groovy/step0_repl.groovy

   1 // READ
   2 READ = { str ->
   3     str
   4 }
   5
   6 // EVAL
   7 EVAL = { ast, env ->
   8     ast
   9 }
  10
  11 // PRINT
  12 PRINT = { exp ->
  13     exp
  14 }
  15
  16 // REPL
  17 REP = { str ->
  18     PRINT(EVAL(READ(str), [:]))
  19 }
  20
  21 while (true) {
  22     line = System.console().readLine 'user> '
  23     if (line == null) {
  24         break
  25     }
  26     try {
  27         println REP(line)
  28     } catch(ex) {
  29         println "Error: $ex"
  30         ex.printStackTrace()
  31     }
  32 }