Improve constructor

This commit introduces the "mangle" method, which can be implemented
by the caller in order to run any additional tree modifications after
a successful parse and commit (see the new testcase for an example).

* lib/Config/Parser.pm (new): Call the init method if lexicon
hash has been loaded.
(init,inited,commit): New methods.

* t/ConfigSpec3.pm: New file.
* t/TestConfig.pm: Don't attempt to load empty files.
* t/conf08.t: New file.

1 files changed, 21 insertions, 2 deletions

diff --git a/lib/Config/Parser.pm b/lib/Config/Parser.pm
index 843b70c..fed0100 100644
--- a/lib/Config/Parser.pm
+++ b/lib/Config/Parser.pm
@@ -12,6 +12,7 @@ our $VERSION = "1.00";
 sub new {
     my $class = shift;
     local %_ = @_;
+    my $loaded = 0;
 
     my @parseargs;
     if (my $filename = delete $_{filename}) {
@@ -31,6 +32,7 @@ sub new {
 #		print "LOADING FROM $c\n";
 		if (my $s = loadsynt($c)) {
 		    $_{lexicon} = { %{$_{lexicon}}, %$s };
+		    $loaded++;
 		}
 		last if $c eq $class;
 	    }
@@ -39,7 +41,7 @@ sub new {
     }
 
     my $self = $class->SUPER::new(%_);
-
+    $self->init if $loaded;
     if (@parseargs) {
 	$self->parse(@parseargs);
 	$self->commit or croak "configuration failed";
@@ -48,6 +50,22 @@ sub new {
     return $self;    
 }
 
+sub init {
+    my $self = shift;
+    $self->{_inited} = 1;
+}
+
+sub inited { shift->{_inited} };
+
+sub commit {
+    my $self = shift;
+    my $res = $self->SUPER::commit;
+    if ($res && $self->inited && $self->can('mangle')) {
+	$self->mangle;
+    }
+    return $res;
+}
+
 sub findsynt {
     my $class = shift;
     my $file = $class;
@@ -67,7 +85,8 @@ sub findsynt {
 sub loadsynt {
     my ($class) = @_;
     if (my ($file, $line, $data) = findsynt($class)) {
-	open(my $fh, '<', \$data);
+	open(my $fh, '<', \$data)
+	    or croak "can't open filehandle for data string";
 	my $d = $class->new(filename => $file,
 			    fh => $fh,
 			    line => $line,