Class: Heist::REPL

Inherits:
Object
  • Object
show all
Defined in:
lib/repl.rb

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ REPL

Returns a new instance of REPL.



6
7
8
9
10
11
12
13
14
 
# File 'lib/repl.rb', line 6

def initialize(options = {})
  @runtime = Runtime.new(options)
  @scope = Runtime::FileScope.new(@runtime.top_level, File.expand_path('.'))
  @results = []
  
  @runtime.define('~') { |x| @results[-x] }
  
  reset!
end

Instance Method Details

#run ⇒ Object 



16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
 
# File 'lib/repl.rb', line 16

def run
  puts @runtime.info
  
  Readline.completion_append_character = nil
  Readline.completion_proc = @runtime.top_level.method(:longest_prefix)
  
  loop do
    begin
      input  = Readline.readline(prompt)
      exit if input.nil?
      
      push(input)
      tree = Heist.parse(@buffer * "\n")
      next if tree.nil?
      
      reset!
      result = @scope.eval(tree)
      unless result.nil?
        puts "; => #{ Heist.stringify(result) }\n\n"
        @results << result
        @scope['^'] = result
      end
      
    rescue Exception => ex
      return if SystemExit === ex
      if Interrupt === ex
        reset! and puts "\n\n"
      else
        puts "; [error] #{ ex.message }\n\n"
      end
      
    # debugging
    #  puts "; backtrace: " + ex.backtrace.join("\n;            ") +
    #    "\n\n" unless Heist::RuntimeError === ex
    end
  end
end