CVf_METHOD CVf_LOCKED CVf_LVALUE
PMf_KEEP PMf_GLOBAL PMf_CONTINUE PMf_EVAL PMf_ONCE
PMf_MULTILINE PMf_SINGLELINE PMf_FOLD PMf_EXTENDED);
-$VERSION = 0.591;
+$VERSION = 0.60;
use strict;
# Changes between 0.50 and 0.51:
# - added support for Chip's OP_METHOD_NAMED
# - added support for Ilya's OPpTARGET_MY optimization
# - elided arrows before `()' subscripts when possible
+# Changes between 0.59 and 0.60
+# - support for method attribues was added
+# - some warnings fixed
+# - separate recognition of constant subs
+# - rewrote continue block handling, now recoginizing for loops
+# - added more control of expanding control structures
# Todo:
# - finish tr/// changes
# - left/right context
# - recognize `use utf8', `use integer', etc
# - treat top-level block specially for incremental output
-# - interpret in high bit chars in string as utf8 \x{...} (when?)
-# - copy comments (look at real text with $^P?)
+# - interpret high bit chars in string as utf8 \x{...} (when?)
+# - copy comments (look at real text with $^P?)
# - avoid semis in one-statement blocks
# - associativity of &&=, ||=, ?:
# - ',' => '=>' (auto-unquote?)
# - version using op_next instead of op_first/sibling?
# - avoid string copies (pass arrays, one big join?)
# - auto-apply `-u'?
-# - while{} with one-statement continue => for(; XXX; XXX) {}?
# - -uPackage:: descend recursively?
# - here-docs?
# - <DATA>?
$self->{'unquote'} = 1;
} elsif (substr($arg, 0, 2) eq "-s") {
$self->style_opts(substr $arg, 2);
+ } elsif ($arg =~ /^-x(\d)$/) {
+ $self->{'expand'} = $1;
}
}
return $self;
my $self = shift;
my($op, $cx) = @_;
# cluck if class($op) eq "NULL";
+# cluck unless $op;
# return $self->$ {\("pp_" . $op->name)}($op, $cx);
my $meth = "pp_" . $op->name;
return $self->$meth($op, $cx);
return "XXX";
}
-# leave and scope/lineseq should probably share code
-sub pp_leave {
+sub lineseq {
my $self = shift;
- my($op, $cx) = @_;
- my ($kid, $expr);
- my @exprs;
- local($self->{'curstash'}) = $self->{'curstash'};
- $kid = $op->first->sibling; # skip enter
- if (is_miniwhile($kid)) {
- my $top = $kid->first;
- my $name = $top->name;
- if ($name eq "and") {
- $name = "while";
- } elsif ($name eq "or") {
- $name = "until";
- } else { # no conditional -> while 1 or until 0
- return $self->deparse($top->first, 1) . " while 1";
- }
- my $cond = $top->first;
- my $body = $cond->sibling->first; # skip lineseq
- $cond = $self->deparse($cond, 1);
- $body = $self->deparse($body, 1);
- return "$body $name $cond";
- }
- for (; !null($kid); $kid = $kid->sibling) {
+ my(@ops) = @_;
+ my($expr, @exprs);
+ for (my $i = 0; $i < @ops; $i++) {
$expr = "";
- if (is_state $kid) {
- $expr = $self->deparse($kid, 0);
- $kid = $kid->sibling;
- last if null $kid;
+ if (is_state $ops[$i]) {
+ $expr = $self->deparse($ops[$i], 0);
+ $i++;
+ last if $i > $#ops;
+ }
+ if (!is_state $ops[$i] and $ops[$i+1] and !null($ops[$i+1]) and
+ $ops[$i+1]->name eq "leaveloop" and $self->{'expand'} < 3)
+ {
+ push @exprs, $expr . $self->for_loop($ops[$i], 0);
+ $i++;
+ next;
}
- $expr .= $self->deparse($kid, 0);
+ $expr .= $self->deparse($ops[$i], 0);
push @exprs, $expr if length $expr;
}
- if ($cx > 0) { # inside an expression
- return "do { " . join(";\n", @exprs) . " }";
- } else {
- return join(";\n", @exprs) . ";";
- }
+ return join(";\n", @exprs);
}
-sub pp_scope {
- my $self = shift;
- my($op, $cx) = @_;
- my ($kid, $expr);
- my @exprs;
- for ($kid = $op->first; !null($kid); $kid = $kid->sibling) {
- $expr = "";
- if (is_state $kid) {
- $expr = $self->deparse($kid, 0);
- $kid = $kid->sibling;
- last if null $kid;
+sub scopeop {
+ my($real_block, $self, $op, $cx) = @_;
+ my $kid;
+ my @kids;
+ local($self->{'curstash'}) = $self->{'curstash'} if $real_block;
+ if ($real_block) {
+ $kid = $op->first->sibling; # skip enter
+ if (is_miniwhile($kid)) {
+ my $top = $kid->first;
+ my $name = $top->name;
+ if ($name eq "and") {
+ $name = "while";
+ } elsif ($name eq "or") {
+ $name = "until";
+ } else { # no conditional -> while 1 or until 0
+ return $self->deparse($top->first, 1) . " while 1";
+ }
+ my $cond = $top->first;
+ my $body = $cond->sibling->first; # skip lineseq
+ $cond = $self->deparse($cond, 1);
+ $body = $self->deparse($body, 1);
+ return "$body $name $cond";
}
- $expr .= $self->deparse($kid, 0);
- push @exprs, $expr if length $expr;
+ } else {
+ $kid = $op->first;
+ }
+ for (; !null($kid); $kid = $kid->sibling) {
+ push @kids, $kid;
}
if ($cx > 0) { # inside an expression, (a do {} while for lineseq)
- return "do { " . join(";\n", @exprs) . " }";
+ return "do { " . $self->lineseq(@kids) . " }";
} else {
- return join(";\n", @exprs) . ";";
+ return $self->lineseq(@kids) . ";";
}
}
-sub pp_lineseq { pp_scope(@_) }
+sub pp_scope { scopeop(0, @_); }
+sub pp_lineseq { scopeop(0, @_); }
+sub pp_leave { scopeop(1, @_); }
# The BEGIN {} is used here because otherwise this code isn't executed
# when you run B::Deparse on itself.
my ($op, $cx, $lowop, $lowprec, $highop, $highprec, $blockname) = @_;
my $left = $op->first;
my $right = $op->first->sibling;
- if ($cx == 0 and is_scope($right) and $blockname) { # if ($a) {$b}
+ if ($cx == 0 and is_scope($right) and $blockname
+ and $self->{'expand'} < 7)
+ { # if ($a) {$b}
$left = $self->deparse($left, 1);
$right = $self->deparse($right, 0);
return "$blockname ($left) {\n\t$right\n\b}\cK";
- } elsif ($cx == 0 and $blockname and not $self->{'parens'}) { # $b if $a
+ } elsif ($cx == 0 and $blockname and not $self->{'parens'}
+ and $self->{'expand'} < 7) { # $b if $a
$right = $self->deparse($right, 1);
$left = $self->deparse($left, 1);
return "$right $blockname $left";
my $false = $true->sibling;
my $cuddle = $self->{'cuddle'};
unless ($cx == 0 and (is_scope($true) and $true->name ne "null") and
- (is_scope($false) || is_ifelse_cont($false))) {
+ (is_scope($false) || is_ifelse_cont($false))
+ and $self->{'expand'} < 7) {
$cond = $self->deparse($cond, 8);
$true = $self->deparse($true, 8);
$false = $self->deparse($false, 8);
return $head . join($cuddle, "", @elsifs) . $false;
}
-sub pp_leaveloop {
+sub loop_common {
my $self = shift;
- my($op, $cx) = @_;
+ my($op, $cx, $init) = @_;
my $enter = $op->first;
my $kid = $enter->sibling;
local($self->{'curstash'}) = $self->{'curstash'};
my $head = "";
my $bare = 0;
+ my $body;
+ my $cond = undef;
if ($kid->name eq "lineseq") { # bare or infinite loop
if (is_state $kid->last) { # infinite
$head = "for (;;) "; # shorter than while (1)
+ $cond = "";
} else {
$bare = 1;
}
+ $body = $kid;
} elsif ($enter->name eq "enteriter") { # foreach
my $ary = $enter->first->sibling; # first was pushmark
my $var = $ary->sibling;
$var = "\$" . $self->deparse($var, 1);
}
$head = "foreach $var ($ary) ";
- $kid = $kid->first->first->sibling; # skip OP_AND and OP_ITER
+ $body = $kid->first->first->sibling; # skip OP_AND and OP_ITER
} elsif ($kid->name eq "null") { # while/until
$kid = $kid->first;
- my $name = {"and" => "while", "or" => "until"}
- ->{$kid->name};
- $head = "$name (" . $self->deparse($kid->first, 1) . ") ";
- $kid = $kid->first->sibling;
+ my $name = {"and" => "while", "or" => "until"}->{$kid->name};
+ $cond = $self->deparse($kid->first, 1);
+ $head = "$name ($cond) ";
+ $body = $kid->first->sibling;
} elsif ($kid->name eq "stub") { # bare and empty
return "{;}"; # {} could be a hashref
}
- # The third-to-last kid is the continue block if the pointer used
- # by `next BLOCK' points to its first OP, which happens to be the
- # the op_next of the head of the _previous_ statement.
- # Unless it's a bare loop, in which case it's last, since there's
- # no unstack or extra nextstate.
- # Except if the previous head isn't null but the first kid is
- # (because it's a nulled out nextstate in a scope), in which
- # case the head's next is advanced past the null but the nextop's
- # isn't, so we need to try nextop->next.
- my $precont;
- my $cont = $kid->first;
- if ($bare) {
- while (!null($cont->sibling)) {
- $precont = $cont;
- $cont = $cont->sibling;
- }
- } else {
- while (!null($cont->sibling->sibling->sibling)) {
- $precont = $cont;
- $cont = $cont->sibling;
+ # If there isn't a continue block, then the next pointer for the loop
+ # will point to the unstack, which is kid's penultimate child, except
+ # in a bare loop, when it will point to the leaveloop. When neither of
+ # these conditions hold, then the third-to-last child in the continue
+ # block (or the last in a bare loop).
+ my $cont_start = $enter->nextop;
+ my $cont;
+ if ($$cont_start != $$op and $ {$cont_start->sibling} != $ {$body->last}) {
+ if ($bare) {
+ $cont = $body->last;
+ } else {
+ $cont = $body->first;
+ while (!null($cont->sibling->sibling->sibling)) {
+ $cont = $cont->sibling;
+ }
+ }
+ my $state = $body->first;
+ my $cuddle = $self->{'cuddle'};
+ my @states;
+ for (; $$state != $$cont; $state = $state->sibling) {
+ push @states, $state;
+ }
+ $body = $self->lineseq(@states);
+ if (defined $cond and not is_scope $cont and $self->{'expand'} < 3) {
+ $head = "for ($init; $cond; " . $self->deparse($cont, 1) .") ";
+ $cont = "\cK";
+ } else {
+ $cont = $cuddle . "continue {\n\t" .
+ $self->deparse($cont, 0) . "\n\b}\cK";
}
- }
- if ($precont and $ {$precont->next} == $ {$enter->nextop}
- || $ {$precont->next} == $ {$enter->nextop->next} )
- {
- my $state = $kid->first;
- my $cuddle = $self->{'cuddle'};
- my($expr, @exprs);
- for (; $$state != $$cont and can $state "sibling"; $state = $state->sibling) {
- $expr = "";
- if (is_state $state) {
- $expr = $self->deparse($state, 0);
- $state = $state->sibling;
- last if null $state;
- }
- $expr .= $self->deparse($state, 0);
- push @exprs, $expr if $expr;
- }
- $kid = join(";\n", @exprs);
- if (class($cont) eq "LISTOP") {
- $cont = $cuddle . "continue {\n\t" .
- $self->deparse($cont, 0) . "\n\b}\cK";
- } else {
- $cont = "\cK";
- }
} else {
$cont = "\cK";
- $kid = $self->deparse($kid, 0);
+ $body = $self->deparse($body, 0);
}
- return $head . "{\n\t" . $kid . "\n\b}" . $cont;
+ return $head . "{\n\t" . $body . "\n\b}" . $cont;
+}
+
+sub pp_leaveloop { loop_common(@_, "") }
+
+sub for_loop {
+ my $self = shift;
+ my($op, $cx) = @_;
+ my $init = $self->deparse($op, 1);
+ return $self->loop_common($op->sibling, $cx, $init);
}
sub pp_leavetry {
=back
+=item B<-x>I<LEVEL>
+
+Expand conventional syntax constructions into equivalent ones that expose
+their internal operation. I<LEVEL> should be a digit, with higher values
+meaning more expansion. As with B<-q>, this actually involves turning off
+special cases in B::Deparse's normal operations.
+
+If I<LEVEL> is at least 3, for loops will be translated into equivalent
+while loops with a continue block; for instance
+
+ for ($i = 0; $i < 10; ++$i) {
+ print $i;
+ }
+
+turns into
+
+ $i = 0;
+ while ($i < 10) {
+ print $i;
+ } continue {
+ ++$i
+ }
+
+Note that in a few cases this translation can't be perfectly carried back
+into the source code -- if the loop'd initializer declares a my variable,
+for instance, it won't have the correct scope outside of the loop.
+
+If I<LEVEL> is at least 7, if statements will be translated into equivalent
+expressions using C<&&>, C<?:> and C<do {}>; for instance
+
+ print 'hi' if $nice;
+ if ($nice) {
+ print 'hi';
+ }
+ if ($nice) {
+ print 'hi';
+ } else {
+ print 'bye';
+ }
+
+turns into
+
+ $nice and print 'hi';
+ $nice and do { print 'hi' };
+ $nice ? do { print 'hi' } : do { print 'bye' };
+
+Long sequences of elsifs will turn into nested ternary operators, which
+B::Deparse doesn't know how to indent nicely.
+
=back
=head1 USING B::Deparse AS A MODULE
=head1 AUTHOR
-Stephen McCamant <smccam@uclink4.berkeley.edu>, based on an earlier
+Stephen McCamant <smcc@CSUA.Berkeley.EDU>, based on an earlier
version by Malcolm Beattie <mbeattie@sable.ox.ac.uk>, with
contributions from Gisle Aas, James Duncan, Albert Dvornik, Hugo van
der Sanden, Gurusamy Sarathy, and Nick Ing-Simmons.
projects / p5sagit/p5-mst-13.2.git / commitdiff