From 89a8f665f70644989adf70cd132bf0f38ef3414d Mon Sep 17 00:00:00 2001
From: Syphax Bouazzouni <gs_bouazzouni@esi.dz>
Date: Tue, 28 Dec 2021 16:54:30 +0100
Subject: [PATCH] fix #4 ; add regex filter

---
 lib/goo/base/filter.rb    | 22 +++++++++++++---------
 lib/goo/sparql/queries.rb | 25 ++++++++++++++++---------
 2 files changed, 29 insertions(+), 18 deletions(-)

diff --git a/lib/goo/base/filter.rb b/lib/goo/base/filter.rb
index 66f2095d..50fa58ec 100644
--- a/lib/goo/base/filter.rb
+++ b/lib/goo/base/filter.rb
@@ -11,50 +11,54 @@ def initialize(pattern)
       end
 
       def >(value)
-        @filter_tree << FILTER_TUPLE.new(:>,value)
+        @filter_tree << FILTER_TUPLE.new(:>, value)
         self
       end
 
       def <(value)
-        @filter_tree << FILTER_TUPLE.new(:<,value)
+        @filter_tree << FILTER_TUPLE.new(:<, value)
         self
       end
 
       def <=(value)
-        @filter_tree << FILTER_TUPLE.new(:<=,value)
+        @filter_tree << FILTER_TUPLE.new(:<=, value)
         self
       end
 
       def >=(value)
-        @filter_tree << FILTER_TUPLE.new(:>=,value)
+        @filter_tree << FILTER_TUPLE.new(:>=, value)
         self
       end
 
       def or(value)
-        @filter_tree << FILTER_TUPLE.new(:or,value)
+        @filter_tree << FILTER_TUPLE.new(:or, value)
         self
       end
 
       def ==(value)
-        @filter_tree << FILTER_TUPLE.new(:==,value)
+        @filter_tree << FILTER_TUPLE.new(:==, value)
         self
       end
 
       def and(value)
-        @filter_tree << FILTER_TUPLE.new(:and,value)
+        @filter_tree << FILTER_TUPLE.new(:and, value)
         self
       end
 
       def unbound
-        @filter_tree << FILTER_TUPLE.new(:unbound,nil)
+        @filter_tree << FILTER_TUPLE.new(:unbound, nil)
         self
       end
 
       def bound
-        @filter_tree << FILTER_TUPLE.new(:bound,nil)
+        @filter_tree << FILTER_TUPLE.new(:bound, nil)
         self
       end
 
+      def regex(value)
+        @filter_tree << FILTER_TUPLE.new(:regex, value)
+        self 
+      end
     end
   end
 end
diff --git a/lib/goo/sparql/queries.rb b/lib/goo/sparql/queries.rb
index 8ed102dd..7cc04642 100644
--- a/lib/goo/sparql/queries.rb
+++ b/lib/goo/sparql/queries.rb
@@ -131,22 +131,29 @@ def self.query_filter_sparql(klass,filter,filter_patterns,filter_graphs,
           end
           filter_var = inspected_patterns[filter_pattern_match]
           if !filter_operation.value.instance_of?(Goo::Filter)
-            unless filter_operation.operator == :unbound || filter_operation.operator == :bound
+            case filter_operation.operator
+            when  :unbound
+              filter_operations << "!BOUND(?#{filter_var.to_s})"
+              return :optional
+
+            when :bound
+              filter_operations << "BOUND(?#{filter_var.to_s})"
+              return :optional
+            when :regex
+              if  filter_operation.value.is_a?(String)
+                filter_operations << "REGEX(?#{filter_var.to_s} , \"#{filter_operation.value.to_s}\")"
+              end
+
+            else
               value = RDF::Literal.new(filter_operation.value)
               if filter_operation.value.is_a? String
                 value = RDF::Literal.new(filter_operation.value, :datatype => RDF::XSD.string)
               end
               filter_operations << (
                 "?#{filter_var.to_s} #{sparql_op_string(filter_operation.operator)} " +
-                " #{value.to_ntriples}")
-            else
-              if filter_operation.operator == :unbound
-                filter_operations << "!BOUND(?#{filter_var.to_s})"
-              else
-                filter_operations << "BOUND(?#{filter_var.to_s})"
-              end
-              return :optional
+                  " #{value.to_ntriples}")
             end
+
           else
             filter_operations << "#{sparql_op_string(filter_operation.operator)}"
             query_filter_sparql(klass,filter_operation.value,filter_patterns,