From 8daae270891e692c0e826f856b1a38df91e72171 Mon Sep 17 00:00:00 2001
From: Mark Spanbroek <mark@spanbroek.net>
Date: Wed, 7 Jun 2023 16:23:55 +0200
Subject: [PATCH] Do not edit AST nodes, make a copy first

Fixes error "typechecked nodes may not be modified"
---
 questionable/chaining.nim      | 4 ++++
 questionable/withoutresult.nim | 1 +
 2 files changed, 5 insertions(+)

diff --git a/questionable/chaining.nim b/questionable/chaining.nim
index e2c97cc..65ecaa2 100644
--- a/questionable/chaining.nim
+++ b/questionable/chaining.nim
@@ -22,23 +22,27 @@ template chain(option: typed, identifier: untyped{nkIdent}): untyped =
 
 macro chain(option: typed, infix: untyped{nkInfix}): untyped =
   # chain is of shape: option.?left `operator` right
+  let infix = infix.copyNimTree()
   let left = infix[1]
   infix[1] = quote do: `option`.?`left`
   infix
 
 macro chain(option: typed, bracket: untyped{nkBracketExpr}): untyped =
   # chain is of shape: option.?left[right]
+  let bracket = bracket.copyNimTree()
   let left = bracket[0]
   bracket[0] = quote do: `option`.?`left`
   bracket
 
 macro chain(option: typed, dot: untyped{nkDotExpr}): untyped =
   # chain is of shape: option.?left.right
+  let dot = dot.copyNimTree()
   let left = dot[0]
   dot[0] = quote do: `option`.?`left`
   dot
 
 macro chain(option: typed, call: untyped{nkCall}): untyped =
+  let call = call.copyNimTree()
   let procedure = call[0]
   if call.len == 1:
     # chain is of shape: option.?procedure()
diff --git a/questionable/withoutresult.nim b/questionable/withoutresult.nim
index cabba18..17cd333 100644
--- a/questionable/withoutresult.nim
+++ b/questionable/withoutresult.nim
@@ -12,6 +12,7 @@ proc undoSymbolResolution(expression, ident: NimNode): NimNode =
   if expression.kind in symbolKinds and eqIdent($expression, $ident):
     return ident
 
+  let expression = expression.copyNimTree()
   for i in 0..<expression.len:
     expression[i] = undoSymbolResolution(expression[i], ident)