plpgsql/printer.sql

   1 -- ---------------------------------------------------------
   2 -- printer.sql
   3
   4 CREATE SCHEMA printer;
   5
   6 CREATE FUNCTION printer.pr_str_array(arr integer[],
   7     sep varchar, print_readably boolean)
   8     RETURNS varchar AS $$
   9 DECLARE
  10     i    integer;
  11     res  varchar[];
  12 BEGIN
  13     IF array_length(arr, 1) > 0 THEN
  14         FOR i IN array_lower(arr, 1) .. array_upper(arr, 1)
  15         LOOP
  16             res := array_append(res, printer.pr_str(arr[i], print_readably));
  17         END LOOP;
  18         RETURN array_to_string(res, sep);
  19     ELSE
  20         RETURN '';
  21     END IF;
  22 END; $$ LANGUAGE plpgsql;
  23
  24 CREATE FUNCTION printer.pr_str(ast integer,
  25     print_readably boolean DEFAULT true)
  26     RETURNS varchar AS $$
  27 DECLARE
  28     type  integer;
  29     seq   integer[];
  30     hash  hstore;
  31     cid   integer;
  32     vid   integer;
  33     pid   integer;
  34     str   varchar;
  35 BEGIN
  36     -- RAISE NOTICE 'pr_str ast: %', ast;
  37     SELECT type_id FROM types.value WHERE value_id = ast INTO type;
  38     -- RAISE NOTICE 'pr_str type: %', type;
  39     CASE
  40     WHEN type = 0 THEN RETURN 'nil';
  41     WHEN type = 1 THEN RETURN 'false';
  42     WHEN type = 2 THEN RETURN 'true';
  43     WHEN type = 3 THEN  -- integer
  44         RETURN CAST((SELECT val_int
  45                      FROM types.value WHERE value_id = ast) as varchar);
  46     WHEN type = 5 THEN  -- string
  47         str := types._valueToString(ast);
  48         IF chr(CAST(x'7f' AS integer)) = substring(str FROM 1 FOR 1) THEN
  49             RETURN ':' || substring(str FROM 2 FOR (char_length(str)-1));
  50         ELSIF print_readably THEN
  51             str := replace(str, E'\\', '\\');
  52             str := replace(str, '"', '\"');
  53             str := replace(str, E'\n', '\n');
  54             RETURN '"' || str || '"';
  55         ELSE
  56             RETURN str;
  57         END IF;
  58     WHEN type = 7 THEN  -- symbol
  59         RETURN types._valueToString(ast);
  60     WHEN type = 8 THEN  -- list
  61         BEGIN
  62             SELECT val_seq INTO seq FROM types.value WHERE value_id = ast;
  63             RETURN '(' ||
  64                    array_to_string(array(
  65                         SELECT printer.pr_str(x, print_readably)
  66                             FROM unnest(seq) AS x), ' ') ||
  67                    ')';
  68         END;
  69     WHEN type = 9 THEN  -- vector
  70         BEGIN
  71             SELECT val_seq INTO seq FROM types.value WHERE value_id = ast;
  72             RETURN '[' ||
  73                    array_to_string(array(
  74                         SELECT printer.pr_str(x, print_readably)
  75                             FROM unnest(seq) AS x), ' ') ||
  76                    ']';
  77         END;
  78     WHEN type = 10 THEN  -- hash-map
  79         BEGIN
  80             SELECT val_hash INTO hash FROM types.value WHERE value_id = ast;
  81             RETURN '{' ||
  82                    array_to_string(array(
  83                         SELECT printer.pr_str(CAST(key AS integer),
  84                                               print_readably) || ' ' ||
  85                                printer.pr_str(CAST(value AS integer),
  86                                               print_readably)
  87                         FROM each(hash)), ' ') ||
  88                    '}';
  89         END;
  90     WHEN type = 11 THEN  -- native function
  91         RETURN '#<function ' ||
  92                (SELECT val_string FROM types.value WHERE value_id = ast) ||
  93                '>';
  94     WHEN type = 12 THEN  -- mal function
  95         BEGIN
  96             SELECT ast_id, params_id
  97                 INTO vid, pid
  98                 FROM types.value WHERE value_id = ast;
  99             RETURN '(fn* ' || printer.pr_str(pid, print_readably) ||
 100                    ' ' || printer.pr_str(vid, print_readably) || ')';
 101         END;
 102     WHEN type = 13 THEN  -- atom
 103         BEGIN
 104             SELECT val_seq[1] INTO vid
 105                 FROM types.value WHERE value_id = ast;
 106             RETURN '(atom ' || printer.pr_str(vid, print_readably) || ')';
 107         END;
 108     ELSE
 109         RETURN 'unknown';
 110     END CASE;
 111 END; $$ LANGUAGE plpgsql;