0.41 spath_delta(): don't return full second path if it's a subset of…

… first one

Changes

@@ -1,5 +1,8 @@
 Revision history for Struct-Path
 
+0.41    2016-08-19
+        spath_delta(): don't return full second path if it's a subset of first one
+
 0.40    2016-08-18
         spath_delta() appeared
 

README.md

@@ -4,7 +4,7 @@ Struct::Path - Path for nested structures where path is also a structure
 
 # VERSION
 
-Version 0.40
+Version 0.41
 
 # SYNOPSIS
 
@@ -102,7 +102,7 @@ See [Struct::Path::PerlStyle](https://metacpan.org/pod/Struct::Path::PerlStyle)
 
 ## spath\_delta
 
-Returns delta for two passed paths.
+Returns delta for two passed paths. By delta means steps from the second path without beginning common steps for both.
 
     @delta = spath_delta($path1, $path2)
 

lib/Struct/Path.pm

@@ -14,11 +14,11 @@ Struct::Path - Path for nested structures where path is also a structure
 
 =head1 VERSION
 
-Version 0.40
+Version 0.41
 
 =cut
 
-our $VERSION = '0.40';
+our $VERSION = '0.41';
 
 =head1 SYNOPSIS
 
@@ -231,7 +231,7 @@ sub spath($$;@) {
 
 =head2 spath_delta
 
-Returns delta for two passed paths.
+Returns delta for two passed paths. By delta means steps from the second path without beginning common steps for both.
 
     @delta = spath_delta($path1, $path2)
 
@@ -241,12 +241,8 @@ sub spath_delta($$) {
     my ($frst, $scnd) = @_;
 
     croak "Second path must be an arrayref" unless (ref $scnd eq 'ARRAY');
-    if (defined $frst) {
-        croak "First path may be undef or an arrayref" unless (ref $frst eq 'ARRAY');
-        return @{$scnd} if (@{$scnd} < @{$frst});
-    } else {
-        return @{$scnd};
-    }
+    return @{$scnd} unless (defined $frst);
+    croak "First path may be undef or an arrayref" unless (ref $frst eq 'ARRAY');
 
     my $i = 0;
     MAIN: while ($i < @{$frst}) {

t/30-spath_delta.t

@@ -70,8 +70,8 @@ cmp_deeply(
 );
 cmp_deeply(
     \@delta,
-    [ {keys => ['a']},[0,3],{keys => ['ana', 'anb']} ],
-    "One step removed"
+    [],
+    "One step removed -- no delta"
 );
 
 @delta = spath_delta(