Fix for Nim 1.2.x

questionable/indexing.nim

@@ -1,29 +1,24 @@
 import std/macros
+import std/options
 
-macro `.?`*(expression: seq | string, brackets: untyped{nkBracket}): untyped =
-  # chain is of shape: (seq or string).?[index]
-  let index = brackets[0]
-  quote do:
-    block:
-      type T = typeof(`expression`[`index`])
-      let evaluated = `expression`
-      if `index` >= evaluated.low and `index` <= evaluated.high:
-        evaluated[`index`].some
-      else:
-        T.none
+proc safeGet[T](expression: seq[T] | openArray[T], index: int): Option[T] =
+  if index >= expression.low and index <= expression.high:
+    expression[index].some
+  else:
+    T.none
 
-macro `.?`*(expression: openArray, brackets: untyped{nkBracket}): untyped =
-  # chain is of shape: openArray.?[index]
-  let index = brackets[0]
-  quote do:
-    block:
-      type T = typeof(`expression`[`index`])
-      proc safeGet(arr: openArray[T], i: int): ?T {.gensym.} =
-        if i >= arr.low and i <= arr.high:
-          arr[i].some
-        else:
-          T.none
-      safeGet(`expression`, `index`)
+proc safeGet(expression: string, index: int): Option[char] =
+  if index >= expression.low and index <= expression.high:
+    expression[index].some
+  else:
+    char.none
+
+macro `.?`*(expression: seq | string | openArray, brackets: untyped{nkBracket}): untyped =
+    # chain is of shape: (seq or string or openArray).?[index]
+    let index = brackets[0]
+    quote do:
+      block:
+        safeGet(`expression`, `index`)
 
 macro `.?`*(expression: typed, brackets: untyped{nkBracket}): untyped =
   # chain is of shape: expression.?[index]