1 files changed, 22 insertions, 8 deletions
diff --git a/lib/std/private/globs.nim b/lib/std/private/globs.nim
index b98a7808b..a6d088558 100644
--- a/lib/std/private/globs.nim
+++ b/lib/std/private/globs.nim
@@ -4,9 +4,18 @@ this can eventually be moved to std/os and `walkDirRec` can be implemented in te
 to avoid duplication
 ]##
 
-import std/[os]
+import std/os
 when defined(windows):
-  from strutils import replace
+  from std/strutils import replace
+
+when defined(nimPreviewSlimSystem):
+  import std/[assertions, objectdollar]
+
+
+when defined(nimHasEffectsOf):
+  {.experimental: "strictEffects".}
+else:
+  {.pragma: effectsOf.}
 
 type
   PathEntry* = object
@@ -14,7 +23,7 @@ type
     path*: string
 
 iterator walkDirRecFilter*(dir: string, follow: proc(entry: PathEntry): bool = nil,
-    relative = false, checkDir = true): PathEntry {.tags: [ReadDirEffect].} =
+    relative = false, checkDir = true): PathEntry {.tags: [ReadDirEffect], effectsOf: follow.} =
   ## Improved `os.walkDirRec`.
   #[
   note: a yieldFilter isn't needed because caller can filter at call site, without
@@ -45,12 +54,17 @@ iterator walkDirRecFilter*(dir: string, follow: proc(entry: PathEntry): bool = n
 
 proc nativeToUnixPath*(path: string): string =
   # pending https://github.com/nim-lang/Nim/pull/13265
-  doAssert not path.isAbsolute # not implemented here; absolute files need more care for the drive
+  result = path
+  when defined(windows):
+    if path.len >= 2 and path[0] in {'a'..'z', 'A'..'Z'} and path[1] == ':':
+      result[0] = '/'
+      result[1] = path[0]
+      if path.len > 2 and path[2] != '\\':
+        raiseAssert "paths like `C:foo` are currently unsupported, path: " & path
   when DirSep == '\\':
-    result = replace(path, '\\', '/')
-  else: result = path
+    result = replace(result, '\\', '/')
 
 when isMainModule:
-  import sugar
-  for a in walkDirRecFilter(".", follow = a=>a.path.lastPathPart notin ["nimcache", ".git", ".csources", "bin"]):
+  import std/sugar
+  for a in walkDirRecFilter(".", follow = a=>a.path.lastPathPart notin ["nimcache", ".git", "csources_v1", "csources", "bin"]):
     echo a