feat(range): rg.intersect

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Added
 - Enum can now have `rg`, `ud`, `void`, `pat` has value type
 - Object can have `const` properties (https://github.com/buzz-language/buzz/issues/13). A object with only `const` properties is considered itself `const`. Although we don't do anything yet with that concept. https://github.com/buzz-language/buzz/issues/114 is the objective but it requires being able to build objects and instances at compile time which is not yet possible.
+- `rg.subsetOf`, `rg.intersect`
 
 ## Modified
 

src/builtin/range.zig

@@ -85,3 +85,29 @@ pub fn subsetOf(ctx: *obj.NativeCtx) c_int {
 
     return 1;
 }
+
+pub fn intersect(ctx: *obj.NativeCtx) c_int {
+    const rangeA = ctx.vm.peek(1).obj().access(obj.ObjRange, .Range, ctx.vm.gc).?;
+    const rangeB = ctx.vm.peek(0).obj().access(obj.ObjRange, .Range, ctx.vm.gc).?;
+
+    ctx.vm.push(
+        Value.fromObj((ctx.vm.gc.allocateObject(
+            obj.ObjRange,
+            obj.ObjRange{
+                .high = @max(
+                    @min(rangeB.low, rangeB.high),
+                    @min(rangeA.low, rangeA.high),
+                ),
+                .low = @min(
+                    @max(rangeB.low, rangeB.high),
+                    @max(rangeA.low, rangeA.high),
+                ),
+            },
+        ) catch {
+            ctx.vm.panic("Out of memory");
+            unreachable;
+        }).toObj()),
+    );
+
+    return 1;
+}

src/obj.zig

@@ -2500,6 +2500,7 @@ pub const ObjRange = struct {
             .{ "len", buzz_builtin.range.len },
             .{ "invert", buzz_builtin.range.invert },
             .{ "subsetOf", buzz_builtin.range.subsetOf },
+            .{ "intersect", buzz_builtin.range.intersect },
         },
     );
 
@@ -2509,6 +2510,7 @@ pub const ObjRange = struct {
             .{ "len", "extern Function len() > int" },
             .{ "invert", "extern Function invert() > rg" },
             .{ "subsetOf", "extern Function subsetOf(rg other) > bool" },
+            .{ "intersect", "extern Function intersect(rg other) > rg" },
         },
     );