* README.EXT, README.EXT.ja: Improve the document about

  rb_scan_args().


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@22421 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 18 insertions, 9 deletions

diff --git a/README.EXT b/README.EXT
index 6364ab7a80..f1504021ba 100644
--- a/README.EXT
+++ b/README.EXT
@@ -690,18 +690,27 @@ pre-arg-spec   := num-of-leading-mandatory-args [num-of-optional-args]
 post-arg-spec  := sym-for-variable-length-args [num-of-trailing-mandatory-args]
 block-arg-spec := sym-for-block-arg
 
-num-of-leading-mandatory-args  := DIGIT  ; -- the number of the leading mandatory arguments
-num-of-optional-args           := DIGIT  ; -- the number of the following optional arguments
-sym-for-variable-length-args   := "*"    ; -- indicates that the following variable length
-                                         ;    arguments are captured as a Ruby array
-num-of-trailing-mandatory-args := DIGIT  ; -- the number of the trailing mandatory arguments
-sym-for-block-arg              := "&"    ; -- indicates that the iterator block should be
-                                         ;    captured if given
+num-of-leading-mandatory-args  := DIGIT ; The number of leading
+                                        ; mandatory arguments
+num-of-optional-args           := DIGIT ; The number of optional
+                                        ; arguments
+sym-for-variable-length-args   := "*"   ; Indicates that variable
+                                        ; length arguments are
+                                        ; captured as a ruby array
+num-of-trailing-mandatory-args := DIGIT ; The number of trailing
+                                        ; mandatory arguments
+sym-for-block-arg              := "&"   ; Indicates that an iterator
+                                        ; block should be captured if
+                                        ; given
 --
 
 For example, "11" means that the method requires at least one
-argument, and at most receives two arguments.  For omitted arguments,
-variables are set to Qnil.
+argument, and at most receives two (1+1) arguments.  So, the format
+string must be followed by two variable references, which are to be
+set to captured arguments.  For omitted arguments, variables are set
+to Qnil.  NULL can be put in place of a variable reference, which
+means the corresponding captured argument(s) does not need to be set.
+
 
 Methods with an arbitrary number of arguments can receive arguments
 by Ruby's array, like this: