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mirror of https://github.com/kanaka/mal.git synced 2024-11-11 00:52:44 +03:00
mal/plsql/step8_macros.sql
2016-05-22 00:16:02 -06:00

369 lines
12 KiB
SQL

@io.sql
@types.sql
@reader.sql
@printer.sql
@env.sql
@core.sql
CREATE OR REPLACE PACKAGE mal IS
FUNCTION MAIN(args varchar DEFAULT '()') RETURN integer;
END mal;
/
CREATE OR REPLACE PACKAGE BODY mal IS
FUNCTION MAIN(args varchar DEFAULT '()') RETURN integer IS
M types.mal_table; -- general mal value memory pool
H types.map_entry_table; -- hashmap memory pool
E env_pkg.env_entry_table; -- mal env memory pool
repl_env integer;
x integer;
line CLOB;
core_ns core_ns_T;
cidx integer;
argv mal_vals;
-- read
FUNCTION READ(line varchar) RETURN integer IS
BEGIN
RETURN reader.read_str(M, H, line);
END;
-- eval
-- forward declarations
FUNCTION EVAL(orig_ast integer, orig_env integer) RETURN integer;
FUNCTION do_builtin(fn integer, args mal_vals) RETURN integer;
FUNCTION is_pair(ast integer) RETURN BOOLEAN IS
BEGIN
RETURN M(ast).type_id IN (8,9) AND types.count(M, ast) > 0;
END;
FUNCTION quasiquote(ast integer) RETURN integer IS
a0 integer;
a00 integer;
BEGIN
IF NOT is_pair(ast) THEN
RETURN types.list(M, types.symbol(M, 'quote'), ast);
ELSE
a0 := types.nth(M, ast, 0);
IF M(a0).type_id = 7 AND
TREAT(m(a0) AS mal_str_T).val_str = 'unquote' THEN
RETURN types.nth(M, ast, 1);
ELSIF is_pair(a0) THEN
a00 := types.nth(M, a0, 0);
IF M(a00).type_id = 7 AND
TREAT(M(a00) AS mal_str_T).val_str = 'splice-unquote' THEN
RETURN types.list(M, types.symbol(M, 'concat'),
types.nth(M, a0, 1),
quasiquote(types.slice(M, ast, 1)));
END IF;
END IF;
RETURN types.list(M, types.symbol(M, 'cons'),
quasiquote(a0),
quasiquote(types.slice(M, ast, 1)));
END IF;
END;
FUNCTION is_macro_call(ast integer, env integer) RETURN BOOLEAN IS
a0 integer;
mac integer;
BEGIN
IF M(ast).type_id = 8 THEN
a0 := types.nth(M, ast, 0);
IF M(a0).type_id = 7 AND
env_pkg.env_find(M, E, env, a0) IS NOT NULL THEN
mac := env_pkg.env_get(M, E, env, a0);
IF M(mac).type_id = 12 THEN
RETURN TREAT(M(mac) AS mal_func_T).is_macro > 0;
END IF;
END IF;
END IF;
RETURN FALSE;
END;
FUNCTION macroexpand(orig_ast integer, env integer) RETURN integer IS
ast integer;
mac integer;
malfn mal_func_T;
fargs mal_vals;
fn_env integer;
BEGIN
ast := orig_ast;
WHILE is_macro_call(ast, env) LOOP
mac := env_pkg.env_get(M, E, env, types.nth(M, ast, 0));
fargs := TREAT(M(types.slice(M, ast, 1)) as mal_seq_T).val_seq;
if M(mac).type_id = 12 THEN
malfn := TREAT(M(mac) AS mal_func_T);
fn_env := env_pkg.env_new(M, E, malfn.env,
malfn.params,
fargs);
ast := EVAL(malfn.ast, fn_env);
ELSE
ast := do_builtin(mac, fargs);
END IF;
END LOOP;
RETURN ast;
END;
FUNCTION eval_ast(ast integer, env integer) RETURN integer IS
i integer;
old_seq mal_vals;
new_seq mal_vals;
new_hm integer;
old_midx integer;
new_midx integer;
k varchar2(256);
BEGIN
IF M(ast).type_id = 7 THEN
RETURN env_pkg.env_get(M, E, env, ast);
ELSIF M(ast).type_id IN (8,9) THEN
old_seq := TREAT(M(ast) AS mal_seq_T).val_seq;
new_seq := mal_vals();
new_seq.EXTEND(old_seq.COUNT);
FOR i IN 1..old_seq.COUNT LOOP
new_seq(i) := EVAL(old_seq(i), env);
END LOOP;
RETURN types.seq(M, M(ast).type_id, new_seq);
ELSIF M(ast).type_id IN (10) THEN
new_hm := types.hash_map(M, H, mal_vals());
old_midx := TREAT(M(ast) AS mal_map_T).map_idx;
new_midx := TREAT(M(new_hm) AS mal_map_T).map_idx;
k := H(old_midx).FIRST();
WHILE k IS NOT NULL LOOP
H(new_midx)(k) := EVAL(H(old_midx)(k), env);
k := H(old_midx).NEXT(k);
END LOOP;
RETURN new_hm;
ELSE
RETURN ast;
END IF;
END;
FUNCTION EVAL(orig_ast integer, orig_env integer) RETURN integer IS
ast integer := orig_ast;
env integer := orig_env;
el integer;
a0 integer;
a0sym varchar2(100);
seq mal_vals;
let_env integer;
i integer;
f integer;
cond integer;
malfn mal_func_T;
args mal_vals;
BEGIN
WHILE TRUE LOOP
-- io.writeline('EVAL: ' || printer.pr_str(M, H, ast));
IF M(ast).type_id <> 8 THEN
RETURN eval_ast(ast, env);
END IF;
-- apply
ast := macroexpand(ast, env);
IF M(ast).type_id <> 8 THEN
RETURN eval_ast(ast, env);
END IF;
IF types.count(M, ast) = 0 THEN
RETURN ast; -- empty list just returned
END IF;
-- apply
a0 := types.first(M, ast);
if M(a0).type_id = 7 THEN -- symbol
a0sym := TREAT(M(a0) AS mal_str_T).val_str;
ELSE
a0sym := '__<*fn*>__';
END IF;
CASE
WHEN a0sym = 'def!' THEN
RETURN env_pkg.env_set(M, E, env,
types.nth(M, ast, 1), EVAL(types.nth(M, ast, 2), env));
WHEN a0sym = 'let*' THEN
let_env := env_pkg.env_new(M, E, env);
seq := TREAT(M(types.nth(M, ast, 1)) AS mal_seq_T).val_seq;
i := 1;
WHILE i <= seq.COUNT LOOP
x := env_pkg.env_set(M, E, let_env,
seq(i), EVAL(seq(i+1), let_env));
i := i + 2;
END LOOP;
env := let_env;
ast := types.nth(M, ast, 2); -- TCO
WHEN a0sym = 'quote' THEN
RETURN types.nth(M, ast, 1);
WHEN a0sym = 'quasiquote' THEN
RETURN EVAL(quasiquote(types.nth(M, ast, 1)), env);
WHEN a0sym = 'defmacro!' THEN
x := EVAL(types.nth(M, ast, 2), env);
malfn := TREAT(M(x) as mal_func_T);
malfn.is_macro := 1;
M(x) := malfn;
RETURN env_pkg.env_set(M, E, env,
types.nth(M, ast, 1), x);
WHEN a0sym = 'macroexpand' THEN
RETURN macroexpand(types.nth(M, ast, 1), env);
WHEN a0sym = 'do' THEN
x := types.slice(M, ast, 1, types.count(M, ast)-2);
x := eval_ast(x, env);
ast := types.nth(M, ast, types.count(M, ast)-1); -- TCO
WHEN a0sym = 'if' THEN
cond := EVAL(types.nth(M, ast, 1), env);
IF cond = 1 OR cond = 2 THEN -- nil or false
IF types.count(M, ast) > 3 THEN
ast := types.nth(M, ast, 3); -- TCO
ELSE
RETURN 1; -- nil
END IF;
ELSE
ast := types.nth(M, ast, 2); -- TCO
END IF;
WHEN a0sym = 'fn*' THEN
RETURN types.malfunc(M, types.nth(M, ast, 2),
types.nth(M, ast, 1),
env);
ELSE
el := eval_ast(ast, env);
f := types.first(M, el);
args := TREAT(M(types.slice(M, el, 1)) AS mal_seq_T).val_seq;
IF M(f).type_id = 12 THEN
malfn := TREAT(M(f) AS mal_func_T);
env := env_pkg.env_new(M, E, malfn.env,
malfn.params, args);
ast := malfn.ast; -- TCO
ELSE
RETURN do_builtin(f, args);
END IF;
END CASE;
END LOOP;
END;
-- hack to get around lack of function references
-- functions that require special access to repl_env or EVAL
-- are implemented directly here, otherwise, core.do_core_fn
-- is called.
FUNCTION do_builtin(fn integer, args mal_vals) RETURN integer IS
fname varchar2(100);
val integer;
f integer;
malfn mal_func_T;
fargs mal_vals;
fn_env integer;
BEGIN
fname := TREAT(M(fn) AS mal_str_T).val_str;
CASE
WHEN fname = 'do_eval' THEN
RETURN EVAL(args(1), repl_env);
WHEN fname = 'swap!' THEN
val := TREAT(M(args(1)) AS mal_atom_T).val;
f := args(2);
-- slice one extra at the beginning that will be changed
-- to the value of the atom
fargs := TREAT(M(types.slice(M, args, 1)) AS mal_seq_T).val_seq;
fargs(1) := val;
IF M(f).type_id = 12 THEN
malfn := TREAT(M(f) AS mal_func_T);
fn_env := env_pkg.env_new(M, E, malfn.env,
malfn.params, fargs);
val := EVAL(malfn.ast, fn_env);
ELSE
val := do_builtin(f, fargs);
END IF;
RETURN types.atom_reset(M, args(1), val);
ELSE
RETURN core.do_core_func(M, H, fn, args);
END CASE;
END;
-- print
FUNCTION PRINT(exp integer) RETURN varchar IS
BEGIN
RETURN printer.pr_str(M, H, exp);
END;
-- repl
FUNCTION REP(line varchar) RETURN varchar IS
BEGIN
RETURN PRINT(EVAL(READ(line), repl_env));
END;
BEGIN
-- initialize memory pools
M := types.mem_new();
H := types.map_entry_table();
E := env_pkg.env_entry_table();
repl_env := env_pkg.env_new(M, E, NULL);
argv := TREAT(M(reader.read_str(M, H, args)) AS mal_seq_T).val_seq;
-- core.EXT: defined using PL/SQL
core_ns := core.get_core_ns();
FOR cidx IN 1..core_ns.COUNT LOOP
x := env_pkg.env_set(M, E, repl_env,
types.symbol(M, core_ns(cidx)),
types.func(M, core_ns(cidx)));
END LOOP;
x := env_pkg.env_set(M, E, repl_env,
types.symbol(M, 'eval'),
types.func(M, 'do_eval'));
x := env_pkg.env_set(M, E, repl_env,
types.symbol(M, '*ARGV*'),
types.slice(M, argv, 1));
-- core.mal: defined using the language itself
line := REP('(def! not (fn* (a) (if a false true)))');
line := REP('(def! load-file (fn* (f) (eval (read-string (str "(do " (slurp f) ")")))))');
line := REP('(defmacro! cond (fn* (& xs) (if (> (count xs) 0) (list ''if (first xs) (if (> (count xs) 1) (nth xs 1) (throw "odd number of forms to cond")) (cons ''cond (rest (rest xs)))))))');
line := REP('(defmacro! or (fn* (& xs) (if (empty? xs) nil (if (= 1 (count xs)) (first xs) `(let* (or_FIXME ~(first xs)) (if or_FIXME or_FIXME (or ~@(rest xs))))))))');
IF argv.COUNT() > 0 THEN
BEGIN
line := REP('(load-file "' ||
TREAT(M(argv(1)) AS mal_str_T).val_str ||
'")');
io.close(1); -- close output stream
RETURN 0;
EXCEPTION WHEN OTHERS THEN
io.writeline('Error: ' || SQLERRM);
io.writeline(dbms_utility.format_error_backtrace);
io.close(1); -- close output stream
RAISE;
END;
END IF;
WHILE true LOOP
BEGIN
line := io.readline('user> ', 0);
IF line = EMPTY_CLOB() THEN CONTINUE; END IF;
IF line IS NOT NULL THEN
io.writeline(REP(line));
END IF;
EXCEPTION WHEN OTHERS THEN
IF SQLCODE = -20001 THEN -- io read stream closed
io.close(1); -- close output stream
RETURN 0;
END IF;
io.writeline('Error: ' || SQLERRM);
io.writeline(dbms_utility.format_error_backtrace);
END;
END LOOP;
END;
END mal;
/
show errors;
quit;