Add --dash-dash-is-rest option to Command

src/cli.toit

@@ -193,6 +193,16 @@ class Command:
   /** The rest arguments. */
   rest_/List
 
+  /**
+  Whether '--' is treated as a regular rest argument.
+
+  When false (the default), '--' stops option parsing and all subsequent
+    arguments become rest arguments.
+  When true, '--' is treated as a normal rest argument and option parsing
+    continues for subsequent arguments.
+  */
+  dash-dash-is-rest_/bool
+
   /** Whether this command should show up in the help. */
   is-hidden_/bool
 
@@ -227,51 +237,52 @@ class Command:
   */
   constructor name --usage/string?=null --help/string?=null --examples/List=[] \
       --aliases/List=[] --options/List=[] --rest/List=[] --subcommands/List=[] --hidden/bool=false \
-      --run/Lambda?=null:
+      --dash-dash-is-rest/bool=false --run/Lambda?=null:
     return Command.private name --usage=usage --help=help --examples=examples \
         --aliases=aliases --options=options --rest=rest --subcommands=subcommands --hidden=hidden \
-        --run=run
+        --dash-dash-is-rest=dash-dash-is-rest --run=run
 
   /**
   Deprecated. Use '--help' instead of '--short-help'.
   */
   constructor name --usage/string?=null --short-help/string --examples/List=[] \
       --aliases/List=[] --options/List=[] --rest/List=[] --subcommands/List=[] --hidden/bool=false \
-      --run/Lambda?=null:
+      --dash-dash-is-rest/bool=false --run/Lambda?=null:
     return Command.private name --usage=usage --short-help=short-help --examples=examples \
         --aliases=aliases --options=options --rest=rest --subcommands=subcommands --hidden=hidden \
-        --run=run
+        --dash-dash-is-rest=dash-dash-is-rest --run=run
 
   /**
   Deprecated. Use '--help' instead of '--long-help'.
   */
   constructor name --usage/string?=null --long-help/string --examples/List=[] \
       --aliases/List=[] --options/List=[] --rest/List=[] --subcommands/List=[] --hidden/bool=false \
-      --run/Lambda?=null:
+      --dash-dash-is-rest/bool=false --run/Lambda?=null:
     return Command.private name --usage=usage --help=long-help --examples=examples \
         --aliases=aliases --options=options --rest=rest --subcommands=subcommands --hidden=hidden \
-        --run=run
+        --dash-dash-is-rest=dash-dash-is-rest --run=run
 
   /**
   Deprecated. Use '--help' with a meaningful first paragraph instead of '--short-help' and '--long-help'.
   */
   constructor name --usage/string?=null --short-help/string --long-help/string --examples/List=[] \
       --aliases/List=[] --options/List=[] --rest/List=[] --subcommands/List=[] --hidden/bool=false \
-      --run/Lambda?=null:
+      --dash-dash-is-rest/bool=false --run/Lambda?=null:
     return Command.private name --usage=usage --short-help=short-help --help=long-help --examples=examples \
         --aliases=aliases --options=options --rest=rest --subcommands=subcommands --hidden=hidden \
-        --run=run
+        --dash-dash-is-rest=dash-dash-is-rest --run=run
 
   constructor.private .name --usage/string?=null --short-help/string?=null --help/string?=null --examples/List=[] \
       --aliases/List=[] --options/List=[] --rest/List=[] --subcommands/List=[] --hidden/bool=false \
-      --run/Lambda?=null:
+      --dash-dash-is-rest/bool=false --run/Lambda?=null:
     usage_ = usage
     short-help_ = short-help
     help_ = help
     examples_ = examples
     aliases_ = aliases
     options_ = options
     rest_ = rest
+    dash-dash-is-rest_ = dash-dash-is-rest
     subcommands_ = subcommands
     run-callback_ = run
     is-hidden_ = hidden

src/completion_.toit

@@ -115,7 +115,14 @@ complete_ root/Command arguments/List -> CompletionResult_:
         all-named-options.clear
         all-short-options.clear
         add-options-for-command_ current-command all-named-options all-short-options
-      past-dashdash = true
+      if not current-command.dash-dash-is-rest_:
+        past-dashdash = true
+        continue.repeat
+      // Treat "--" as a regular rest argument.
+      rest-option := rest-option-for-index_ current-command positional-index
+      if rest-option:
+        (seen-options.get rest-option.name --init=:[]).add arg
+      positional-index++
       continue.repeat
 
     if arg.starts-with "--":

src/help-generator_.toit

@@ -744,7 +744,7 @@ class HelpGenerator:
   write-usage-suffix_ command/Command --has-more-options/bool -> none:
     if not command.subcommands_.is-empty: write_ " <command>"
     if has-more-options: write_ " [<options>]"
-    if not command.rest_.is-empty: write_ " [--]"
+    if not command.rest_.is-empty and not command.dash-dash-is-rest_: write_ " [--]"
     command.rest_.do: | option/Option |
       type := option.type
       option-str/string := ?

src/parser_.toit

@@ -124,10 +124,13 @@ class Parser_:
           remaining := ["--"] + arguments[index..]
           parse group.default_ remaining block
           return
-        rest.add-all arguments[index ..]
-        break  // We're done!
+        if not command.dash-dash-is-rest_:
+          rest.add-all arguments[index ..]
+          break  // We're done!
+        // Treat "--" as a regular rest argument.
+        rest.add argument
 
-      if argument.starts-with "--":
+      else if argument.starts-with "--":
         value/string? := null
         // Get the option name.
         split := argument.index-of "="

tests/dashdash_test.toit

@@ -6,16 +6,43 @@ import cli
 import expect show *
 
 main:
+  test-dashdash-separator
+  test-no-allow-dashdash
+  test-no-allow-dashdash-with-options
+
+test-dashdash-separator:
   root := cli.Command "root"
-    --rest=[
-      cli.Option "first" --required,
-      cli.Option "arg" --multi
-    ]
-    --run=:: test-dashdash it
+      --rest=[
+        cli.Option "first" --required,
+        cli.Option "arg" --multi,
+      ]
+      --run=:: | invocation/cli.Invocation |
+        expect-equals "prog" invocation["first"]
+        expect-list-equals ["arg1", "arg2", "arg3"] invocation["arg"]
   root.run ["--", "prog", "arg1", "arg2", "arg3"]
 
-test-dashdash invocation/cli.Invocation:
-  first := invocation["first"]
-  rest := invocation["arg"]
-  expect-equals "prog" first
-  expect-list-equals ["arg1", "arg2", "arg3"] rest
+test-no-allow-dashdash:
+  // When --allow-dash-dash is false, "--" becomes a regular rest argument.
+  root := cli.Command "root"
+      --dash-dash-is-rest
+      --rest=[
+        cli.Option "arg" --multi,
+      ]
+      --run=:: | invocation/cli.Invocation |
+        expect-list-equals ["--", "foo", "bar"] invocation["arg"]
+  root.run ["--", "foo", "bar"]
+
+test-no-allow-dashdash-with-options:
+  // Options after "--" are still parsed when allow-dash-dash is false.
+  root := cli.Command "root"
+      --dash-dash-is-rest
+      --options=[
+        cli.Flag "verbose" --short-name="v",
+      ]
+      --rest=[
+        cli.Option "arg" --multi,
+      ]
+      --run=:: | invocation/cli.Invocation |
+        expect invocation["verbose"]
+        expect-list-equals ["--", "foo"] invocation["arg"]
+  root.run ["--", "foo", "--verbose"]