Code and test updates

Code changes (in package order):
- Data::Hopen::hnew(): provide more accurate error messages.
- Data::Hopen::loadfrom(): no longer require a list of stems.
- Data::Hopen::G::DAG: pass the node inputs to visit_{node,goal}; change
  some exception text
- Data::Hopen::G::Entity: custom stringification for easier debugging
- Added Data::Hopen::G::NoOp

- !!! >>> Data::Hopen::Scope: when merging predecessor-node outputs
  into successor-node inputs, DO NOT CLONE.  This way blessed references
  can be successfully passed between nodes. <<< !!!

- Data::Hopen::Util::NameSet: Tweaked code so 100% coverage
  is achievable.
- Added Data::Hopen::Visitor
- Updated documentation

Test changes:
- Added t/lib/PackagesInThisFile, which is a crazy way of doing
  subtests, each in its own package.

WIP: a way to merge hashes, cloning non-blessed references but not
     references.

Changes

@@ -1,5 +1,8 @@
 Revision history for Data-Hopen
 
+0.000013    2019-05-26
+        Functional changes throughout
+
 0.000012    2019-02-28
         No changes - stable release of 0.000011
 

MANIFEST

@@ -10,6 +10,7 @@ lib/Data/Hopen/G/Goal.pm
 lib/Data/Hopen/G/GraphBuilder.pm
 lib/Data/Hopen/G/Link.pm
 lib/Data/Hopen/G/Node.pm
+lib/Data/Hopen/G/NoOp.pm
 lib/Data/Hopen/G/Op.pm
 lib/Data/Hopen/G/OutputOp.pm
 lib/Data/Hopen/G/Runnable.pm
@@ -22,6 +23,7 @@ lib/Data/Hopen/Scope/Overrides.pm
 lib/Data/Hopen/Util/Data.pm
 lib/Data/Hopen/Util/Filename.pm
 lib/Data/Hopen/Util/NameSet.pm
+lib/Data/Hopen/Visitor.pm
 LICENSE.md
 Makefile.PL
 MANIFEST			This list of files
@@ -34,24 +36,27 @@ t/001-entity.t
 t/002-link.t
 t/003-node.t
 t/004-goal.t
-t/005-op.t
-t/006-collect-op.t
 t/007-hnew.t
 t/008-nameset.t
 t/009-hopen-constants.t
 t/010-scope-hash.t
 t/011-scope-env.t
 t/012-scope-nested.t
-t/020-dag.t
-t/021-dag-single-goal.t
-t/022-dag-visitor.t
-t/023-dag-warnings.t
-t/024-dag-merge-node-inputs.t
 t/030-ordered_pred.t
+t/100-op.t
+t/101-collect-op.t
+t/120-dag.t
+t/121-dag-single-goal.t
+t/122-dag-visitor.t
+t/123-dag-warnings.t
+t/124-dag-merge-node-inputs.t
+t/998-sig-die.t
+t/999-extras-for-coverage.t
 t/dir200/inner.hopen.pl
 t/dir200/inner/.hopen.pl
 t/dir200/inner/z.hopen.pl
 t/lib/HopenTest.pm
+t/lib/PackagesInThisFile.pm
 xt/boilerplate.t
 xt/manifest.t
 xt/pod-coverage.t

MANIFEST.SKIP

@@ -1,3 +1,7 @@
+# WIP files
+^lib.Data.Hopen.Util.MergeWithoutCloneBlessed\.pm
+^t.005-merge-without-clone-blessed\.NOTYET
+
 # Miscellaneous
 ^\.editorconfig
 ^\.[^\\\/]*\.yml

Makefile.PL

@@ -173,13 +173,18 @@ my %opts = (
         'Pod::Text' => '0',         # pod2text
     },
     TEST_REQUIRES => {
+        'Capture::Tiny' => '0',
         'Carp' => '0',
         'Exporter' => '0',
         'Import::Into' => '0',
+        'List::AutoNumbered' => '0.000006',
+        'Quote::Code' => '1.0102',
         'rlib' => '0',
         'Scalar::Util' => '0',
-        'Test::Deep' => '0.084',        # for superhashof
+        'Sub::Identify' => '0.14',
+        'Test::Deep' => '0.098',        # for superhashof, Test::Deep::NoTest
         ## 'Test::Directory' => '0.02',    # for subdirs
+        'Test::Fatal' => '0.014',
         'Test::More' => '0',
         # Test::TempDir::Tiny?  If so, remove Test::Directory dependency?
         'Test::Warn' => '0.35',     # for metadata
@@ -188,6 +193,7 @@ my %opts = (
         #'Algorithm::Dependency' => '1.106',
             # - Probably don't need this; we can use Graph::topological_sort().
 
+        #'base' => '0',                  # as used by Hash::Merge
         'Carp' => '0',
 
         'Class::Method::Modifiers' => '2.10',   # most recent code change
@@ -200,6 +206,7 @@ my %opts = (
 
 
         ## 'Class::XPath' => '1.4',
+        #'Clone::Choose' => '0.008',     # as used by Hash::Merge
         'Config' => '0',
         #'Cwd' => '0',
 

lib/Data/Hopen.pm

@@ -24,7 +24,7 @@ use Data::Hopen::Util::NameSet;
 use Getargs::Mixed;
 use Storable ();
 
-our $VERSION = '0.000013'; # TRIAL
+our $VERSION = '0.000013';
 
 # Docs {{{1
 
@@ -97,11 +97,27 @@ is the same as
 
     Data::Hopen::G::DAG->new( name => 'foo' );
 
-If the provided name does not include a double-colon, it is first tried after
-C<Data::Hopen::G::>.  It is then tried in C<Data::Hopen::> and as a
-complete package name.  The first one that succeeds is used.
+The first parameter (C<$class>) is an abbreviated package name.  It is tried
+as the following, in order.  The first one that succeeds is used.
 
-The first parameter must be a part of a class name, and the second parameter
+=over
+
+=item 1.
+
+C<Data::Hopen::G::$class>.  This is tried only if C<$class>
+does not include a double-colon.
+
+=item 2.
+
+C<Data::Hopen::$class>
+
+=item 3.
+
+C<$class>
+
+=back
+
+The second parameter
 must be the name of the new instance.  All other parameters are passed
 unchanged to the relevant constructor.
 
@@ -112,16 +128,22 @@ sub hnew {
     my @stems = ('Data::Hopen::G::', 'Data::Hopen::', '');
     shift @stems if $class =~ /::/;
 
+    my $found_class = false;
+
     foreach my $stem (@stems) {
-        my $instance = eval {
-            eval "require $stem$class";
-            "$stem$class"->new('name', @_)
-                # put 'name' in front of the name parameter.
-        };
+        eval "require $stem$class";
+        next if $@;
+        $found_class = "$stem$class";
+        my $instance = "$found_class"->new('name', @_);
+            # put 'name' in front of the name parameter.
         return $instance if $instance;
     }
 
-    croak "Could not find class for $class";
+    if($found_class) {
+        croak "Could not create instance for $found_class";
+    } else {
+        croak "Could not find class for $class";
+    }
 } #hnew()
 
 =head2 loadfrom
@@ -131,13 +153,14 @@ sub hnew {
     my $fullname = loadfrom($name[, @stems]);
 
 Returns the full name of the loaded package, or falsy on failure.
+If C<@stems> is omitted, no stem is used, i.e., C<$name> is tried as-is.
 
 =cut
 
 sub loadfrom {
     my $class = shift or croak 'Need a class';
 
-    foreach my $stem (@_) {
+    foreach my $stem (@_, '') {
         eval "require $stem$class";
         return "$stem$class" unless $@;
     }
@@ -157,10 +180,15 @@ Each line is prefixed with C<'# '> for the benefit of test runs.
 The list is in C<{}> so that it won't be evaluated if logging is turned off.
 It is a full block, so you can run arbitrary code to decide what to log.
 If the block returns an empty list, hlog will not produce any output.
+However, if the block returns at least one element, hlog will produce at
+least a C<'# '>.
 
 The message will be output only if L</$VERBOSE> is at least the given minimum
 verbosity level (1 by default).
 
+If C<< $VERBOSE > 2 >>, the filename and line from which hlog was called
+will also be printed.
+
 =cut
 
 sub hlog (&;$) {
@@ -172,7 +200,12 @@ sub hlog (&;$) {
 
     chomp $log[$#log] if $log[$#log];
     # TODO add an option to number the lines of the output
-    say STDERR (join(' ', @log)) =~ s/^/# /gmr;
+    my $msg = (join(' ', @log)) =~ s/^/# /gmr;
+    if($VERBOSE>2) {
+        my ($package, $filename, $line) = caller;
+        $msg .= " (at $filename:$line)";
+    }
+    say STDERR $msg;
 } #hlog()
 
 =head2 isMYH

lib/Data/Hopen/Base.pm

@@ -8,7 +8,7 @@ package Data::Hopen::Base;
 use parent 'Exporter';
 use Import::Into;
 
-our $VERSION = '0.000013'; # TRIAL
+our $VERSION = '0.000013';
 
 # Pragmas
 use 5.014;
@@ -36,7 +36,9 @@ our @EXPORT = qw(true false);
 
 #DEBUG
 BEGIN {
-    $SIG{'__DIE__'} = sub { Carp::confess(@_) } unless $SIG{'__DIE__'};
+    unless($SIG{'__DIE__'}) {
+        $SIG{'__DIE__'} = sub { Carp::confess(@_) };
+    }
     #$Exporter::Verbose=1;
 }
 

lib/Data/Hopen/G.pod

@@ -45,4 +45,9 @@ edges is expressed in a DAG.  A DAG has zero or more goals
 (L<Data::Hopen::G::Goal>) that represent named activities expressed
 in the DAG.
 
+=head1 VISITORS
+
+L<Data::Hopen::G::DAG/run> can take a C<visitor> parameter.  The visitor
+should be an instance of a concrete subclass of L<Data::Hopen::Visitor>.
+
 =cut

lib/Data/Hopen/G/CollectOp.pm

@@ -2,7 +2,7 @@
 package Data::Hopen::G::CollectOp;
 use Data::Hopen::Base;
 
-our $VERSION = '0.000013'; # TRIAL
+our $VERSION = '0.000013';
 
 use parent 'Data::Hopen::G::Op';
 use Class::Tiny {
@@ -17,7 +17,7 @@ use Storable ();
 
 =head1 NAME
 
-Data::Hopen::G::CollectOp - a no-op
+Data::Hopen::G::CollectOp - a passthrough operation
 
 =head1 SYNOPSIS
 

lib/Data/Hopen/G/DAG.pm

@@ -2,7 +2,7 @@
 package Data::Hopen::G::DAG;
 use Data::Hopen::Base;
 
-our $VERSION = '0.000013'; # TRIAL
+our $VERSION = '0.000013';
 
 use parent 'Data::Hopen::G::Op';
 use Class::Tiny {
@@ -34,7 +34,9 @@ use Data::Hopen::G::Node;
 use Data::Hopen::G::CollectOp;
 use Data::Hopen::Util::Data qw(forward_opts);
 use Data::Hopen::OrderedPredecessorGraph;
+use Getargs::Mixed; # parameters, which doesn't permit undef
 use Hash::Merge;
+use Scalar::Util qw(refaddr);
 use Storable ();
 
 # Class data {{{1
@@ -157,9 +159,9 @@ sub _run {
     # Remove _final from the order for now - I don't yet know what it means
     # to traverse _final.
     warn "Last item in order isn't _final!  This might indicate a bug in hopen, or that some graph edges are missing."
-        unless $QUIET or $order[$#order] == $self->_final;
+        unless $QUIET or refaddr $order[$#order] == refaddr $self->_final;
 
-    @order = grep { $_ != $self->_final } @order;
+    @order = grep { refaddr $_ != refaddr $self->_final } @order;
 
     # --- Check for non-connected ops, and goals with no inputs ---
 
@@ -228,6 +230,7 @@ sub _run {
                 hlog { '  -- no links' };
                 $node_inputs->merge(%{$pred->outputs});
                     # TODO specify which set these are.
+                    # Use the predecessor's identity as the set.
                 next;
             }
 
@@ -237,6 +240,7 @@ sub _run {
             my $link_inputs = Data::Hopen::Scope::Hash->new->put(%{$hrPredOutputs});
                 # All links get the same outer scope --- they are parallel,
                 # not in series.
+                # TODO use the predecessor's identity as the set.
             $link_inputs->outer($self->scope);
                 # The links run at the same scope level as the node.
             $link_inputs->local(true);
@@ -265,14 +269,14 @@ sub _run {
 
         # Give the visitor a chance, and stash the results if necessary.
         if(eval { $node->DOES('Data::Hopen::G::Goal') }) {
-            $args{visitor}->visit_goal($node) if $args{visitor};
+            $args{visitor}->visit_goal($node, $node_inputs) if $args{visitor};
 
             # Save the result if there is one.  Don't save {}.
             # use $node->outputs, not $step_output, since the visitor may
             # alter $node->outputs.
             $retval->{$node->name} = $node->outputs if keys %{$node->outputs};
         } else {
-            $args{visitor}->visit_node($node) if $args{visitor};
+            $args{visitor}->visit_node($node, $node_inputs) if $args{visitor};
         }
 
     } #foreach node in topo-sort order
@@ -384,10 +388,9 @@ Returns the node, for the sake of chaining.
 =cut
 
 sub add {
-    my $self = shift or croak 'Need an instance';
-    my $node = shift or croak 'Need a node';
+    my ($self, undef, $node) = parameters('self', ['node'], @_);
     return if $self->_graph->has_vertex($node);
-    hlog { __PACKAGE__, 'adding', Dumper($node) } 2;
+    hlog { __PACKAGE__, $self->name, 'adding', Dumper($node) } 2;
 
     $self->_graph->add_vertex($node);
     #$self->_node_by_name->{$node->name} = $node if $node->name;