From b3800b7dfb864396ac74dc20390e728bc0b2d88e Mon Sep 17 00:00:00 2001
From: Leon Hudak <33522493+leohhhn@users.noreply.github.com>
Date: Tue, 19 Nov 2024 04:07:16 -0600
Subject: [PATCH] feat(examples): mirror realm (#3156)

<!-- please provide a detailed description of the changes made in this
pull request. -->

## Description

Adds the mirror realm.

<details><summary>Contributors' checklist...</summary>

- [x] Added new tests, or not needed, or not feasible
- [x] Provided an example (e.g. screenshot) to aid review or the PR is
self-explanatory
- [x] Updated the official documentation or not needed
- [x] No breaking changes were made, or a `BREAKING CHANGE: xxx` message
was included in the description
- [x] Added references to related issues and PRs
- [x] Provided any useful hints for running manual tests
</details>
---
 examples/gno.land/r/demo/mirror/doc.gno    |  3 ++
 examples/gno.land/r/demo/mirror/gno.mod    |  3 ++
 examples/gno.land/r/demo/mirror/mirror.gno | 33 ++++++++++++++++++++++
 examples/gno.land/r/leon/home/gno.mod      |  1 +
 examples/gno.land/r/leon/home/home.gno     |  2 ++
 5 files changed, 42 insertions(+)
 create mode 100644 examples/gno.land/r/demo/mirror/doc.gno
 create mode 100644 examples/gno.land/r/demo/mirror/gno.mod
 create mode 100644 examples/gno.land/r/demo/mirror/mirror.gno

diff --git a/examples/gno.land/r/demo/mirror/doc.gno b/examples/gno.land/r/demo/mirror/doc.gno
new file mode 100644
index 00000000000..40fdbd5bc26
--- /dev/null
+++ b/examples/gno.land/r/demo/mirror/doc.gno
@@ -0,0 +1,3 @@
+// Package mirror demonstrates that users can pass realm functions
+// as arguments to other realms.
+package mirror
diff --git a/examples/gno.land/r/demo/mirror/gno.mod b/examples/gno.land/r/demo/mirror/gno.mod
new file mode 100644
index 00000000000..2bf27fd6916
--- /dev/null
+++ b/examples/gno.land/r/demo/mirror/gno.mod
@@ -0,0 +1,3 @@
+module gno.land/r/demo/mirror
+
+require gno.land/p/demo/avl v0.0.0-latest
diff --git a/examples/gno.land/r/demo/mirror/mirror.gno b/examples/gno.land/r/demo/mirror/mirror.gno
new file mode 100644
index 00000000000..770fddc4fda
--- /dev/null
+++ b/examples/gno.land/r/demo/mirror/mirror.gno
@@ -0,0 +1,33 @@
+package mirror
+
+import (
+	"gno.land/p/demo/avl"
+)
+
+var store avl.Tree
+
+func Register(pkgpath string, rndr func(string) string) {
+	if store.Has(pkgpath) {
+		return
+	}
+
+	if rndr == nil {
+		return
+	}
+
+	store.Set(pkgpath, rndr)
+}
+
+func Render(path string) string {
+	if raw, ok := store.Get(path); ok {
+		return raw.(func(string) string)("")
+	}
+
+	if store.Size() == 0 {
+		return "None are fair."
+	}
+
+	return "Mirror, mirror on the wall, which realm's the fairest of them all?"
+}
+
+// Credits to @jeronimoalbi
diff --git a/examples/gno.land/r/leon/home/gno.mod b/examples/gno.land/r/leon/home/gno.mod
index 4649cf4abe6..7288c176050 100644
--- a/examples/gno.land/r/leon/home/gno.mod
+++ b/examples/gno.land/r/leon/home/gno.mod
@@ -5,5 +5,6 @@ require (
 	gno.land/r/demo/art/gnoface v0.0.0-latest
 	gno.land/r/demo/art/millipede v0.0.0-latest
 	gno.land/r/demo/hof v0.0.0-latest
+	gno.land/r/demo/mirror v0.0.0-latest
 	gno.land/r/leon/config v0.0.0-latest
 )
diff --git a/examples/gno.land/r/leon/home/home.gno b/examples/gno.land/r/leon/home/home.gno
index aea8b43e9cd..632b3f14a62 100644
--- a/examples/gno.land/r/leon/home/home.gno
+++ b/examples/gno.land/r/leon/home/home.gno
@@ -9,6 +9,7 @@ import (
 	"gno.land/r/demo/art/gnoface"
 	"gno.land/r/demo/art/millipede"
 	"gno.land/r/demo/hof"
+	"gno.land/r/demo/mirror"
 	"gno.land/r/leon/config"
 )
 
@@ -34,6 +35,7 @@ TODO import r/gh
 	}
 
 	hof.Register()
+	mirror.Register(std.CurrentRealm().PkgPath(), Render)
 }
 
 func UpdatePFP(url, caption string) {