rename SYSEVAL→SHEVAL, move code into program to avoid error when building gem

lib/rpl.rb

@@ -5,7 +5,7 @@ require 'rpl/types'
 require 'rpl/words'
 
 class Rpl < Interpreter
-  VERSION = '0.16.0'
+  VERSION = '0.16.1'
 
   include Types
 
@@ -64,7 +64,6 @@ class Rpl < Interpreter
   prepend RplLang::Words::Store
   prepend RplLang::Words::String
   prepend RplLang::Words::StringAndList
-  prepend RplLang::Words::System
   prepend RplLang::Words::Test
   prepend RplLang::Words::TimeAndDate
   prepend RplLang::Words::Trig

lib/rpl/words.rb

@@ -18,5 +18,4 @@ require 'rpl/words/time-date'
 require 'rpl/words/trig'
 require 'rpl/words/logarithm'
 require 'rpl/words/filesystem'
-require 'rpl/words/system'
 require 'rpl/words/list'

lib/rpl/words/program.rb

@@ -23,6 +23,15 @@ module RplLang
                                  end
                                end )
 
+        @dictionary.add_word!( ['sheval'],
+                               category,
+                               '( string -- output ) run string in OS shell and put output on stack',
+                               proc do
+                                 args = stack_extract( [[RplString]] )
+
+                                 @stack << Types.new_object( RplString, "\"#{`#{args[0].value}`}\"" )
+                               end )
+
         @dictionary.add_word!( ['↴', 'lsto'],
                                category,
                                '( content name -- ) store to local variable',

lib/rpl/words/system.rb

@@ -1,24 +0,0 @@
-# frozen_string_literal: true
-
-module RplLang
-  module Words
-    module System
-      include Types
-
-      def populate_dictionary
-        super
-
-        category = 'System'
-
-        @dictionary.add_word!( ['syseval'],
-                               category,
-                               '( string -- output ) run string in OS shell and put output on stack',
-                               proc do
-                                 args = stack_extract( [[RplString]] )
-
-                                 @stack << Types.new_object( RplString, "\"#{`#{args[0].value}`}\"" )
-                               end )
-      end
-    end
-  end
-end