plsql/step1_read_print.sql

   1 @io.sql
   2 @types.sql
   3 @reader.sql
   4 @printer.sql
   5
   6 CREATE OR REPLACE PACKAGE mal IS
   7
   8 FUNCTION MAIN(args varchar DEFAULT '()') RETURN integer;
   9
  10 END mal;
  11 /
  12
  13 CREATE OR REPLACE PACKAGE BODY mal IS
  14
  15 FUNCTION MAIN(args varchar DEFAULT '()') RETURN integer IS
  16     M         types.mal_table;                 -- general mal value memory pool
  17     H         types.map_entry_table;    -- hashmap memory pool
  18     line      CLOB;
  19
  20     -- read
  21     FUNCTION READ(line varchar) RETURN integer IS
  22     BEGIN
  23         RETURN reader.read_str(M, H, line);
  24     END;
  25
  26     -- eval
  27     FUNCTION EVAL(ast integer, env varchar) RETURN integer IS
  28     BEGIN
  29         RETURN ast;
  30     END;
  31
  32     -- print
  33     FUNCTION PRINT(exp integer) RETURN varchar IS
  34     BEGIN
  35         RETURN printer.pr_str(M, H, exp);
  36     END;
  37
  38     -- repl
  39     FUNCTION REP(line varchar) RETURN varchar IS
  40     BEGIN
  41         RETURN PRINT(EVAL(READ(line), ''));
  42     END;
  43
  44 BEGIN
  45     -- initialize memory pools
  46     M := types.mem_new();
  47     H := types.map_entry_table();
  48
  49     WHILE true LOOP
  50         BEGIN
  51             line := io.readline('user> ', 0);
  52             IF line = EMPTY_CLOB() THEN CONTINUE; END IF;
  53             IF line IS NOT NULL THEN
  54                 io.writeline(REP(line));
  55             END IF;
  56
  57             EXCEPTION WHEN OTHERS THEN
  58                 IF SQLCODE = -20001 THEN  -- io read stream closed
  59                     io.writeline('closing stream 1');
  60                     io.close(1);  -- close output stream
  61                     RETURN 0;
  62                 END IF;
  63                 io.writeline('Error: ' || SQLERRM);
  64                 io.writeline(dbms_utility.format_error_backtrace);
  65         END;
  66     END LOOP;
  67 END;
  68
  69 END mal;
  70 /
  71 show errors;
  72
  73 quit;