renamed strategy method to format

  - strategy (the method on scalar and attribute) is a complex double-dispatching
    scheme to format (to_sql) a scalar in the light of the particular attribute;
    that is, it casts strings to integers if the column is int, etc.

6 files changed, 21 insertions, 16 deletions

diff --git a/TODO b/TODO
index 45bc9c4f2f..5ef1573c38 100644
--- a/TODO
+++ b/TODO
@@ -1,6 +1,5 @@
 todo:
 - clarify distinction between engine and connection: an engine is a connection pool, plus the quoting operations
-- #relation is now on scalar, attribute and relation; you must admit it's name is confusing given that e.g., relation already has a strategy (Sql::Relation) ... should it be called predicate strategy? operand1.to_sql(operand2.predicate) maybe prefer operand1.cast(operand2) or project or in light of
 - clean up integration tests in join - i find the aggregate stuff too integrationy; unit testing would be better
 - test relation, table reset
 - cache expiry on write
@@ -46,3 +45,5 @@ done:
 - hash custom matcher
 - make session engine stuff follow laws of demeter - currently doing some odd method chaining? rethink who is responsible for what
   - session just calls execute, passing in a connection; by default it gets a connection from the relation.
+- #strategy is now on scalar, attribute and relation; you must admit it's name is confusing given that e.g., relation already has a strategy (Sql::Relation) ... should it be called predicate strategy? operand1.to_sql(operand2.predicate) maybe prefer operand1.cast(operand2) or project or in light of
+  - renamed to #format: operand1.format(operand2)
diff --git a/lib/active_relation/predicates.rb b/lib/active_relation/predicates.rb
index ba926a86e5..12ddd1b48d 100644
--- a/lib/active_relation/predicates.rb
+++ b/lib/active_relation/predicates.rb
@@ -25,7 +25,7 @@ module ActiveRelation
     end
 
     def to_sql(strategy = nil)
-      "#{operand1.to_sql(operand2.strategy)} #{predicate_sql} #{operand2.to_sql(operand1.strategy)}"
+      "#{operand2.format(operand1)} #{predicate_sql} #{operand1.format(operand2)}"
     end
     
     def descend
diff --git a/lib/active_relation/primitives/attribute.rb b/lib/active_relation/primitives/attribute.rb
index 20677f824b..bbea7b4554 100644
--- a/lib/active_relation/primitives/attribute.rb
+++ b/lib/active_relation/primitives/attribute.rb
@@ -111,15 +111,19 @@ module ActiveRelation
     end
     include Expressions
 
-    def to_sql(strategy = self.strategy)
+    def to_sql(strategy = Sql::Predicate.new(engine))
       strategy.attribute prefix, name, self.alias
     end
     
+    def format(object)
+      object.to_sql(strategy)
+    end
+    
+    private
     def strategy
       Sql::Attribute.new(self)
     end
     
-    private
     def prefix
       relation.prefix_for(self)
     end
diff --git a/lib/active_relation/primitives/scalar.rb b/lib/active_relation/primitives/scalar.rb
index fa88404ee3..d428541a50 100644
--- a/lib/active_relation/primitives/scalar.rb
+++ b/lib/active_relation/primitives/scalar.rb
@@ -6,12 +6,12 @@ module ActiveRelation
       @value, @relation = value, relation
     end
     
-    def to_sql(strategy = self.strategy)
+    def to_sql(strategy = Sql::Predicate.new(relation.engine))
       strategy.scalar value
     end
 
-    def strategy
-      ActiveRelation::Sql::Scalar.new(relation.engine)
+    def format(object)
+      object.to_sql(Sql::Scalar.new(relation.engine))
     end
     
     def ==(other)
diff --git a/lib/active_relation/relations/relation.rb b/lib/active_relation/relations/relation.rb
index 69935a7be0..ee2e00aa21 100644
--- a/lib/active_relation/relations/relation.rb
+++ b/lib/active_relation/relations/relation.rb
@@ -132,8 +132,8 @@ module ActiveRelation
       self
     end
     
-    def strategy
-      Sql::Predicate.new(engine)
+    def format(object)
+      object.to_sql(Sql::Predicate.new(engine))
     end
 
     def attributes;  []  end
diff --git a/lib/active_relation/sql.rb b/lib/active_relation/sql.rb
index 99cfc66383..ff00223ce7 100644
--- a/lib/active_relation/sql.rb
+++ b/lib/active_relation/sql.rb
@@ -4,8 +4,8 @@ module ActiveRelation
       delegate :quote_table_name, :quote_column_name, :quote, :to => :engine
     end
     
-    # module Formatting Context / Strategy # unit test me!!!
-    class Strategy
+    # unit test me!!!
+    class Formatter
       attr_reader :engine
       include Quoting
       
@@ -14,7 +14,7 @@ module ActiveRelation
       end
     end
     
-    class Projection < Strategy
+    class Projection < Formatter
       def attribute(relation_name, attribute_name, aliaz)
         "#{quote_table_name(relation_name)}.#{quote_column_name(attribute_name)}" + (aliaz ? " AS #{quote(aliaz.to_s)}" : "")
       end
@@ -24,7 +24,7 @@ module ActiveRelation
       end
     end
     
-    class Predicate < Strategy
+    class Predicate < Formatter
       def attribute(relation_name, attribute_name, aliaz)
         "#{quote_table_name(relation_name)}.#{quote_column_name(attribute_name)}"
       end
@@ -38,19 +38,19 @@ module ActiveRelation
       end
     end
     
-    class Selection < Strategy
+    class Selection < Formatter
       def scalar(scalar)
         scalar
       end
     end
     
-    class Relation < Strategy
+    class Relation < Formatter
       def select(select_sql, aliaz)
         select_sql
       end
     end
     
-    class Aggregation < Strategy
+    class Aggregation < Formatter
       def select(select_sql, aliaz)
         "(#{select_sql}) AS #{engine.quote_table_name(aliaz)}"
       end