refining complex formulas

config/locales/en.yml

@@ -37,7 +37,7 @@ en:
               unparsable_formula: 'cannot be parsed'
               disallowed_token: 'includes disallowed token "%{token}" (of type: %{ttype})'
               disallowed_keyword: 'includes disallowed keyword: "%{keyword}"'
-              disallowed_function: 'includes disallowed function call: %{function}'
+              disallowed_method: 'includes disallowed method call: %{method}'
               unknown_quantity: 'contains undefined quantity: %{quantity}'
   body_trackers:
     index:

test/ripper.rb

@@ -1,24 +1,45 @@
 require 'ripper'
+require 'set'
 require 'pp'
 require 'byebug'
 
 class DemoBuilder < Ripper::SexpBuilder
   def initialize(*args)
     super(*args)
-    @errors = []
-    @identifiers = []
+    @disallowed = Hash.new { |h,k| h[k] = Set.new }
+    @identifiers = Set.new
+    @paramed_formula = nil
     @arguments = []
   end
 
+  def errors
+    @errors = []
+    @disallowed[:token].each { |t, e| @errors << [:disallowed_token, {token: t, ttype: e}] }
+    @disallowed[:method].each { |f| @errors << [:disallowed_method, {method: f}] }
+    @disallowed[:keyword].each { |k| @errors << [:disallowed_keyword, {keyword: k}] }
+    @errors
+  end
+
+  private
+
+  METHODS = ['abs', 'nil?']
+
   events = private_instance_methods(false).grep(/\Aon_/) {$'.to_sym}
   (PARSER_EVENTS - events).each do |event|
     module_eval(<<-End, __FILE__, __LINE__ + 1)
       def on_#{event}(*args)
-        super.tap { |result| p result }
+        @disallowed[:token] << [args[1], event]
       end
     End
   end
 
+  def on_program(stmts)
+    puts @identifiers.inspect
+    @paramed_formula = join_stmts(stmts)
+    puts @paramed_formula
+    puts @arguments.inspect
+  end
+
   def on_args_new
     []
   end
@@ -37,10 +58,10 @@ class DemoBuilder < Ripper::SexpBuilder
     args.map do |arg|
       ttype, token = arg
       case ttype
-      when :quantity
+      when :bt_quantity
         "params['#{token}']"
-      when :indexed_expr
-        # FIXME: token expression has to be evaluated in block with _index and
+      when :bt_expression
+        # FIXME: 'token' expression has to be evaluated in block with _index and
         # result stored in @arguments
         @arguments << token
         "args['#{@arguments.length - 1}']"
@@ -51,48 +72,105 @@ class DemoBuilder < Ripper::SexpBuilder
     ")"
   end
 
-  #def on_call(left, dot, right)
-  #  "#{left}#{dot}#{right}"
-  #end
+  def on_stmts_new
+    []
+  end
 
-  #def on_method_add_arg(method, arg)
-  #  "#{method}#{arg}"
-  #end
+  def on_stmts_add(stmts, new_stmt)
+    stmts << new_stmt
+  end
+
+  def on_paren(stmts)
+    [
+      :bt_expression,
+      "(" << join_stmts(stmts) << ")"
+    ]
+  end
+
+  def on_call(left, dot, right)
+    [
+      :bt_method_call,
+      case left[0]
+      when :bt_quantity
+        "params['#{left[1]}']"
+      when :bt_method_call
+        "#{left[1]}"
+      else
+        raise NotImplementedError
+      end <<
+      dot.to_s <<
+      case right[0]
+      when :bt_method
+        right[1]
+      else
+        raise NotImplementedError
+      end
+    ]
+  end
+
+  def on_fcall(token)
+    @disallowed[:method] = token[1]
+    [:bt_method, token[1]]
+  end
+
+  def on_vcall(token)
+    @identifiers << token[1]
+    [:bt_quantity, token[1]]
+  end
+  
+  def on_method_add_arg(method, paren)
+    [
+      :bt_method_call,
+      "#{method[1]}#{paren}"
+    ]
+  end
 
   def on_binary(left, op, right)
     [
-      :indexed_expr,
+      :bt_expression,
       [left, right].map do |side|
-        side[0] == :quantity ? "params['#{side[1]}'][_index]" : "#{side[1]}"
+        side[0] == :bt_quantity ? "params['#{side[1]}'][_index]" : "#{side[1]}"
       end.join(op.to_s)
     ]
   end
 
   def on_var_ref(var_ref)
-    ttype, name = var_ref
-    if ttype == :quantity_name
-      [:quantity, name] 
-    else
-      raise NotImplementedError
-    end
+    var_ref[0] == :bt_quantity ? var_ref : raise(NotImplementedError)
   end
 
-  SCANNER_EVENTS.each do |event|
+  silenced_events = [:lparen, :rparen, :op, :period, :sp, :int, :float]
+  (SCANNER_EVENTS - silenced_events).each do |event|
     module_eval(<<-End, __FILE__, __LINE__ + 1)
-      def on_#{event}(tok)
-        super.tap { |result| p result }
-        #super
+      def on_#{event}(token)
+        @disallowed[:token] << [token, event]
       end
     End
   end
 
   def on_const(token)
     @identifiers << token
-    [:quantity_name, token]
+    [:bt_quantity, token]
   end
 
   def on_ident(token)
-    token
+    @disallowed[:method] << token unless METHODS.include?(token)
+    [:bt_method, token]
+  end
+
+  def on_kw(token)
+    @disallowed[:keyword] << token unless token == 'nil'
+  end
+
+  def join_stmts(stmts)
+    stmts.map do |stmt|
+      ttype, token = stmt
+      case ttype
+      when :bt_expression
+        token
+      else
+        raise NotImplementedError
+      end
+    end.join(';')
   end
 end
 
@@ -100,4 +178,5 @@ end
 src = "(Weight/Height.all(3*Dupa).lastBefore(TakenAt)^2) + 2*Other*Other"
 #src = "a = 2; b = a"
 pp DemoBuilder.new(src).parse
+puts "(params['Weight'][_index]/params['Height'].all(args['0']).lastBefore(params['TakenAt'])^2)+2*params['Other'][_index]*params['Other'][_index]"
 pp Ripper.sexp_raw(src)