From 7b8e72ef07b2f60310ad6479c246f931e42dbfe9 Mon Sep 17 00:00:00 2001
From: Frederic Kehrein <frederic@kehrein.org>
Date: Fri, 11 Oct 2024 19:39:45 +0200
Subject: [PATCH] Adding for-in loop iteration over slices

---
 compiler/nflw.pas     | 28 ++++++++++++++++++++++++----
 tests/test/tslice1.pp | 18 ++++++++++++++++++
 tests/test/tslice2.pp | 19 +++++++++++++++++++
 3 files changed, 61 insertions(+), 4 deletions(-)
 create mode 100644 tests/test/tslice1.pp
 create mode 100644 tests/test/tslice2.pp

diff --git a/compiler/nflw.pas b/compiler/nflw.pas
index 65baefe07f..f29ec77b35 100644
--- a/compiler/nflw.pas
+++ b/compiler/nflw.pas
@@ -666,8 +666,18 @@ implementation
               end
             else
               begin
-                lowbound:=cinlinenode.create(in_low_x,false,ctemprefnode.create(arrayvar));
-                highbound:=cinlinenode.create(in_high_x,false,ctemprefnode.create(arrayvar));
+                { Iterating throug slice }
+                if (expression.nodetype=vecn) and (tvecnode(expression).right.nodetype=rangen) then
+                  begin
+                    lowbound:=trangenode(tvecnode(expression).right).left.getcopy;
+                    highbound:=trangenode(tvecnode(expression).right).right.getcopy;
+                    expression:=tvecnode(expression).left.getcopy;
+                  end
+                else
+                  begin
+                    lowbound:=cinlinenode.create(in_low_x,false,ctemprefnode.create(arrayvar));
+                    highbound:=cinlinenode.create(in_high_x,false,ctemprefnode.create(arrayvar));
+                  end;
               end;
 
             addstatement(loopstatement,arrayvar);
@@ -683,8 +693,18 @@ implementation
               end
             else
               begin
-                lowbound:=cinlinenode.create(in_low_x,false,expression.getcopy);
-                highbound:=cinlinenode.create(in_high_x,false,expression.getcopy);
+                { Iterating throug slice }
+                if (expression.nodetype=vecn) and (tvecnode(expression).right.nodetype=rangen) then
+                  begin
+                    lowbound:=trangenode(tvecnode(expression).right).left.getcopy;
+                    highbound:=trangenode(tvecnode(expression).right).right.getcopy;
+                    expression:=tvecnode(expression).left.getcopy;
+                  end
+                else
+                  begin
+                    lowbound:=cinlinenode.create(in_low_x,false,expression.getcopy);
+                    highbound:=cinlinenode.create(in_high_x,false,expression.getcopy);
+                  end;
               end;
           end;
 
diff --git a/tests/test/tslice1.pp b/tests/test/tslice1.pp
new file mode 100644
index 0000000000..eba85f7519
--- /dev/null
+++ b/tests/test/tslice1.pp
@@ -0,0 +1,18 @@
+program Test;
+
+{$Mode ObjFPC}{$H+}
+
+function sumafter1(arr: Array of Integer): Integer;
+var
+  i: Integer;
+begin
+  Result:=0;
+  for i in arr[1..High(arr)] do
+    Result:=Result+i;
+end;
+
+begin
+  if sumafter1([1,2,3,4]) <> 2+3+4 then
+    Halt(1);
+  WriteLn('ok');
+end.
diff --git a/tests/test/tslice2.pp b/tests/test/tslice2.pp
new file mode 100644
index 0000000000..84b121a766
--- /dev/null
+++ b/tests/test/tslice2.pp
@@ -0,0 +1,19 @@
+program Test;
+
+{$Mode ObjFPC}{$H+}
+
+type TIntArray = array of Integer;
+function sumafter1(arr: TIntArray): Integer;
+var
+  i: Integer;
+begin
+  Result:=0;
+  for i in arr[1..High(arr)] do
+    Result:=Result+i;
+end;
+
+begin
+  if sumafter1([1,2,3,4]) <> 2+3+4 then
+    Halt(1);
+  WriteLn('ok');
+end.