python/step1_read_print.py

   1 import sys, traceback
   2 import mal_readline
   3 import mal_types as types
   4 import reader, printer
   5
   6 # read
   7 def READ(str):
   8     return reader.read_str(str)
   9
  10 # eval
  11 def EVAL(ast, env):
  12         #print("EVAL %s" % printer._pr_str(ast))
  13         return ast
  14
  15 # print
  16 def PRINT(exp):
  17     return printer._pr_str(exp)
  18
  19 # repl
  20 def REP(str):
  21     return PRINT(EVAL(READ(str), {}))
  22
  23 # repl loop
  24 while True:
  25     try:
  26         line = mal_readline.readline("user> ")
  27         if line == None: break
  28         if line == "": continue
  29         print(REP(line))
  30     except reader.Blank: continue
  31     except Exception as e:
  32         print("".join(traceback.format_exception(*sys.exc_info())))