return Result<T, E> from IO functions

examples/demo_io/main.bend

@@ -1,63 +1,35 @@
 test-io = 1
 
-type IO_T:
-  Done { magic, expr }
-  Call { magic, func, argm, cont }
+def unwrap(res):
+  match res:
+    case Result/Ok:
+      return res.val
+    case Result/Err:
+      return res.val
 
-def IO_T/MAGIC:
-  return (0xD0CA11, 0xFF1FF1)
+def open():
+  return call("OPEN", ("./LICENSE", "r"))
 
-def IO_T/bind(a, b):
-  match a:
-    case IO_T/Done:
-      return (undefer(b))(a.expr)
-    case IO_T/Call:
-      return IO_T/Call(IO_T/MAGIC, a.func, a.argm, lambda x: IO_T/bind(a.cont(x), b))
+def read(f):
+  return call("READ", (f, 47))
 
-def call_io(func, argm):
-  return IO_T/Call(IO_T/MAGIC, func, argm, lambda x: IO_T/Done(IO_T/MAGIC, x))
+def print(bytes):
+  with IO:
+    * <- call("WRITE", (1, bytes))
+    * <- call("WRITE", (1, "\n"))
 
-def read_input():
-  with IO_T:
-    * <- call_io("WRITE", (1, "What is your name?\n"))
-    return call_io("READ", (0, 10))
+    return wrap(*)
 
-def write_to_file():
-  with IO_T:
-    fp <- call_io("OPEN", ("testing.txt", "w"))
-    input <- read_input()
-    * <- call_io("WRITE", (fp, input))
-    * <- call_io("WRITE", (fp, "\n"))
-
-    return call_io("CLOSE", fp)
-
-def read_from_file():
-  with IO_T:
-    fp <- call_io("OPEN", ("testing.txt", "r"))
-    bytes <- call_io("READ", (fp, 5))
-    * <- call_io("WRITE", (1, bytes))
-    * <- call_io("SEEK", (fp, 2, 0))
-    bytes <- call_io("READ", (fp, 5))
-    * <- call_io("WRITE", (1, bytes))
-
-    return call_io("CLOSE", fp)
-
-def write:
-  return "WRITE"
-
-def one:
-  return 1
-
-def newline:
-  return "\n"
-
-def one_newline_pair:
-  return (one, newline)
+def close(f):
+  return call("CLOSE", f)
 
 def main():
-  with IO_T:
-    * <- write_to_file()
-    * <- read_from_file()
-    * <- call_io(write, one_newline_pair)
-
-    return 42
+  with IO:
+    f <- open()
+    f = unwrap(f)
+    bytes <- read(f)
+    bytes = unwrap(bytes)
+    * <- print(bytes)
+    res <- close(f)
+
+    return wrap(res)

examples/demo_io/main.hvm

@@ -1,23 +1,26 @@
-@IO_T/Call = (a (b (c (d ((@IO_T/Call/tag (a (b (c (d e))))) e)))))
+@IO/Call = (a (b (c (d ((@IO/Call/tag (a (b (c (d e))))) e)))))
 
-@IO_T/Call/tag = 1
+@IO/Call/tag = 1
 
-@IO_T/Done = (a (b ((@IO_T/Done/tag (a (b c))) c)))
+@IO/Done = (a (b ((@IO/Done/tag (a (b c))) c)))
 
-@IO_T/Done/tag = 0
+@IO/Done/tag = 0
 
-@IO_T/MAGIC = (13683217 16719857)
+@IO/MAGIC = (13683217 16719857)
 
-@IO_T/bind = ((@IO_T/bind__C2 a) a)
+@IO/bind = ((@IO/bind__C2 a) a)
 
-@IO_T/bind__C0 = (* (b (a c)))
+@IO/bind__C0 = (* (b (a c)))
   & @undefer ~ (a (b c))
 
-@IO_T/bind__C1 = (* (* (a (b ((c d) (e g))))))
-  & @IO_T/Call ~ (@IO_T/MAGIC (a (b ((c f) g))))
-  & @IO_T/bind ~ (d (e f))
+@IO/bind__C1 = (* (* (a (b ((c d) (e g))))))
+  & @IO/Call ~ (@IO/MAGIC (a (b ((c f) g))))
+  & @IO/bind ~ (d (e f))
 
-@IO_T/bind__C2 = (?((@IO_T/bind__C0 @IO_T/bind__C1) a) a)
+@IO/bind__C2 = (?((@IO/bind__C0 @IO/bind__C1) a) a)
+
+@IO/wrap = a
+  & @IO/Done ~ (@IO/MAGIC a)
 
 @String/Cons = (a (b ((@String/Cons/tag (a (b c))) c)))
 
@@ -27,215 +30,86 @@
 
 @String/Nil/tag = 0
 
-@call_io = (a (b c))
-  & @IO_T/Call ~ (@IO_T/MAGIC (a (b (@call_io__C0 c))))
-
-@call_io__C0 = a
-  & @IO_T/Done ~ (@IO_T/MAGIC a)
-
-@main = g
-  & @IO_T/bind ~ (@write_to_file ((((* e) f) f) g))
-  & @IO_T/bind ~ (@read_from_file ((((* c) d) d) e))
-  & @IO_T/bind ~ (a ((((* 42) b) b) c))
-  & @call_io ~ (@write (@one_newline_pair a))
-
-@newline = a
-  & @String/Cons ~ (10 (@String/Nil a))
-
-@one = 1
+@call = (a (b c))
+  & @IO/Call ~ (@IO/MAGIC (a (b (@call__C0 c))))
 
-@one_newline_pair = (@one @newline)
+@call__C0 = a
+  & @IO/Done ~ (@IO/MAGIC a)
 
-@read_from_file = a
-  & @IO_T/bind ~ (@read_from_file__C11 (@read_from_file__C10 a))
-
-@read_from_file__C0 = (f (* g))
-  & @call_io ~ (e (f g))
+@close = f
+  & @call ~ (e f)
   & @String/Cons ~ (67 (d e))
   & @String/Cons ~ (76 (c d))
   & @String/Cons ~ (79 (b c))
   & @String/Cons ~ (83 (a b))
   & @String/Cons ~ (69 (@String/Nil a))
 
-@read_from_file__C1 = e
-  & @String/Cons ~ (87 (d e))
-  & @String/Cons ~ (82 (c d))
-  & @String/Cons ~ (73 (b c))
-  & @String/Cons ~ (84 (a b))
-  & @String/Cons ~ (69 (@String/Nil a))
-
-@read_from_file__C10 = ((@read_from_file__C9 a) a)
-
-@read_from_file__C11 = q
-  & @call_io ~ (d ((o p) q))
+@main = w
+  & @IO/bind ~ (@open ((((s (a u)) (@IO/wrap v)) v) w))
+  & @IO/bind ~ (c ((((n (o (d q))) (r (s t))) t) u))
+  & @unwrap ~ (a {b r})
+  & @read ~ (b c)
+  & @IO/bind ~ (f ((((g (k (* m))) (n (o p))) p) q))
+  & @print ~ (e f)
+  & @unwrap ~ (d e)
+  & @IO/bind ~ (h ((((i i) (k l)) l) m))
+  & @close ~ (g h)
+
+@open = o
+  & @call ~ (d ((m n) o))
   & @String/Cons ~ (79 (c d))
   & @String/Cons ~ (80 (b c))
   & @String/Cons ~ (69 (a b))
   & @String/Cons ~ (78 (@String/Nil a))
-  & @String/Cons ~ (116 (n o))
-  & @String/Cons ~ (101 (m n))
-  & @String/Cons ~ (115 (l m))
-  & @String/Cons ~ (116 (k l))
-  & @String/Cons ~ (105 (j k))
-  & @String/Cons ~ (110 (i j))
-  & @String/Cons ~ (103 (h i))
-  & @String/Cons ~ (46 (g h))
-  & @String/Cons ~ (116 (f g))
-  & @String/Cons ~ (120 (e f))
-  & @String/Cons ~ (116 (@String/Nil e))
-  & @String/Cons ~ (114 (@String/Nil p))
-
-@read_from_file__C2 = (c (a e))
-  & @IO_T/bind ~ (b (((@read_from_file__C0 (c d)) d) e))
-  & @call_io ~ (@read_from_file__C1 ((1 a) b))
-
-@read_from_file__C3 = d
-  & @String/Cons ~ (82 (c d))
-  & @String/Cons ~ (69 (b c))
-  & @String/Cons ~ (65 (a b))
-  & @String/Cons ~ (68 (@String/Nil a))
-
-@read_from_file__C4 = ({a c} (* e))
-  & @IO_T/bind ~ (b (((@read_from_file__C2 (c d)) d) e))
-  & @call_io ~ (@read_from_file__C3 ((a 5) b))
-
-@read_from_file__C5 = d
-  & @String/Cons ~ (83 (c d))
-  & @String/Cons ~ (69 (b c))
-  & @String/Cons ~ (69 (a b))
-  & @String/Cons ~ (75 (@String/Nil a))
-
-@read_from_file__C6 = ({a c} (* e))
-  & @IO_T/bind ~ (b (((@read_from_file__C4 (c d)) d) e))
-  & @call_io ~ (@read_from_file__C5 ((a (2 0)) b))
-
-@read_from_file__C7 = e
+  & @String/Cons ~ (46 (l m))
+  & @String/Cons ~ (47 (k l))
+  & @String/Cons ~ (76 (j k))
+  & @String/Cons ~ (73 (i j))
+  & @String/Cons ~ (67 (h i))
+  & @String/Cons ~ (69 (g h))
+  & @String/Cons ~ (78 (f g))
+  & @String/Cons ~ (83 (e f))
+  & @String/Cons ~ (69 (@String/Nil e))
+  & @String/Cons ~ (114 (@String/Nil n))
+
+@print = (f h)
+  & @IO/bind ~ (g (@print__C3 h))
+  & @call ~ (e ((1 f) g))
   & @String/Cons ~ (87 (d e))
   & @String/Cons ~ (82 (c d))
   & @String/Cons ~ (73 (b c))
   & @String/Cons ~ (84 (a b))
   & @String/Cons ~ (69 (@String/Nil a))
 
-@read_from_file__C8 = (c (a e))
-  & @IO_T/bind ~ (b (((@read_from_file__C6 (c d)) d) e))
-  & @call_io ~ (@read_from_file__C7 ((1 a) b))
-
-@read_from_file__C9 = ({e g} i)
-  & @IO_T/bind ~ (f (((@read_from_file__C8 (g h)) h) i))
-  & @call_io ~ (d ((e 5) f))
-  & @String/Cons ~ (82 (c d))
-  & @String/Cons ~ (69 (b c))
-  & @String/Cons ~ (65 (a b))
-  & @String/Cons ~ (68 (@String/Nil a))
-
-@read_input = a
-  & @IO_T/bind ~ (@read_input__C2 (@read_input__C1 a))
+@print__C0 = ((* a) (* a))
 
-@read_input__C0 = (* e)
-  & @call_io ~ (d ((0 10) e))
-  & @String/Cons ~ (82 (c d))
-  & @String/Cons ~ (69 (b c))
-  & @String/Cons ~ (65 (a b))
-  & @String/Cons ~ (68 (@String/Nil a))
-
-@read_input__C1 = ((@read_input__C0 a) a)
-
-@read_input__C2 = y
-  & @call_io ~ (e ((1 x) y))
+@print__C1 = g
+  & @call ~ (e ((1 f) g))
   & @String/Cons ~ (87 (d e))
   & @String/Cons ~ (82 (c d))
   & @String/Cons ~ (73 (b c))
   & @String/Cons ~ (84 (a b))
   & @String/Cons ~ (69 (@String/Nil a))
-  & @String/Cons ~ (87 (w x))
-  & @String/Cons ~ (104 (v w))
-  & @String/Cons ~ (97 (u v))
-  & @String/Cons ~ (116 (t u))
-  & @String/Cons ~ (32 (s t))
-  & @String/Cons ~ (105 (r s))
-  & @String/Cons ~ (115 (q r))
-  & @String/Cons ~ (32 (p q))
-  & @String/Cons ~ (121 (o p))
-  & @String/Cons ~ (111 (n o))
-  & @String/Cons ~ (117 (m n))
-  & @String/Cons ~ (114 (l m))
-  & @String/Cons ~ (32 (k l))
-  & @String/Cons ~ (110 (j k))
-  & @String/Cons ~ (97 (i j))
-  & @String/Cons ~ (109 (h i))
-  & @String/Cons ~ (101 (g h))
-  & @String/Cons ~ (63 (f g))
   & @String/Cons ~ (10 (@String/Nil f))
 
-@test-io = 1
+@print__C2 = (a (* c))
+  & @IO/bind ~ (@print__C1 (((@print__C0 (a b)) b) c))
 
-@undefer = (((a a) b) b)
-
-@write = e
-  & @String/Cons ~ (87 (d e))
-  & @String/Cons ~ (82 (c d))
-  & @String/Cons ~ (73 (b c))
-  & @String/Cons ~ (84 (a b))
-  & @String/Cons ~ (69 (@String/Nil a))
-
-@write_to_file = a
-  & @IO_T/bind ~ (@write_to_file__C8 (@write_to_file__C7 a))
-
-@write_to_file__C0 = (f (* g))
-  & @call_io ~ (e (f g))
-  & @String/Cons ~ (67 (d e))
-  & @String/Cons ~ (76 (c d))
-  & @String/Cons ~ (79 (b c))
-  & @String/Cons ~ (83 (a b))
-  & @String/Cons ~ (69 (@String/Nil a))
+@print__C3 = ((@print__C2 (@IO/wrap a)) a)
 
-@write_to_file__C1 = a
-  & @String/Cons ~ (10 (@String/Nil a))
-
-@write_to_file__C2 = e
-  & @String/Cons ~ (87 (d e))
+@read = (e f)
+  & @call ~ (d ((e 47) f))
   & @String/Cons ~ (82 (c d))
-  & @String/Cons ~ (73 (b c))
-  & @String/Cons ~ (84 (a b))
-  & @String/Cons ~ (69 (@String/Nil a))
-
-@write_to_file__C3 = ({a c} (* e))
-  & @IO_T/bind ~ (b (((@write_to_file__C0 (c d)) d) e))
-  & @call_io ~ (@write_to_file__C2 ((a @write_to_file__C1) b))
-
-@write_to_file__C4 = e
-  & @String/Cons ~ (87 (d e))
-  & @String/Cons ~ (82 (c d))
-  & @String/Cons ~ (73 (b c))
-  & @String/Cons ~ (84 (a b))
-  & @String/Cons ~ (69 (@String/Nil a))
+  & @String/Cons ~ (69 (b c))
+  & @String/Cons ~ (65 (a b))
+  & @String/Cons ~ (68 (@String/Nil a))
 
-@write_to_file__C5 = ({a d} (b f))
-  & @IO_T/bind ~ (c (((@write_to_file__C3 (d e)) e) f))
-  & @call_io ~ (@write_to_file__C4 ((a b) c))
+@test-io = 1
 
-@write_to_file__C6 = (a c)
-  & @IO_T/bind ~ (@read_input (((@write_to_file__C5 (a b)) b) c))
+@undefer = (((a a) b) b)
 
-@write_to_file__C7 = ((@write_to_file__C6 a) a)
+@unwrap = ((@unwrap__C0 a) a)
 
-@write_to_file__C8 = q
-  & @call_io ~ (d ((o p) q))
-  & @String/Cons ~ (79 (c d))
-  & @String/Cons ~ (80 (b c))
-  & @String/Cons ~ (69 (a b))
-  & @String/Cons ~ (78 (@String/Nil a))
-  & @String/Cons ~ (116 (n o))
-  & @String/Cons ~ (101 (m n))
-  & @String/Cons ~ (115 (l m))
-  & @String/Cons ~ (116 (k l))
-  & @String/Cons ~ (105 (j k))
-  & @String/Cons ~ (110 (i j))
-  & @String/Cons ~ (103 (h i))
-  & @String/Cons ~ (46 (g h))
-  & @String/Cons ~ (116 (f g))
-  & @String/Cons ~ (120 (e f))
-  & @String/Cons ~ (116 (@String/Nil e))
-  & @String/Cons ~ (119 (@String/Nil p))
+@unwrap__C0 = (?(((a a) (* (b b))) c) c)