Merge pull request #1821 from arturo-lang/add-safe-get-set-overrides-…

…for-objects Add safe `get`/`set` overrides for custom types
arturo-lang · Dec 7, 2024 · dbbd13a · dbbd13a
2 parents fd8d8dc + 82f01e8
commit dbbd13a
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Showing 2 changed files with 26 additions and 6 deletions.
diff --git a/src/library/Collections.nim b/src/library/Collections.nim
@@ -696,7 +696,9 @@ proc defineLibrary*() =
             "collection": {String, Block, Range, Dictionary, Object, Store, Date, Binary, Bytecode, Complex, Error, ErrorKind},
             "index"     : {Any}
         },
-        attrs       = NoAttrs,
+        attrs       = {
+            "safe"  : ({Logical}, "get value, overriding potential magic methods (only for Object values)")
+        },
         returns     = {Any},
         example     = """
             user: #[
@@ -730,6 +732,13 @@ proc defineLibrary*() =
             print a\real                  ; 1.0
             print a\imaginary             ; 2.0
             print a\1                     ; 2.0
+            ..........
+            define :person [
+                get: method [what][
+                    (key? this what)? -> get.safe this what     ; if the key exists, return the value
+                                      -> "DEFAULT"              ; otherwise, do something else
+                ]
+            ]
         """:
             #=======================================================
             case xKind:
@@ -806,14 +815,14 @@ proc defineLibrary*() =
                         of String, Word, Literal:
                             if (let got = GetObjectKey(x, y.s, withError=false); not got.isNil):
                                 push(got)
-                            elif x.magic.fetch(GetM):
+                            elif x.magic.fetch(GetM) and (not hadAttr("safe")):
                                 mgk(@[x, y]) # value already pushed
                             else:
                                 discard GetObjectKey(x, y.s) # Merely to trigger the error
                         else:
                             if (let got = GetObjectKey(x, $(y), withError=false); not got.isNil):
                                 push(got)
-                            elif x.magic.fetch(GetM):
+                            elif x.magic.fetch(GetM) and (not hadAttr("safe")):
                                 mgk(@[x, y]) # value already pushed
                             else:
                                 discard GetObjectKey(x, $(y)) # Merely to trigger the error
@@ -1725,7 +1734,9 @@ proc defineLibrary*() =
             "index"     : {Any},
             "value"     : {Any}
         },
-        attrs       = NoAttrs,
+        attrs       = {
+            "safe"  : ({Logical}, "set value, overriding potential magic methods (only for Object values)")
+        },
         returns     = {Nothing},
         example     = """
             myDict: #[
@@ -1747,6 +1758,15 @@ proc defineLibrary*() =
             str\0: `x`
             print str
             ; xello
+            ..........
+            define :person [
+                set: method [what, value][
+                    ; do some processing...
+
+                    set.safe this what value
+                    ; and actually set the value internally
+                ]
+            ]
         """:
             #=======================================================
             case xKind:
@@ -1799,7 +1819,7 @@ proc defineLibrary*() =
                 of Object:
                     if unlikely(x.magic.fetch(ChangingM)):
                         mgk(@[x, y])
-                    if (x.magic.fetch(SetM) and (y.kind in {String,Word,Literal,Label}) and (y.s notin toSeq(x.proto.fields.keys()))):
+                    if (x.magic.fetch(SetM) and (not hadAttr("safe")) and (y.kind in {String,Word,Literal,Label}) and (y.s notin toSeq(x.proto.fields.keys()))):
                         mgk(@[x, y, z])
                     else:
                         case yKind:

diff --git a/version/build b/version/build
@@ -1 +1 @@
-3321
+3323