From 59e3a7d2c8cafec5105e4a04a009f6521ab39598 Mon Sep 17 00:00:00 2001
From: Arpad Ryszka <arpio@squareroundforest.org>
Date: Fri, 12 Sep 2025 01:58:50 +0200
Subject: [PATCH] wip

---
 lib.go      | 32 ++++++++++++++++++++++++++++----
 lib_test.go |  9 +++++----
 notes.txt   |  5 +++++
 3 files changed, 38 insertions(+), 8 deletions(-)

diff --git a/lib.go b/lib.go
index e6f40e1..1afee05 100644
--- a/lib.go
+++ b/lib.go
@@ -164,6 +164,10 @@ func ScriptContent(t Tag) Tag {
 	return t()(renderGuide{script: true})
 }
 
+func InlineChildren(t Tag) Tag {
+	return t
+}
+
 // inline tags are not broken into separate lines when rendering with indentation
 // deprecated in HTML, but only used for indentation
 func Inline(t Tag) Tag {
@@ -210,11 +214,31 @@ func FromTemplate[Data any](f Template[Data]) Tag {
 }
 
 // in the functional programming sense
-func Map(data []any, tag Tag) []Tag {
-	var tags []Tag
+func Map[Data any](data []Data, tag Tag, tags ...Tag) []Tag {
+	var ret []Tag
 	for _, d := range data {
-		tags = append(tags, tag(d))
+		var retd Tag
+		for i := len(tags) - 1; i >= 0; i-- {
+			retd = tags[i](d)
+		}
+
+		if retd == nil {
+			retd = tag(d)
+			continue
+		}
+
+		retd = tag(retd)
 	}
 
-	return tags
+	return ret
+}
+
+func MapChildren[Data any](data []Data, tag Tag, tags ...Tag) []any {
+	var a []any
+	c := Map(data, tag, tags...)
+	for _, ci := range c {
+		a = append(a, ci)
+	}
+
+	return a
 }
diff --git a/lib_test.go b/lib_test.go
index 23a52c8..b5df03a 100644
--- a/lib_test.go
+++ b/lib_test.go
@@ -4,6 +4,7 @@ import (
 	"code.squareroundforest.org/arpio/html"
 	. "code.squareroundforest.org/arpio/html/tags"
 	"testing"
+	"bytes"
 )
 
 func TestLib(t *testing.T) {
@@ -22,7 +23,7 @@ func TestLib(t *testing.T) {
 		)
 
 		memberHTML := html.FromTemplate(
-			func(m member) Tag {
+			func(m member) html.Tag {
 				return Li(
 					Div("Name: ", m.name),
 					Div("Level: ", m.level),
@@ -31,11 +32,11 @@ func TestLib(t *testing.T) {
 		)
 
 		teamHTML := html.FromTemplate(
-			func(t team) Tag {
+			func(t team) html.Tag {
 				return Div(
 					H3(t.name),
 					P("Rank: ", t.rank),
-					Ul(html.Map(t.members, memberHTML)...),
+					Ul(html.MapChildren(t.members, memberHTML)...),
 				)
 			},
 		)
@@ -56,7 +57,7 @@ func TestLib(t *testing.T) {
 		}
 
 		var b bytes.Buffer
-		if html.RenderIndent(&b, "\t", 0, teamHTML(myTeam)); err != nil {
+		if err := html.RenderIndent(&b, "\t", 0, teamHTML(myTeam)); err != nil {
 			t.Fatal(err)
 		}
 
diff --git a/notes.txt b/notes.txt
index 1c44364..7b4e7b9 100644
--- a/notes.txt
+++ b/notes.txt
@@ -3,3 +3,8 @@ like <br>: inline void
 inline <hr>: block void
 like script: no escaping
 split the validation from the rendering
+take copies of the children to ensure immutability
+explain the immutability guarantee in the Go docs: for children yes, for children references no. The general
+recommendation is not to mutate children. Ofc, creatively breaking the rules is always well appreciated by the
+right audience
+test wrapped templates