Refactor predication methods to be available to SqlLiterals as well.

1 files changed, 177 insertions, 0 deletions

diff --git a/lib/arel/predications.rb b/lib/arel/predications.rb
new file mode 100644
index 0000000000..8a8960f0b1
--- /dev/null
+++ b/lib/arel/predications.rb
@@ -0,0 +1,177 @@
+module Arel
+  module Predications
+    def not_eq other
+      Nodes::NotEqual.new self, other
+    end
+
+    def not_eq_any others
+      grouping_any :not_eq, others
+    end
+
+    def not_eq_all others
+      grouping_all :not_eq, others
+    end
+
+    def eq other
+      Nodes::Equality.new self, other
+    end
+
+    def eq_any others
+      grouping_any :eq, others
+    end
+
+    def eq_all others
+      grouping_all :eq, others
+    end
+
+    def in other
+      case other
+      when Arel::SelectManager
+        Nodes::In.new self, other.to_a.map { |x| x.id }
+      when Range
+        if other.exclude_end?
+          left  = Nodes::GreaterThanOrEqual.new(self, other.min)
+          right = Nodes::LessThan.new(self, other.max + 1)
+          Nodes::And.new left, right
+        else
+          Nodes::Between.new(self, Nodes::And.new(other.min, other.max))
+        end
+      else
+        Nodes::In.new self, other
+      end
+    end
+
+    def in_any others
+      grouping_any :in, others
+    end
+
+    def in_all others
+      grouping_all :in, others
+    end
+
+    def not_in other
+      case other
+      when Arel::SelectManager
+        Nodes::NotIn.new self, other.to_a.map { |x| x.id }
+      when Range
+        if other.exclude_end?
+          left  = Nodes::LessThan.new(self, other.min)
+          right = Nodes::GreaterThanOrEqual.new(self, other.max)
+          Nodes::Or.new left, right
+        else
+          left  = Nodes::LessThan.new(self, other.min)
+          right = Nodes::GreaterThan.new(self, other.max)
+          Nodes::Or.new left, right
+        end
+      else
+        Nodes::NotIn.new self, other
+      end
+    end
+
+    def not_in_any others
+      grouping_any :not_in, others
+    end
+
+    def not_in_all others
+      grouping_all :not_in, others
+    end
+
+    def matches other
+      Nodes::Matches.new self, other
+    end
+
+    def matches_any others
+      grouping_any :matches, others
+    end
+
+    def matches_all others
+      grouping_all :matches, others
+    end
+
+    def does_not_match other
+      Nodes::DoesNotMatch.new self, other
+    end
+
+    def does_not_match_any others
+      grouping_any :does_not_match, others
+    end
+
+    def does_not_match_all others
+      grouping_all :does_not_match, others
+    end
+
+    def gteq right
+      Nodes::GreaterThanOrEqual.new self, right
+    end
+
+    def gteq_any others
+      grouping_any :gteq, others
+    end
+
+    def gteq_all others
+      grouping_all :gteq, others
+    end
+
+    def gt right
+      Nodes::GreaterThan.new self, right
+    end
+
+    def gt_any others
+      grouping_any :gt, others
+    end
+
+    def gt_all others
+      grouping_all :gt, others
+    end
+
+    def lt right
+      Nodes::LessThan.new self, right
+    end
+
+    def lt_any others
+      grouping_any :lt, others
+    end
+
+    def lt_all others
+      grouping_all :lt, others
+    end
+
+    def lteq right
+      Nodes::LessThanOrEqual.new self, right
+    end
+
+    def lteq_any others
+      grouping_any :lteq, others
+    end
+
+    def lteq_all others
+      grouping_all :lteq, others
+    end
+
+    def asc
+      Nodes::Ordering.new self, :asc
+    end
+
+    def desc
+      Nodes::Ordering.new self, :desc
+    end
+
+    private
+
+    def grouping_any method_id, others
+      first = send method_id, others.shift
+
+      Nodes::Grouping.new others.inject(first) { |memo,expr|
+        Nodes::Or.new(memo, send(method_id, expr))
+      }
+    end
+
+    def grouping_all method_id, others
+      first = send method_id, others.shift
+
+      Nodes::Grouping.new others.inject(first) { |memo,expr|
+        Nodes::And.new(memo, send(method_id, expr))
+      }
+    end
+  end
+end
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