Use unwrap in some io functions

docs/builtins.md

@@ -118,6 +118,22 @@ Splits a list into two lists at the first occurrence of a value.
 List/split_once(xs: List(T), val: T) -> (Result(List(T), List(T)))
 ```
 
+## Result
+
+```python
+type Result<A, B>:
+  Ok { val: A }
+  Err { val: B }
+```
+
+### Result/unwrap
+
+Returns the inner value of `Result/Ok` or `Result/Err`.
+
+```python
+def Result/unwrap(result: Result<A, B>): A || B
+```
+
 ## Tree
 
 ```python
@@ -527,21 +543,23 @@ def IO/DyLib/open(path: String, lazy: u24) -> u24
 ```
 
 Loads a dynamic library file.
-* `path` is the path to the library file.
-* `lazy` is a boolean encoded as a `u24` that determines if all functions are loaded lazily (`1`) or upfront (`0`).
-* Returns an unique id to the library object encoded as a `u24`.
+
+- `path` is the path to the library file.
+- `lazy` is a boolean encoded as a `u24` that determines if all functions are loaded lazily (`1`) or upfront (`0`).
+- Returns an unique id to the library object encoded as a `u24`.
 
 #### IO/DyLib/call
 
-``` py
+```py
 def IO/DyLib/call(dl: u24, fn: String, args: Any) -> Any
 ```
 
 Calls a function of a previously opened library.
-* `dl` is the id of the library object.
-* `fn` is the name of the function in the library.
-* `args` are the arguments to the function. The expected values depend on the called function.
-* The returned value is determined by the called function.
+
+- `dl` is the id of the library object.
+- `fn` is the name of the function in the library.
+- `args` are the arguments to the function. The expected values depend on the called function.
+- The returned value is determined by the called function.
 
 #### IO/DyLib/close
 
@@ -550,8 +568,9 @@ def IO/DyLib/close(dl: u24) -> None
 ```
 
 Closes a previously open library.
-* `dl` is the id of the library object.
-* Returns nothing (`*`).  
+
+- `dl` is the id of the library object.
+- Returns nothing (`*`).
 
 ## Native number casting
 
@@ -585,7 +604,7 @@ Casts any native number to an i24.
 
 ```py
 def String/decode_utf8(bytes: [u24]) -> String
-``` 
+```
 
 Decodes a sequence of bytes to a String using utf-8 encoding.
 
@@ -647,7 +666,6 @@ Computes the arctangent of `y / x`.
 
 Has the same behaviour as `atan2f` in the C math lib.
 
-
 ### Math/PI
 
 Defines the Pi constant.
@@ -781,4 +799,4 @@ def Math/round(n: f24) -> f24
 You can force a function call to be evaluated lazily by wrapping it in a lazy thunk.
 In Bend, this can be expressed as `lambda x: x(my_function, arg1, arg2, ...)`.
 
-To evaluate the thunk, you can use the `undefer` function or apply `lambda x: x` to it.
+To evaluate the thunk, you can use the `undefer` function or apply `lambda x: x` to it.

src/fun/builtins.bend

@@ -92,6 +92,11 @@ type Nat = (Succ ~pred) | (Zero)
 
 type Result = (Ok val) | (Err val)
 
+Result/unwrap res = match res {
+  Result/Ok: res.val;
+  Result/Err: res.val;
+}
+
 type Tree:
   Node { ~left, ~right }
   Leaf { value }
@@ -189,7 +194,10 @@ IO/done_on_err done = done
 
 ## Time and sleep
 # Returns a monotonically increasing nanosecond timestamp as an u48 encoded as a pair of u24s.
-IO/get_time = (IO/Call IO/MAGIC "GET_TIME" * @x (IO/Done IO/MAGIC x))
+IO/get_time = with IO {
+    ask res = (IO/Call IO/MAGIC "GET_TIME" * @x (IO/Done IO/MAGIC x))
+    (wrap (Result/unwrap res))
+  }
 
 # Sleeps for the given number of nanoseconds, given by an u48 encoded as a pair of u24s.
 IO/nanosleep hi_lo = (IO/Call IO/MAGIC "SLEEP" hi_lo @x (IO/Done IO/MAGIC x))
@@ -199,7 +207,9 @@ def IO/sleep(seconds):
   nanos = seconds * 1_000_000_000.0
   lo = to_u24(nanos % 0x1_000_000.0)
   hi = to_u24(nanos / 0x1_000_000.0)
-  return IO/nanosleep((hi, lo))
+  with IO:
+    res <- IO/nanosleep((hi, lo))
+    return wrap(Result/unwrap(res))
 
 ## File IO
 
@@ -296,7 +306,10 @@ def IO/FS/write_file(path, bytes):
 
 # IO/print(text: String) -> (IO *)
 # Prints a string to stdout, encoding it with utf-8.
-IO/print text = (IO/FS/write IO/FS/STDOUT (String/encode_utf8 text))
+IO/print text = with IO {
+    ask res = (IO/FS/write IO/FS/STDOUT (String/encode_utf8 text))
+    (wrap (Result/unwrap res))
+  }
 
 # IO/input() -> IO String
 # Read characters from stdin until a newline is found.