt` has been
+  added back to `prelude` for all backends. Previously `initOptParser` was
+  unavailable if the `os` module did not have `paramCount` or `paramStr`,
+  but the use of these in `initOptParser` were conditionally to the runtime
+  arguments passed to it, so `initOptParser` has been changed to raise
+  `ValueError` when the real command line is not available. `parseopt` was
+  previously excluded from `prelude` for JS, as it could not be imported.
+
 ## Language changes
 
 - `nimscript` now handles `except Exception as e`.

lib/prelude.nim

@@ -16,8 +16,6 @@
 ## Same as:
 ##
 ## .. code-block:: nim
-##   import os, strutils, times, parseutils, hashes, tables, sets, sequtils
+##   import os, strutils, times, parseutils, hashes, tables, sets, sequtils, parseopt
-##   when not defined(js): import parseopt
 
-import os, strutils, times, parseutils, hashes, tables, sets, sequtils
+import os, strutils, times, parseutils, hashes, tables, sets, sequtils, parseopt
-when not defined(js): import parseopt

lib/pure/parseopt.nim

@@ -192,17 +192,14 @@ proc parseWord(s: string, i: int, w: var string,
       add(w, s[result])
       inc(result)
 
-when declared(os.paramCount):
-  # 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] = @[];
                     allowWhitespaceAfterColon = true): OptParser =
   ## Initializes the command line parser.
   ##
   ## If ``cmdline == ""``, the real command line as provided by the
-    ## ``os`` module is retrieved instead.
+  ## ``os`` module is retrieved instead if it is available. If the
+  ## command line is not available, a `ValueError` will be raised.
   ##
   ## ``shortNoVal`` and ``longNoVal`` are used to specify which options
   ## do not take values. See the `documentation about these
@@ -226,9 +223,15 @@ when declared(os.paramCount):
   if cmdline != "":
     result.cmds = parseCmdLine(cmdline)
   else:
-      result.cmds = newSeq[string](os.paramCount())
+    when declared(paramCount):
-      for i in countup(1, os.paramCount()):
+      result.cmds = newSeq[string](paramCount())
-        result.cmds[i-1] = os.paramStr(i)
+      for i in countup(1, paramCount()):
+        result.cmds[i-1] = paramStr(i)
+    else:
+      # we cannot provide this for NimRtl creation on Posix, because we can't
+      # access the command line arguments then!
+      doAssert false, "empty command line given but" &
+        " real command line is not accessible"
 
   result.kind = cmdEnd
   result.key = ""
@@ -240,8 +243,10 @@ when declared(os.paramCount):
   ## Initializes the command line parser.
   ##
   ## If ``cmdline.len == 0``, the real command line as provided by the
-    ## ``os`` module is retrieved instead. Behavior of the other parameters
+  ## ``os`` module is retrieved instead if it is available. If the
-    ## remains the same as in `initOptParser(string, ...)
+  ## command line is not available, a `ValueError` will be raised.
+  ## Behavior of the other parameters remains the same as in
+  ## `initOptParser(string, ...)
   ## <#initOptParser,string,set[char],seq[string]>`_.
   ##
   ## See also:
@@ -263,9 +268,15 @@ when declared(os.paramCount):
     for i in 0..<cmdline.len:
       result.cmds[i] = cmdline[i]
   else:
-      result.cmds = newSeq[string](os.paramCount())
+    when declared(paramCount):
-      for i in countup(1, os.paramCount()):
+      result.cmds = newSeq[string](paramCount())
-        result.cmds[i-1] = os.paramStr(i)
+      for i in countup(1, paramCount()):
+        result.cmds[i-1] = paramStr(i)
+    else:
+      # we cannot provide this for NimRtl creation on Posix, because we can't
+      # access the command line arguments then!
+      doAssert false, "empty command line given but" &
+        " real command line is not accessible"
   result.kind = cmdEnd
   result.key = ""
   result.val = ""
@@ -366,6 +377,7 @@ proc next*(p: var OptParser) {.rtl, extern: "npo$1".} =
     inc p.idx
     p.pos = 0
 
+when declared(quoteShellCommand):
   proc cmdLineRest*(p: OptParser): string {.rtl, extern: "npo$1".} =
     ## Retrieves the rest of the command line that has not been parsed yet.
     ##
@@ -442,8 +454,7 @@ iterator getopt*(p: var OptParser): tuple[kind: CmdLineKind, key,
     if p.kind == cmdEnd: break
     yield (p.kind, p.key, p.val)
 
-when declared(initOptParser):
+iterator getopt*(cmdline: seq[string] = @[],
-  iterator getopt*(cmdline: seq[string] = commandLineParams(),
                   shortNoVal: set[char] = {}, longNoVal: seq[string] = @[]):
             tuple[kind: CmdLineKind, key, val: string] =
   ## Convenience iterator for iterating over command line arguments.

tests/js/tstdlib_imports.nim

@@ -46,7 +46,7 @@ import std/[
 
   # Parsers:
   htmlparser, json, lexbase, parsecfg, parsecsv, parsesql, parsexml,
-  # fails: parseopt
+  parseopt,
 
   # XML processing:
   xmltree, xmlparser,

tests/test_nimscript.nims

@@ -48,7 +48,7 @@ import std/[
 
   # Parsers:
   htmlparser, json, lexbase, parsecfg, parsecsv, parsesql, parsexml,
-  # fails: parseopt
+  parseopt,
 
   # XML processing:
   xmltree, xmlparser,
@@ -114,3 +114,7 @@ block:  # cpDir, cpFile, dirExists, fileExists, mkDir, mvDir, mvFile, rmDir, rmF
   doAssert dirExists(subDir2)
   mvDir(subDir2, subDir)
   rmDir(dname)
+
+block:
+  # check parseopt can get command line:
+  discard initOptParser()