NAME
Devel::Chitin::OpTree - OpTree deparsing for Devel::Chitin
SYNOPSIS
my $optree = Devel::Chitin::OpTree->build_from_location($subref);
# or
$optree = Devel::Chitin::OpTree->build_from_location($location_obj);
$optree->walk_inorder(sub {
my $op = shift;
my $b_op = $op->op;
printf("OP named %s has %d children\n",
$b_op->name, scalar(@{ $op->children }));
printf(" parent %s, sibling %s, next %s\n",
$op->parent->op->name,
$op->sibling->op->name,
$op->next->op->name);
});
print $optree->deparse;
DESCRIPTION
This class is a wrapper around the B::OP-related classes to make navigating around the optree and deparsing easier. It differs from B::Deparse in that Devel::Chitin::OpTree is meant to be used at run-time and it supports deparsing from any point in the tree, not just at function entry points.
This module contains a mixture of methods responsible for construction, helpers used by the other OpTree-related classes, and deparsing methods for nullary OPs.
Constructor
Constructing an OpTree for a subroutine is done via build_from_location()
my $optree = Devel::Chitin::OpTree->build_from_location($subref);
$optree = Devel::Chitin::OpTree->build_from_location($location_obj);
You can pass in either a subref or a Devel::Chitin::Location object. In the latter case, it uses the object's package
and subroutine
values to find the sub. Note that locations within anonymous subs aren't supported yet.
The returned OpTree object is the root of the optree. Each element of the tree is itself a Devel::Chitin::OpTree instance. You can explore the tree with the methods below.
OpTrees are cached, so that if build_from_location()
is called twice for the same subroutine, the same OpTree object will be returned.
Methods
- op
-
Returns the B::OP-related object wrapped by the invocant
- parent
-
Returns a Devel::Chitin::OpTree instance for the parent node of the invocant
- next
-
Returns a Devel::Chitin::OpTree instance for the invocant's OP's next pointer
- sibling
-
Returns a Devel::Chitin::OpTree instance for the invocant's OP's sibling pointer
- children
-
Returns a listref of Devel::Chitin::OpTree objects representing the children of the invocant
- cv
-
Returns a
B::CV|B/B::CV-Methods
object for the subroutine the invocant is a part of - root_op
-
Returns a Devel::Chitin::OpTree instance representing the entrypoint for the subroutine the invocant is a part of
- walk_inorder
-
$op->walk_inorder($cb);
Perform an in-order walk of the optree and call the given callback function (a coderef) for each node in the tree. The callback is passed a Devel::Chitin::OpTree object as its only argument.
- walk_preorder
-
$op->walk_preorder($cb);
Perform a pre-order (children before parent) walk of the optree and call the given callback function (a coderef) for each node in the tree. The callback is passed a Devel::Chitin::OpTree object as its only argument.
- deparse
-
Returns a string containing Perl code by essentially doing an in-order walk of the tree, turning each op into the Perl code it represents.
- pp_*
-
These functions a responsible for the deparsing process. They contain whatever logic is necessary to turn the node and its children into Perl.
SEE ALSO
Devel::Chitin, Devel::Chitin::Location, B, B::Deparse, B::DeparseTree
AUTHOR
Anthony Brummett <brummett@cpan.org>
COPYRIGHT
Copyright 2016, Anthony Brummett. This module is free software. It may be used, redistributed and/or modified under the same terms as Perl itself.