!BLANKS and !CONCAT pass basic tests.

[pspp] / doc / flow-control.texi

diff --git a/doc/flow-control.texi b/doc/flow-control.texi
index 77b4a3c42e350de55dbff86d2bc8876f06d6b83c..7a95758a78b92cb4936dedc6d9b43e70395df59d 100644 (file)
--- a/doc/flow-control.texi
+++ b/doc/flow-control.texi
@@ -338,6 +338,8 @@ are equivalent; for a quoted string of spaces, use
 In the examples below, @samp{_} stands in for a space to make the
 results visible.
 
+@c Keep these examples in sync with the test for !BLANKS in
+@c tests/language/control/define.at:
 @example
 !BLANKS(0)                  @expansion{} @r{empty}
 !BLANKS(1)                  @expansion{} _
@@ -351,6 +353,8 @@ Expands to the concatenation of all of the arguments.  Before
 concatenation, each quoted string argument is unquoted, as if
 @code{!UNQUOTE} were applied.
 
+@c Keep these examples in sync with the test for !CONCAT in
+@c tests/language/control/define.at:
 @example
 !CONCAT(x, y)                @expansion{} xy
 !CONCAT('x', 'y')            @expansion{} xy
@@ -512,9 +516,26 @@ to uppercase.
 @node Macro Settings
 @subsection Macro Settings
 
-MPRINT
-MEXPAND
-MNEST
+Some macro behavior is controlled through the SET command
+(@pxref{SET}).  This section describes these settings.
+
+Any SET command that changes these settings within a macro body only
+takes effect following the macro.  This is because PSPP expands a
+macro's entire body at once, so that the SET command inside the body
+only executes afterwards.
+
+The MEXPAND setting (@pxref{SET MEXPAND}) controls whether macros will
+be expanded at all.  By default, macro expansion is on.  To avoid
+expansion of macros called within a macro body, use @code{!OFFEXPAND}
+and @code{!ONEXPAND} (@pxref{Controlling Macro Expansion}).
+
+When MPRINT (@pxref{SET MPRINT}) is turned on, PSPP logs an expansion
+of each macro in the input.  This feature can be useful for debugging
+macro definitions.
+
+MNEST (@pxref{SET MNEST}) limits the depth of expansion of macro
+calls, that is, the nesting level of macro expansion.
+
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