fix --resources [all]

Allow passing `-r` without argument to display all resources.

Ref: #81
Co-authored-by: tomasohara

README.md

@@ -11,7 +11,7 @@ colout — Color Up Arbitrary Command Output
 
 ## Synopsis
 
-`colout [-h] [-r RESOURCE]`
+`colout [-h] [-r [RESOURCE]]`
 
 `colout [-g] [-c] [-l min,max] [-a] [-t] [-T DIR] [-P DIR] [-d COLORMAP] [-s] [-e CHAR] [-E CHAR] [--debug] PATTERN [COLOR(S) [STYLE(S)]]`
 
@@ -145,10 +145,10 @@ $ sudo apt-get/aptitude install colout
   Also, external palettes are converted from RGB to 256-ANSI and will thus not work if you use
   them as default colormaps for a 8-colors mode special color.
 
-* `-r TYPE(S)`, `--resources TYPE(S)`:
+* `-r [TYPE(S)]`, `--resources [TYPE(S)]`:
   Print the names of available resources. Use a comma-separated list of resources names
   (styles, colors, special, themes, palettes, colormaps or lexers),
-  use 'all' to print everything.
+  use 'all' (or no argument) to print all resources.
 
 * `-s`, `--source`:
   Interpret PATTERN as source code readable by the Pygments library. If the first letter of PATTERN

colout/colout.py

@@ -889,6 +889,10 @@ def _args_parse(argv, usage=""):
     parser.add_argument("--debug", action="store_true",
             help="Debug mode: print what's going on internally, useful if you want to check what features are available.")
 
+    # HACK: Mock up "--resources ALL" if just "--resources" on command line
+    if (len(sys.argv) == 2 and (sys.argv[1] in ["-r", "--resources"])):
+        sys.argv.append("ALL")
+
     args = parser.parse_args()
 
     return args.pattern[0], args.color, args.style, args.groups, \