+++ /dev/null
--- ---------------------------------------------------------
--- stepA_mal.sql
-
-\i init.sql
-\i io.sql
-\i types.sql
-\i reader.sql
-\i printer.sql
-\i envs.sql
-\i core.sql
-
--- ---------------------------------------------------------
-
-CREATE SCHEMA mal;
-
--- read
-CREATE FUNCTION mal.READ(line varchar) RETURNS integer AS $$
-BEGIN
- RETURN reader.read_str(line);
-END; $$ LANGUAGE plpgsql;
-
--- eval
-CREATE FUNCTION mal.is_pair(ast integer) RETURNS boolean AS $$
-BEGIN
- RETURN types._sequential_Q(ast) AND types._count(ast) > 0;
-END; $$ LANGUAGE plpgsql;
-
-CREATE FUNCTION mal.quasiquote(ast integer) RETURNS integer AS $$
-DECLARE
- a0 integer;
- a00 integer;
-BEGIN
- IF NOT mal.is_pair(ast) THEN
- RETURN types._list(ARRAY[types._symbolv('quote'), ast]);
- ELSE
- a0 := types._nth(ast, 0);
- IF types._symbol_Q(a0) AND a0 = types._symbolv('unquote') THEN
- RETURN types._nth(ast, 1);
- ELSE
- a00 := types._nth(a0, 0);
- IF types._symbol_Q(a00) AND
- a00 = types._symbolv('splice-unquote') THEN
- RETURN types._list(ARRAY[types._symbolv('concat'),
- types._nth(a0, 1),
- mal.quasiquote(types._rest(ast))]);
- END IF;
- END IF;
- RETURN types._list(ARRAY[types._symbolv('cons'),
- mal.quasiquote(types._first(ast)),
- mal.quasiquote(types._rest(ast))]);
- END IF;
-END; $$ LANGUAGE plpgsql;
-
-CREATE FUNCTION mal.is_macro_call(ast integer, env integer) RETURNS boolean AS $$
-DECLARE
- a0 integer;
- f integer;
- result boolean = false;
-BEGIN
- IF types._list_Q(ast) THEN
- a0 = types._first(ast);
- IF types._symbol_Q(a0) AND
- envs.find(env, types._valueToString(a0)) IS NOT NULL THEN
- f := envs.get(env, a0);
- SELECT macro INTO result FROM types.value WHERE value_id = f;
- END IF;
- END IF;
- RETURN result;
-END; $$ LANGUAGE plpgsql;
-
-CREATE FUNCTION mal.macroexpand(ast integer, env integer) RETURNS integer AS $$
-DECLARE
- mac integer;
-BEGIN
- WHILE mal.is_macro_call(ast, env)
- LOOP
- mac := envs.get(env, types._first(ast));
- ast := types._apply(mac, types._valueToArray(types._rest(ast)));
- END LOOP;
- RETURN ast;
-END; $$ LANGUAGE plpgsql;
-
-CREATE FUNCTION mal.eval_ast(ast integer, env integer) RETURNS integer AS $$
-DECLARE
- type integer;
- seq integer[];
- eseq integer[];
- hash hstore;
- ehash hstore;
- kv RECORD;
- e integer;
- result integer;
-BEGIN
- SELECT type_id INTO type FROM types.value WHERE value_id = ast;
- CASE
- WHEN type = 7 THEN
- BEGIN
- result := envs.get(env, ast);
- END;
- WHEN type IN (8, 9) THEN
- BEGIN
- SELECT val_seq INTO seq FROM types.value WHERE value_id = ast;
- -- Evaluate each entry creating a new sequence
- FOR i IN 1 .. COALESCE(array_length(seq, 1), 0) LOOP
- eseq[i] := mal.EVAL(seq[i], env);
- END LOOP;
- INSERT INTO types.value (type_id, val_seq) VALUES (type, eseq)
- RETURNING value_id INTO result;
- END;
- WHEN type = 10 THEN
- BEGIN
- SELECT val_hash INTO hash FROM types.value WHERE value_id = ast;
- -- Evaluate each value for every key/value
- FOR kv IN SELECT * FROM each(hash) LOOP
- e := mal.EVAL(CAST(kv.value AS integer), env);
- IF ehash IS NULL THEN
- ehash := hstore(kv.key, CAST(e AS varchar));
- ELSE
- ehash := ehash || hstore(kv.key, CAST(e AS varchar));
- END IF;
- END LOOP;
- INSERT INTO types.value (type_id, val_hash) VALUES (type, ehash)
- RETURNING value_id INTO result;
- END;
- ELSE
- result := ast;
- END CASE;
-
- RETURN result;
-END; $$ LANGUAGE plpgsql;
-
-CREATE FUNCTION mal.EVAL(ast integer, env integer) RETURNS integer AS $$
-DECLARE
- type integer;
- a0 integer;
- a0sym varchar;
- a1 integer;
- a2 integer;
- let_env integer;
- idx integer;
- binds integer[];
- exprs integer[];
- el integer;
- fn integer;
- fname varchar;
- args integer[];
- cond integer;
- fast integer;
- fparams integer;
- fenv integer;
- result integer;
-BEGIN
- LOOP
- -- PERFORM writeline(format('EVAL: %s [%s]', pr_str(ast), ast));
- SELECT type_id INTO type FROM types.value WHERE value_id = ast;
- IF type <> 8 THEN
- RETURN mal.eval_ast(ast, env);
- END IF;
-
- ast := mal.macroexpand(ast, env);
- SELECT type_id INTO type FROM types.value WHERE value_id = ast;
- IF type <> 8 THEN
- RETURN mal.eval_ast(ast, env);
- END IF;
- IF types._count(ast) = 0 THEN
- RETURN ast;
- END IF;
-
- a0 := types._first(ast);
- IF types._symbol_Q(a0) THEN
- a0sym := (SELECT val_string FROM types.value WHERE value_id = a0);
- ELSE
- a0sym := '__<*fn*>__';
- END IF;
-
- CASE
- WHEN a0sym = 'def!' THEN
- BEGIN
- RETURN envs.set(env, types._nth(ast, 1),
- mal.EVAL(types._nth(ast, 2), env));
- END;
- WHEN a0sym = 'let*' THEN
- BEGIN
- let_env := envs.new(env);
- a1 := types._nth(ast, 1);
- binds := (SELECT val_seq FROM types.value WHERE value_id = a1);
- idx := 1;
- WHILE idx < array_length(binds, 1) LOOP
- PERFORM envs.set(let_env, binds[idx],
- mal.EVAL(binds[idx+1], let_env));
- idx := idx + 2;
- END LOOP;
- env := let_env;
- ast := types._nth(ast, 2);
- CONTINUE; -- TCO
- END;
- WHEN a0sym = 'quote' THEN
- BEGIN
- RETURN types._nth(ast, 1);
- END;
- WHEN a0sym = 'quasiquote' THEN
- BEGIN
- ast := mal.quasiquote(types._nth(ast, 1));
- CONTINUE; -- TCO
- END;
- WHEN a0sym = 'defmacro!' THEN
- BEGIN
- fn := mal.EVAL(types._nth(ast, 2), env);
- fn := types._macro(fn);
- RETURN envs.set(env, types._nth(ast, 1), fn);
- END;
- WHEN a0sym = 'macroexpand' THEN
- BEGIN
- RETURN mal.macroexpand(types._nth(ast, 1), env);
- END;
- WHEN a0sym = 'try*' THEN
- BEGIN
- BEGIN
- RETURN mal.EVAL(types._nth(ast, 1), env);
- EXCEPTION WHEN OTHERS THEN
- IF types._count(ast) >= 3 THEN
- a2 = types._nth(ast, 2);
- IF types._valueToString(types._nth(a2, 0)) = 'catch*' THEN
- binds := ARRAY[types._nth(a2, 1)];
- exprs := ARRAY[types._stringv(SQLERRM)];
- env := envs.new(env, types._list(binds), exprs);
- RETURN mal.EVAL(types._nth(a2, 2), env);
- END IF;
- END IF;
- RAISE;
- END;
- END;
- WHEN a0sym = 'do' THEN
- BEGIN
- PERFORM mal.eval_ast(types._slice(ast, 1, types._count(ast)-1), env);
- ast := types._nth(ast, types._count(ast)-1);
- CONTINUE; -- TCO
- END;
- WHEN a0sym = 'if' THEN
- BEGIN
- cond := mal.EVAL(types._nth(ast, 1), env);
- SELECT type_id INTO type FROM types.value WHERE value_id = cond;
- IF type = 0 OR type = 1 THEN -- nil or false
- IF types._count(ast) > 3 THEN
- ast := types._nth(ast, 3);
- CONTINUE; -- TCO
- ELSE
- RETURN 0; -- nil
- END IF;
- ELSE
- ast := types._nth(ast, 2);
- CONTINUE; -- TCO
- END IF;
- END;
- WHEN a0sym = 'fn*' THEN
- BEGIN
- RETURN types._malfunc(types._nth(ast, 2), types._nth(ast, 1), env);
- END;
- ELSE
- BEGIN
- el := mal.eval_ast(ast, env);
- SELECT type_id, val_string, ast_id, params_id, env_id
- INTO type, fname, fast, fparams, fenv
- FROM types.value WHERE value_id = types._first(el);
- args := types._restArray(el);
- IF type = 11 THEN
- EXECUTE format('SELECT %s($1);', fname)
- INTO result USING args;
- RETURN result;
- ELSIF type = 12 THEN
- env := envs.new(fenv, fparams, args);
- ast := fast;
- CONTINUE; -- TCO
- ELSE
- RAISE EXCEPTION 'Invalid function call';
- END IF;
- END;
- END CASE;
- END LOOP;
-END; $$ LANGUAGE plpgsql;
-
--- print
-CREATE FUNCTION mal.PRINT(exp integer) RETURNS varchar AS $$
-BEGIN
- RETURN printer.pr_str(exp);
-END; $$ LANGUAGE plpgsql;
-
-
--- repl
-
--- repl_env is environment 0
-
-CREATE FUNCTION mal.REP(line varchar) RETURNS varchar AS $$
-BEGIN
- RETURN mal.PRINT(mal.EVAL(mal.READ(line), 0));
-END; $$ LANGUAGE plpgsql;
-
--- core.sql: defined using SQL (in core.sql)
--- repl_env is created and populated with core functions in by core.sql
-CREATE FUNCTION mal.mal_eval(args integer[]) RETURNS integer AS $$
-BEGIN
- RETURN mal.EVAL(args[1], 0);
-END; $$ LANGUAGE plpgsql;
-INSERT INTO types.value (type_id, val_string) VALUES (11, 'mal.mal_eval');
-
-SELECT envs.vset(0, 'eval',
- (SELECT value_id FROM types.value
- WHERE val_string = 'mal.mal_eval')) \g '/dev/null'
--- *ARGV* values are set by RUN
-SELECT envs.vset(0, '*ARGV*', mal.READ('()')) \g '/dev/null'
-
-
--- core.mal: defined using the language itself
-SELECT mal.REP('(def! *host-language* "plpqsql")') \g '/dev/null'
-SELECT mal.REP('(def! not (fn* (a) (if a false true)))') \g '/dev/null'
-SELECT mal.REP('(def! load-file (fn* (f) (eval (read-string (str "(do " (slurp f) ")")))))') \g '/dev/null'
-SELECT mal.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)))))))') \g '/dev/null'
-SELECT mal.REP('(def! inc (fn* [x] (+ x 1)))') \g '/dev/null'
-SELECT mal.REP('(def! gensym (let* [counter (atom 0)] (fn* [] (symbol (str "G__" (swap! counter inc))))))') \g '/dev/null'
-SELECT mal.REP('(defmacro! or (fn* (& xs) (if (empty? xs) nil (if (= 1 (count xs)) (first xs) (let* (condvar (gensym)) `(let* (~condvar ~(first xs)) (if ~condvar ~condvar (or ~@(rest xs)))))))))') \g '/dev/null'
-
-CREATE FUNCTION mal.MAIN(pwd varchar, argstring varchar DEFAULT NULL)
- RETURNS integer AS $$
-DECLARE
- line varchar;
- output varchar;
- allargs integer;
-BEGIN
- PERFORM envs.vset(0, '*PWD*', types._stringv(pwd));
-
- IF argstring IS NOT NULL THEN
- allargs := mal.READ(argstring);
- PERFORM envs.vset(0, '*ARGV*', types._rest(allargs));
- PERFORM mal.REP('(load-file ' ||
- printer.pr_str(types._first(allargs)) || ')');
- PERFORM io.close(1);
- PERFORM io.wait_flushed(1);
- RETURN 0;
- END IF;
-
- PERFORM mal.REP('(println (str "Mal [" *host-language* "]"))');
- WHILE true
- LOOP
- BEGIN
- line := io.readline('user> ', 0);
- IF line IS NULL THEN
- PERFORM io.close(1);
- RETURN 0;
- END IF;
- IF line NOT IN ('', E'\n') THEN
- output := mal.REP(line);
- PERFORM io.writeline(output);
- END IF;
-
- EXCEPTION WHEN OTHERS THEN
- PERFORM io.writeline('Error: ' || SQLERRM);
- END;
- END LOOP;
-END; $$ LANGUAGE plpgsql;