- Added the Array and Hash .dig() method.

Example:
	say data.dig(:users, 0, :name);

is equivalent with:
	say data{:users}[0]{:name}

but it simply returns `nil` when it fails to `.fetch()` a given value from an object.

MANIFEST

@@ -611,6 +611,7 @@ scripts/Tests/count_in_factors.sf
 scripts/Tests/cpp_input_output.sf
 scripts/Tests/cramers_method.sf
 scripts/Tests/cross_and_zip_metaoperators.sf
+scripts/Tests/data_digging.sf
 scripts/Tests/data_handle.sf
 scripts/Tests/default_param_values.sf
 scripts/Tests/default_var_values.sf

lib/Sidef/Types/Array/Array.pm

@@ -533,6 +533,18 @@ package Sidef::Types::Array::Array {
         exists($self->[$index]) ? $self->[$index] : $default;
     }
 
+    sub dig {
+        my ($self, $key, @keys) = @_;
+
+        my $value = $self->fetch($key) // return;
+
+        foreach my $key (@keys) {
+            $value = $value->fetch($key) // return $value;
+        }
+
+        $value;
+    }
+
     sub _slice {
         my ($self, $from, $to) = @_;
 

lib/Sidef/Types/Hash/Hash.pm

@@ -49,6 +49,18 @@ package Sidef::Types::Hash::Hash {
         exists($self->{$key}) ? $self->{$key} : $default;
     }
 
+    sub dig {
+        my ($self, $key, @keys) = @_;
+
+        my $value = $self->fetch($key) // return;
+
+        foreach my $key (@keys) {
+            $value = $value->fetch($key) // return;
+        }
+
+        $value;
+    }
+
     sub slice {
         my ($self, @keys) = @_;
         $self->new(map { ($_ => exists($self->{$_}) ? $self->{$_} : undef) } @keys);

scripts/Tests/data_digging.sf

@@ -0,0 +1,29 @@
+#!/usr/bin/ruby
+
+var data = Hash(
+        lang => [
+            Hash(
+                name => "Sidef"
+            ),
+            Hash(
+                name => "Ruby",
+            ),
+            Hash(
+                name => "Perl",
+            )
+        ]
+)
+
+say data.dig(:lang, 0, :name);
+say data.dig(:lang, 1, :name);
+say data.dig(:lang, 2, :name);
+
+# Successful digging
+assert_eq(data.dig(:lang, 0, :name), "Sidef");
+assert_eq(data{:lang}.dig(-1, :name), "Perl");
+assert_eq(data{:lang}[1].dig(:name), "Ruby");
+
+# Fail digging
+assert_eq(data.dig(:lang, 42, :name), nil);
+assert_eq(data.dig(:hello, 0, :name), nil);
+assert_eq(data{:lang}.dig(42, :name), nil);