From 78d5b45b0caa16fa98ccd61c3ecb364ceac0b0c6 Mon Sep 17 00:00:00 2001
From: Snider <snider@host.uk.com>
Date: Mon, 23 Feb 2026 05:11:04 +0000
Subject: [PATCH] =?UTF-8?q?feat:=20modernise=20to=20Go=201.26=20=E2=80=94?=
 =?UTF-8?q?=20iterators,=20slices/maps,=20EachSeq?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- Add EachSeq[T](iter.Seq[T], fn) for iterator-based template rendering
- Use slices.Collect(maps.Keys()) + slices.Sort for deterministic attr output
- Use strings.SplitSeq in codegen TagToClassName and path parsing
- Use range over int in layout and pipeline loops
- Refresh go.sum

Co-Authored-By: Gemini <noreply@google.com>
Co-Authored-By: Virgil <virgil@lethean.io>
---
 codegen/codegen.go |  3 +--
 go.sum             | 15 +++++++++++++++
 layout.go          |  2 +-
 node.go            | 27 ++++++++++++++-------------
 path.go            |  9 +++++----
 pipeline.go        |  2 +-
 6 files changed, 37 insertions(+), 21 deletions(-)

diff --git a/codegen/codegen.go b/codegen/codegen.go
index 6e60783..8c443cf 100644
--- a/codegen/codegen.go
+++ b/codegen/codegen.go
@@ -54,9 +54,8 @@ func GenerateRegistration(tag, className string) string {
 
 // TagToClassName converts a kebab-case tag to PascalCase class name.
 func TagToClassName(tag string) string {
-	parts := strings.Split(tag, "-")
 	var b strings.Builder
-	for _, p := range parts {
+	for p := range strings.SplitSeq(tag, "-") {
 		if len(p) > 0 {
 			b.WriteString(strings.ToUpper(p[:1]))
 			b.WriteString(p[1:])
diff --git a/go.sum b/go.sum
index 9ebd72f..53e527f 100644
--- a/go.sum
+++ b/go.sum
@@ -1,14 +1,29 @@
 forge.lthn.ai/core/go-i18n v0.0.1 h1:7I2cOv3GCc7MssLny/CAnwz3L7/Y4iqwzrCRQMQ+teA=
+forge.lthn.ai/core/go-i18n v0.0.1/go.mod h1:nyiGwZ3jV4h9Yge6mSrKVTo7CI1LI/p3ydI+9jUnMtk=
 forge.lthn.ai/core/go-inference v0.0.1 h1:hf5eOzm5sNDifhb0BscMTyKEkB44r2Tv58wakHGvtz4=
+forge.lthn.ai/core/go-inference v0.0.1/go.mod h1:pq2JCmbWLHgik0QdAflGb3raJcCGC44xt8rCUtDjFys=
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
+github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
+github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=
+github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7so1lCWt35ZSgc=
 github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 golang.org/x/text v0.34.0 h1:oL/Qq0Kdaqxa1KbNeMKwQq0reLCCaFtqu2eNuSeNHbk=
+golang.org/x/text v0.34.0/go.mod h1:homfLqTYRFyVYemLBFl5GgL/DWEiH5wcsQ5gSh1yziA=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/layout.go b/layout.go
index 3a3426c..00890d1 100644
--- a/layout.go
+++ b/layout.go
@@ -74,7 +74,7 @@ func (l *Layout) blockID(slot byte) string {
 func (l *Layout) Render(ctx *Context) string {
 	var b strings.Builder
 
-	for i := 0; i < len(l.variant); i++ {
+	for i := range len(l.variant) {
 		slot := l.variant[i]
 		children := l.slots[slot]
 		if len(children) == 0 {
diff --git a/node.go b/node.go
index ee72d9a..71823c3 100644
--- a/node.go
+++ b/node.go
@@ -1,7 +1,9 @@
 package html
 
 import (
-	"sort"
+	"iter"
+	"maps"
+	"slices"
 	"strings"
 
 	i18n "forge.lthn.ai/core/go-i18n"
@@ -87,11 +89,8 @@ func (n *elNode) Render(ctx *Context) string {
 	b.WriteString(n.tag)
 
 	// Sort attribute keys for deterministic output.
-	keys := make([]string, 0, len(n.attrs))
-	for k := range n.attrs {
-		keys = append(keys, k)
-	}
-	sort.Strings(keys)
+	keys := slices.Collect(maps.Keys(n.attrs))
+	slices.Sort(keys)
 	for _, key := range keys {
 		b.WriteByte(' ')
 		b.WriteString(key)
@@ -106,8 +105,8 @@ func (n *elNode) Render(ctx *Context) string {
 		return b.String()
 	}
 
-	for _, child := range n.children {
-		b.WriteString(child.Render(ctx))
+	for i := range len(n.children) {
+		b.WriteString(n.children[i].Render(ctx))
 	}
 
 	b.WriteString("</")
@@ -233,21 +232,23 @@ func (n *switchNode) Render(ctx *Context) string {
 // --- eachNode ---
 
 type eachNode[T any] struct {
-	items []T
+	items iter.Seq[T]
 	fn    func(T) Node
 }
 
 // Each iterates items and renders each via fn.
 func Each[T any](items []T, fn func(T) Node) Node {
+	return EachSeq(slices.Values(items), fn)
+}
+
+// EachSeq iterates an iter.Seq and renders each via fn.
+func EachSeq[T any](items iter.Seq[T], fn func(T) Node) Node {
 	return &eachNode[T]{items: items, fn: fn}
 }
 
 func (n *eachNode[T]) Render(ctx *Context) string {
-	if len(n.items) == 0 {
-		return ""
-	}
 	var b strings.Builder
-	for _, item := range n.items {
+	for item := range n.items {
 		b.WriteString(n.fn(item).Render(ctx))
 	}
 	return b.String()
diff --git a/path.go b/path.go
index 0bad936..e33307b 100644
--- a/path.go
+++ b/path.go
@@ -11,12 +11,13 @@ func ParseBlockID(id string) []byte {
 
 	// Split on "-" and take every other element (the slot letters).
 	// Format: "X-0" or "X-0-Y-0-Z-0"
-	parts := strings.Split(id, "-")
 	var slots []byte
-	for i := 0; i < len(parts); i += 2 {
-		if len(parts[i]) == 1 {
-			slots = append(slots, parts[i][0])
+	i := 0
+	for part := range strings.SplitSeq(id, "-") {
+		if i%2 == 0 && len(part) == 1 {
+			slots = append(slots, part[0])
 		}
+		i++
 	}
 	return slots
 }
diff --git a/pipeline.go b/pipeline.go
index 55b8c36..0fcdcb4 100644
--- a/pipeline.go
+++ b/pipeline.go
@@ -75,7 +75,7 @@ func CompareVariants(r *Responsive, ctx *Context) map[string]float64 {
 	}
 
 	scores := make(map[string]float64)
-	for i := 0; i < len(imprints); i++ {
+	for i := range len(imprints) {
 		for j := i + 1; j < len(imprints); j++ {
 			key := imprints[i].name + ":" + imprints[j].name
 			scores[key] = imprints[i].imp.Similar(imprints[j].imp)