Teach chk about Result

stew/errorhandling.nim

@@ -2,6 +2,9 @@ import
   typetraits, strutils,
   shims/macros, results
 
+export
+  results
+
 const
   enforce_error_handling {.strdefine.}: string = "yes"
   errorHandlingEnforced = parseBool(enforce_error_handling)
@@ -152,7 +155,13 @@ template raising*[E, R](x: Raising[E, R]): R =
   ## by the `errors` pragma.
   distinctBase(x)
 
-macro chk*[R, E](x: Raising[R, E], handlers: untyped): untyped =
+template raising*[R, E](x: Result[R, E]): R =
+  tryGet(x)
+
+macro chk*(x: Result, handlers): untyped =
+  discard
+
+macro chk*(x: Raising, handlers: untyped): untyped =
   ## The `chk` macro can be used in 2 different ways
   ##
   ## 1) Try to get the result of an expression. In case of any

tests/test_errorhandling.nim

@@ -7,6 +7,18 @@ proc bar(x: int): int {.noerrors.} =
 proc toString(x: int): string {.errors: (ValueError, KeyError, OSError).} =
   $x
 
+enum
+  ReadStatus = enum
+    FileNotFound
+    AccessDenied
+    HardwareError
+
+proc readFromDevice(path: string): Result[seq[byte], ReadStatus] =
+  err AccessDenied
+
+proc getGpsCoordinates(): Result[(float, float), cstring] =
+  ok (1.2, 3.4)
+
 proc main =
   let
     a = bar(10)
@@ -16,6 +28,13 @@ proc main =
             KeyError as err: err.msg
             OSError: raise
 
+    d = chk(readFromDevice("test"), @[1.byte, 2, 3])
+    
+    e = chk readFromDevice("test"):
+            FileNotFound: raise newException()
+            HardwareError: quit 1
+            else: @[]
+
   echo a
   echo b
   echo c