evaluate for enumerable function fully evaluates

README.md

@@ -119,6 +119,9 @@ calculator.evaluate("f(0-a)", a: 2)
 #=> -20
 calculator.evaluate("n") # n only exists in the definition of f(x)
 #=> Keisan::Exceptions::UndefinedVariableError: n
+calculator.evaluate("includes(a, element) = a.reduce(false, found, x, found || (x == element))")
+calculator.evaluate("[3, 9].map(x, [1, 3, 5].includes(x))").value
+#=> [true, false]
 ```
 
 This form even supports recursion, but you must explicitly allow it.

lib/keisan/functions/enumerable_function.rb

@@ -12,6 +12,14 @@ def value(ast_function, context = nil)
         evaluate(ast_function, context)
       end
 
+      def unbound_variables(children, context)
+        super - Set.new(shadowing_variable_names(children).map(&:name))
+      end
+
+      def shadowing_variable_names(children)
+        raise Exceptions::NotImplementedError.new
+      end
+
       def evaluate(ast_function, context = nil)
         validate_arguments!(ast_function.children.count)
         context ||= Context.new
@@ -20,9 +28,9 @@ def evaluate(ast_function, context = nil)
 
         case operand
         when AST::List
-          evaluate_list(operand, arguments, expression, context)
+          evaluate_list(operand, arguments, expression, context).evaluate(context)
         when AST::Hash
-          evaluate_hash(operand, arguments, expression, context)
+          evaluate_hash(operand, arguments, expression, context).evaluate(context)
         else
           raise Exceptions::InvalidFunctionError.new("Unhandled first argument to #{name}: #{operand}")
         end

lib/keisan/functions/filter.rb

@@ -10,11 +10,11 @@ def initialize
         super("filter")
       end
 
-      def unbound_variables(children, context)
+      def shadowing_variable_names(children)
         if children.size == 3
-          super - Set[children[1].name]
+          children[1..1]
         else
-          super - Set[children[1].name, children[2].name]
+          children[1..2]
         end
       end
 

lib/keisan/functions/map.rb

@@ -10,11 +10,11 @@ def initialize
         super("map")
       end
 
-      def unbound_variables(children, context)
+      def shadowing_variable_names(children)
         if children.size == 3
-          super - Set[children[1].name]
+          children[1..1]
         else
-          super - Set[children[1].name, children[2].name]
+          children[1..2]
         end
       end
 

lib/keisan/functions/reduce.rb

@@ -11,11 +11,11 @@ def initialize
         super("reduce")
       end
 
-      def unbound_variables(children, context)
+      def shadowing_variable_names(children)
         if children.size == 5
-          super - Set[children[2].name, children[3].name]
+          children[2..3]
         else
-          super - Set[children[2].name, children[3].name, children[4].name]
+          children[2..4]
         end
       end
 

spec/keisan/ast/function_assignment_spec.rb

@@ -27,5 +27,8 @@
     calculator = Keisan::Calculator.new
     calculator.evaluate("minimum(a) = a.reduce(INF, current_min, element, if (element < current_min, element, current_min))")
     expect(calculator.evaluate("minimum([5,1,3])")).to eq 1
+
+    calculator.evaluate("includes(a, element) = a.reduce(false, found, x, found || (x == element))")
+    expect(calculator.evaluate("[3, 9].map(x, [1, 3, 5].includes(x))")).to eq([true, false])
   end
 end

spec/readme_spec.rb

@@ -13,7 +13,7 @@
       digest = Digest::SHA256.hexdigest(content)
 
       # cat README.md | sha256sum
-      expected_digest = "399be39e65ec8aaace1f9ce266415bf49627572bcd2ee6f8e05d9f4a62cc241c"
+      expected_digest = "c430ca4bd926e553e7414c96f89b8f81ef8bf3c491c5484e9f9599f38e06e2f7"
       if digest != expected_digest
         raise "Invalid README file detected with SHA256 digest of #{digest}. Use command `cat README.md | sha256sum` to get correct digest if your changes to the README are safe. Aborting README test."
       end