lib/nydp/runner.rb in nydp-0.0.4 vs lib/nydp/runner.rb in nydp-0.0.5

@@ -1,7 +1,44 @@
+require 'readline'
+require 'nydp/readline_history'
+
 module Nydp
-  class Runner
+  class StringReader
+    def initialize string ; @string = string ; end
+    def nextline
+      s = @string ; @string = nil ; s
+    end
+  end
+
+  class StreamReader
+    def initialize stream ; @stream = stream ; end
+    def nextline
+      @stream.readline unless @stream.eof?
+    end
+  end
+
+  class ReadlineReader
+    include Nydp::ReadlineHistory
+
+    def initialize stream, prompt
+      @prompt = prompt
+      setup_readline_history
+    end
+
+    # with thanks to http://ruby-doc.org/stdlib-1.9.3/libdoc/readline/rdoc/Readline.html
+    # and http://bogojoker.com/readline/
+    def nextline
+      line = Readline.readline(@prompt, true)
+      return nil if line.nil?
+      if line =~ /^\s*$/ or Readline::HISTORY.to_a[-2] == line
+        Readline::HISTORY.pop
+      end
+      line
+    end
+  end
+
+  class Evaluator
     attr_accessor :vm, :ns
 
     def initialize vm, ns
       @vm = vm
       @ns = ns
@@ -28,39 +65,36 @@
     def evaluate expr
       compile_and_eval(pre_compile(expr))
     end
   end
 
-  class StreamRunner < Runner
-    attr_accessor :stream, :parser
-
-    def initialize vm, ns, stream
+  class Runner < Evaluator
+    def initialize vm, ns, stream, printer=nil
       super vm, ns
-      @stream = stream
-      @parser = Nydp::Parser.new(ns)
-      @tokens = Nydp::Tokeniser.new stream
+      @printer    = printer
+      @parser     = Nydp::Parser.new(ns)
+      @tokens     = Nydp::Tokeniser.new stream
     end
 
-    def prompt *_
+    def print val
+      @printer.puts val if @printer
     end
 
     def run
       res = Nydp.NIL
-      prompt
       while !@tokens.finished
-        expr = parser.expression(@tokens)
+        expr = @parser.expression(@tokens)
         unless expr.nil?
-          res = evaluate expr
-          prompt res
+          begin
+            print(res = evaluate(expr))
+          rescue Exception => e
+            puts e.message
+            e.backtrace.each do |b|
+              puts b
+            end
+          end
         end
       end
       res
-    end
-  end
-
-  class Repl < StreamRunner
-    def prompt val=nil
-      puts val if val
-      print "nydp > "
     end
   end
 end