X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Fflow-control.texi;h=72d7a052cd4379bb9fb475c76530b669fcef1f9b;hb=f14ad7d1cee6228053fbadadfee9c86eb80da765;hp=d3235612b9fddb04ec0e42a1c697ae3e4afd0e17;hpb=72d12e896c52ce226c43dce80f683204e46e4f05;p=pspp diff --git a/doc/flow-control.texi b/doc/flow-control.texi index d3235612b9..72d7a052cd 100644 --- a/doc/flow-control.texi +++ b/doc/flow-control.texi @@ -45,6 +45,7 @@ BREAK. @vindex DEFINE @cindex macro +@node Macro Overview @subsection Overview @display @@ -53,20 +54,23 @@ BREAK. @t{!ENDDEFINE.} @end display +@noindent Each @i{argument} takes the following form: @display -@r{@{}@i{!arg_name} @t{=},@t{!POSITIONAL}@r{@}} +@r{@{}@i{!arg_name}@t{=} @math{|} @t{!POSITIONAL}@r{@}} @r{[}@t{!DEFAULT(}@i{default}@t{)}@r{]} @r{[}@t{!NOEXPAND}@r{]} -@r{@{}@t{!TOKENS(}@i{count}@t{)},@t{!CHAREND('}@i{token}@t{')},@t{!ENCLOSE('}@i{start}@t{','}@i{end}@t{')},@t{!CMDEND}@} +@r{@{}@t{!TOKENS(}@i{count}@t{)} @math{|} @t{!CHAREND('}@i{token}@t{')} @math{|} @t{!ENCLOSE('}@i{start}@t{' @math{|} '}@i{end}@t{')} @math{|} @t{!CMDEND}@} @end display +@noindent The following directives may be used within @i{body}: @example !OFFEXPAND !ONEXPAND @end example +@noindent The following functions may be used within the body: @display @t{!BLANKS(}@i{count}@t{)} @@ -83,6 +87,7 @@ The following functions may be used within the body: @t{!UPCASE(}@i{arg}@t{)} @end display +@noindent The body may also include the following constructs: @display @t{!IF (}@i{condition}@t{) !THEN} @i{true-expansion} @t{!ENDIF} @@ -98,6 +103,7 @@ The body may also include the following constructs: @t{!LET} @i{!var} @t{=} @i{expression} @end display +@node Macro Introduction @subsection Introduction The DEFINE command creates a @dfn{macro}, which is a name for a @@ -578,6 +584,8 @@ 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{} '' @@ -596,6 +604,8 @@ 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' @@ -998,11 +1008,9 @@ code block is executed. The condition is evaluated at the end of the loop, not at the beginning, so that the body of a loop with only a condition on @cmd{END LOOP} will always execute at least once. -If the index clause is not -present, then the loop is executed at most @var{max_loops} (@pxref{SET}) times -(but possibly fewer, if a condition clause evaluates to false or if -@cmd{BREAK} executes). -The default value of @var{max_loops} is 40. +If the index clause is not present, then the global @code{MXLOOPS} +setting, which defaults to 40, limits the number of iterations +(@pxref{SET MXLOOPS}). @cmd{BREAK} also terminates @cmd{LOOP} execution (@pxref{BREAK}).