MATRIX DATA: Fully implement.

[pspp] / doc / flow-control.texi

diff --git a/doc/flow-control.texi b/doc/flow-control.texi
index c68923f8c052f35fe39cb3255daa2375e554a75b..23539bcfb67e24b420f4b6669a95172a05178051 100644 (file)
--- a/doc/flow-control.texi
+++ b/doc/flow-control.texi
@@ -243,8 +243,8 @@ A @dfn{positional} argument has a required value that follows the
 macro's name.  Use the @code{!POSITIONAL} keyword to declare a
 positional argument.
 
-When a macro is called, every positional argument must be given a
-value in the same order as the defintion.
+When a macro is called, the positional argument values appear in the
+same order as their definitions, before any keyword argument values.
 
 References to a positional argument in a macro body are numbered:
 @code{!1} is the first positional argument, @code{!2} the second, and
@@ -266,10 +266,7 @@ FREQUENCIES /VARIABLES=!1.
 @item
 A @dfn{keyword} argument has a name.  In the macro call, its value is
 specified with the syntax @code{@i{name}=@i{value}}.  The names allow
-keyword argument values to take any order in the call, and even to be
-omitted.  When one is omitted, a default value is used: either the
-value specified in @code{!DEFAULT(@i{value})}, or an empty value
-otherwise.
+keyword argument values to take any order in the call.
 
 In declaration and calls, a keyword argument's name may not begin with
 @samp{!}, but references to it in the macro body do start with a
@@ -291,7 +288,13 @@ FREQUENCIES /VARIABLES=!vars.
 
 If a macro has both positional and keyword arguments, then the
 positional arguments must come first in the DEFINE command, and their
-values also come first in macro calls.
+values also come first in macro calls.  A keyword argument may be
+omitted by leaving its keyword out of the call, and a positional
+argument may be omitted by putting a command terminator where it would
+appear.  (The latter case also omits any following positional
+arguments and all keyword arguments, if there are any.)  When an
+argument is omitted, a default value is used: either the value
+specified in @code{!DEFAULT(@i{value})}, or an empty value otherwise.
 
 Each argument declaration specifies the form of its value:
 
@@ -575,6 +578,8 @@ Expands to a number token representing the number of characters in
 @deffn {Macro Function} !NULL
 Expands to an empty character sequence.
 
+@c Keep these examples in sync with the test for !NULL in
+@c tests/language/control/define.at:
 @example
 !NULL                        @expansion{} @r{empty}
 !QUOTE(!NULL)                @expansion{} ''
@@ -593,6 +598,8 @@ to the string's contents, with the quotes removed and any doubled
 quote marks reduced to singletons.  If the argument was not a quoted
 string, @code{!UNQUOTE} expands to the argument unchanged.
 
+@c Keep these examples in sync with the test for !QUOTE and !UNQUOTE in
+@c tests/language/control/define.at:
 @example
 !QUOTE(123.0)                @expansion{} '123.0'
 !QUOTE( 123 )                @expansion{} '123'