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http://git.sv.gnu.org/gitweb/?p=m4.git;a=commitdiff;h=8cf99d7ccdace1cddb3db6a127634afc6dcf06b5 The branch, master has been updated via 8cf99d7ccdace1cddb3db6a127634afc6dcf06b5 (commit) from 91b8f5afc665a8ba0cc2b0f06f371d4ae475809a (commit) Those revisions listed above that are new to this repository have not appeared on any other notification email; so we list those revisions in full, below. - Log ----------------------------------------------------------------- commit 8cf99d7ccdace1cddb3db6a127634afc6dcf06b5 Author: Eric Blake <[EMAIL PROTECTED]> Date: Wed Oct 31 08:50:30 2007 -0600 Test more corner cases. * tests/macros.at (Rescanning macros): Beef up test. * doc/m4.texinfo (Changecom): Beef up test. (Improved foreach): Document alternate foreachq style. * examples/foreachq3.m4: New file. * examples/loop.m4: New file. * Makefile.am (dist_pkgdata_DATA): Distribute them. Signed-off-by: Eric Blake <[EMAIL PROTECTED]> ----------------------------------------------------------------------- Summary of changes: ChangeLog | 10 ++++++ Makefile.am | 2 + doc/m4.texinfo | 78 ++++++++++++++++++++++++++++++++++++++++++++----- examples/foreachq3.m4 | 10 ++++++ examples/loop.m4 | 17 ++++++++++ tests/macros.at | 6 ++++ 6 files changed, 115 insertions(+), 8 deletions(-) create mode 100644 examples/foreachq3.m4 create mode 100644 examples/loop.m4 diff --git a/ChangeLog b/ChangeLog index a78c048..f953db2 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2007-10-31 Eric Blake <[EMAIL PROTECTED]> + + Test more corner cases. + * tests/macros.at (Rescanning macros): Beef up test. + * doc/m4.texinfo (Changecom): Beef up test. + (Improved foreach): Document alternate foreachq style. + * examples/foreachq3.m4: New file. + * examples/loop.m4: New file. + * Makefile.am (dist_pkgdata_DATA): Distribute them. + 2007-10-28 Eric Blake <[EMAIL PROTECTED]> More test coverage for autoconf usage patterns. diff --git a/Makefile.am b/Makefile.am index 22917a4..d9f107f 100644 --- a/Makefile.am +++ b/Makefile.am @@ -324,6 +324,7 @@ dist_pkgdata_DATA = \ examples/foreach2.m4 \ examples/foreachq.m4 \ examples/foreachq2.m4 \ + examples/foreachq3.m4 \ examples/forloop.m4 \ examples/forloop2.m4 \ examples/fstab.m4 \ @@ -332,6 +333,7 @@ dist_pkgdata_DATA = \ examples/incl.m4 \ examples/include.m4 \ examples/indir.m4 \ + examples/loop.m4 \ examples/misc.m4 \ examples/multiquotes.m4 \ examples/patsubst.m4 \ diff --git a/doc/m4.texinfo b/doc/m4.texinfo index 54884a3..4014344 100644 --- a/doc/m4.texinfo +++ b/doc/m4.texinfo @@ -4315,26 +4315,32 @@ implementations, it is a good idea to avoid @samp{(}, @samp{,}, and @samp{)} as the first character in @var{start}. @example -define(`echo', `$#:$@@:') +define(`echo', `$#:$*:$@@:') @result{} define(`hi', `HI') @result{} changecom(`(',`)') @result{} echo(hi) [EMAIL PROTECTED]::(hi) [EMAIL PROTECTED]:::(hi) changecom @result{} changecom(`((', `))') @result{} echo(hi) [EMAIL PROTECTED]:HI: [EMAIL PROTECTED]:HI:HI: echo((hi)) [EMAIL PROTECTED]::((hi)) [EMAIL PROTECTED]:::((hi)) changecom(`,', `)') @result{} echo(hi,hi)bye) [EMAIL PROTECTED]:HI,hi)bye: [EMAIL PROTECTED]:HI,hi)bye:HI,hi)bye: +changecom [EMAIL PROTECTED] +echo(hi,`,`'hi',hi) [EMAIL PROTECTED]:HI,,HI,HI:HI,,`'hi,HI: +echo(hi,`,`'hi',hi`'changecom(`,,', `hi')) [EMAIL PROTECTED]:HI,,`'hi,HI:HI,,`'hi,HI: @end example It is an error if the end of file occurs within a comment. @@ -8210,7 +8216,61 @@ Contrast the use of @[EMAIL PROTECTED], which quotes the first list element, with @[EMAIL PROTECTED] of the earlier implementation that returned the first list element directly. -For a different approach, the improved version of @code{foreach}, +The astute m4 programmer might notice that the solution above still uses +more memory, and thus more time, than strictly necessary. Note that [EMAIL PROTECTED], which contains an arbitrarily long quoted list, is expanded +and rescanned three times per iteration of @code{_foreachq}. +Furthermore, every iteration of the algorithm effectively unboxes then +reboxes the list, which costs a couple of macro invocations. It is +possible to rewrite the algorithm for a bit more speed by swapping the +order of the arguments to @code{_foreachq} in order to operate on an +unboxed list in the first place, and by using the fixed-length @samp{$#} +instead of an arbitrary length list as the key to end recursion. This +alternative approach is available as [EMAIL PROTECTED]@value{VERSION}/@/examples/@/foreach3.m4}: + [EMAIL PROTECTED] examples [EMAIL PROTECTED] +$ @kbd{m4 -I examples} +include(`foreachq3.m4') [EMAIL PROTECTED] +undivert(`foreachq3.m4')dnl [EMAIL PROTECTED](`-1') [EMAIL PROTECTED] foreachq(x, `item_1, item_2, ..., item_n', stmt) [EMAIL PROTECTED] quoted list, alternate improved version [EMAIL PROTECTED](`foreachq', [EMAIL PROTECTED](`$1')_$0(`$1', `$3'ifelse(`$2', `', `', [EMAIL PROTECTED] `, $2'))popdef(`$1')') [EMAIL PROTECTED](`_foreachq', `ifelse(`$#', `2', `', [EMAIL PROTECTED] `define(`$1', `$3')$2`'$0(`$1', `$2'ifelse(`$#', `3', `', [EMAIL PROTECTED] `, shift(shift(shift($@@)))'))')') [EMAIL PROTECTED]'dnl +traceon(`shift')debugmode(`aq') [EMAIL PROTECTED] +foreachq(`x', ``1', `2', `3', `4'', `x +')dnl [EMAIL PROTECTED] [EMAIL PROTECTED]: -4- shift(`x', `x [EMAIL PROTECTED]', `1', `2', `3', `4') [EMAIL PROTECTED]: -3- shift(`x [EMAIL PROTECTED]', `1', `2', `3', `4') [EMAIL PROTECTED]: -2- shift(`1', `2', `3', `4') [EMAIL PROTECTED] [EMAIL PROTECTED]: -4- shift(`x', `x [EMAIL PROTECTED]', `2', `3', `4') [EMAIL PROTECTED]: -3- shift(`x [EMAIL PROTECTED]', `2', `3', `4') [EMAIL PROTECTED]: -2- shift(`2', `3', `4') [EMAIL PROTECTED] [EMAIL PROTECTED]: -4- shift(`x', `x [EMAIL PROTECTED]', `3', `4') [EMAIL PROTECTED]: -3- shift(`x [EMAIL PROTECTED]', `3', `4') [EMAIL PROTECTED]: -2- shift(`3', `4') [EMAIL PROTECTED] [EMAIL PROTECTED] example + +For yet another approach, the improved version of @code{foreach}, available in @[EMAIL PROTECTED]/@/examples/@/foreach2.m4}, simply overquotes the arguments to @[EMAIL PROTECTED] to begin with, using @code{dquote_elt}. Then @[EMAIL PROTECTED] can just use @@ -8254,9 +8314,11 @@ In summary, recursion over list elements is trickier than it appeared at first glance, but provides a powerful idiom within @code{m4} processing. As a final demonstration, both list styles are now able to handle several scenarios that would wreak havoc on the original -implementations. This points out one other difference between the two +implementations. This points out one other difference between the list styles. @code{foreach} evaluates unquoted list elements only once, -in preparation for calling @[EMAIL PROTECTED] But @code{foreachq} +in preparation for calling @[EMAIL PROTECTED], similary for [EMAIL PROTECTED] as provided by @file{foreachq3.m4}. But [EMAIL PROTECTED], as provided by @file{foreachq2.m4}, evaluates unquoted list elements twice while visiting the first list element, once in @[EMAIL PROTECTED] and once in @[EMAIL PROTECTED] When deciding which list style to use, one must take into account whether diff --git a/examples/foreachq3.m4 b/examples/foreachq3.m4 new file mode 100644 index 0000000..beab455 --- /dev/null +++ b/examples/foreachq3.m4 @@ -0,0 +1,10 @@ +divert(`-1') +# foreachq(x, `item_1, item_2, ..., item_n', stmt) +# quoted list, alternate improved version +define(`foreachq', +`pushdef(`$1')_$0(`$1', `$3'ifelse(`$2', `', `', + `, $2'))popdef(`$1')') +define(`_foreachq', `ifelse(`$#', `2', `', + `define(`$1', `$3')$2`'$0(`$1', `$2'ifelse(`$#', `3', `', + `, shift(shift(shift($@)))'))')') +divert`'dnl diff --git a/examples/loop.m4 b/examples/loop.m4 new file mode 100644 index 0000000..31761c9 --- /dev/null +++ b/examples/loop.m4 @@ -0,0 +1,17 @@ +dnl Stress test for recursion algorithms. Usage: +dnl m4 -Ipath/to/examples [-Doptions] loop.m4 +dnl Options include: +dnl -Dalt - test with foreachq3 instead of foreachq2 +dnl -Dlimit=<num> - set upper limit of sequence to <num>, default 1000 +dnl -Dverbose - print the sequence to the screen, rather than discarding +dnl -Ddebug[=<code>] - execute <code> after forloop but before foreach +dnl -Dsleep=<num> - sleep for <num> seconds before exit, to allow time +dnl to examine peak process memory usage +include(`forloop2.m4')dnl +include(`quote.m4')dnl +include(ifdef(`alt', ``foreachq3.m4'', ``foreachq2.m4''))dnl +ifdef(`limit', `', `define(`limit', `1000')')dnl +ifdef(`verbose', `', `divert(`-1')')dnl +ifdef(`debug', `', `define(`debug')')dnl +foreachq(`i', dquote(1forloop(`i', `2', limit, `,i'))debug, ` i') +ifdef(`sleep',`syscmd(`echo done>/dev/tty;sleep 'sleep)')dnl diff --git a/tests/macros.at b/tests/macros.at index 3596baf..4c57bd0 100644 --- a/tests/macros.at +++ b/tests/macros.at @@ -538,9 +538,15 @@ AT_DATA([in], [[define(`echo', `$@')dnl len((echo(`01234567890123456789', `01234567890123456789')echo(`98765432109876543210', `98765432109876543210'))) +define(`argn', `$#')dnl +define(`echo1', [EMAIL PROTECTED]')define(`echo2', `,$@,')dnl +echo1(`1', `2', `3') argn(echo1(`1', `2', `3')) +echo2(`1', `2', `3') argn(echo2(`1', `2', `3')) ]]) AT_CHECK_M4([in], [0], [[84 +-1,2,3- 3 +,1,2,3, 5 ]]) AT_CLEANUP hooks/post-receive -- GNU M4 source repository
