Add ssg package to registry

Static site generator utilities extracted from blu-site, providing
reusable post/tag types, content reading, date sorting, and file I/O.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/ssg/lib.lux

@@ -0,0 +1,207 @@
+// ssg - Static site generator utilities for Lux
+//
+// Provides reusable types and functions for building static sites:
+// - Post/TagEntry types for content modeling
+// - File reading and frontmatter parsing
+// - Date sorting and formatting
+// - Tag collection and filtering
+// - File I/O helpers
+
+import markdown
+import frontmatter
+import path
+
+// A parsed post: date, title, slug, tags (raw string), content (HTML)
+pub type Post = | Post(String, String, String, String, String)
+
+// A tag entry: tag name, post title, post date, post slug, section name
+pub type TagEntry = | TagEntry(String, String, String, String, String)
+
+// --- Post Accessors ---
+
+pub fn postDate(p: Post): String =
+    match p {
+    Post(d, _, _, _, _) => d,
+}
+
+pub fn postTitle(p: Post): String =
+    match p {
+    Post(_, t, _, _, _) => t,
+}
+
+pub fn postSlug(p: Post): String =
+    match p {
+    Post(_, _, s, _, _) => s,
+}
+
+pub fn postTags(p: Post): String =
+    match p {
+    Post(_, _, _, t, _) => t,
+}
+
+pub fn postContent(p: Post): String =
+    match p {
+    Post(_, _, _, _, c) => c,
+}
+
+pub fn postTagList(p: Post): List<String> = {
+    let raw = postTags(p)
+    if raw == "" then [] else String.split(raw, " ")
+}
+
+// --- TagEntry Accessors ---
+
+pub fn tagName(e: TagEntry): String =
+    match e {
+    TagEntry(t, _, _, _, _) => t,
+}
+
+pub fn tagTitle(e: TagEntry): String =
+    match e {
+    TagEntry(_, t, _, _, _) => t,
+}
+
+pub fn tagDate(e: TagEntry): String =
+    match e {
+    TagEntry(_, _, d, _, _) => d,
+}
+
+pub fn tagSlug(e: TagEntry): String =
+    match e {
+    TagEntry(_, _, _, s, _) => s,
+}
+
+pub fn tagSection(e: TagEntry): String =
+    match e {
+    TagEntry(_, _, _, _, s) => s,
+}
+
+// --- Slug / Filename ---
+
+pub fn slugFromFilename(filename: String): String = path.stripExtension(filename)
+
+// --- Date Formatting ---
+
+pub fn formatDate(isoDate: String): String = {
+    if String.length(isoDate) < 10 then isoDate else {
+    let year = String.substring(isoDate, 0, 4)
+    let month = String.substring(isoDate, 5, 7)
+    let day = String.substring(isoDate, 8, 10)
+    let monthName = if month == "01" then "Jan" else if month == "02" then "Feb" else if month == "03" then "Mar" else if month == "04" then "Apr" else if month == "05" then "May" else if month == "06" then "Jun" else if month == "07" then "Jul" else if month == "08" then "Aug" else if month == "09" then "Sep" else if month == "10" then "Oct" else if month == "11" then "Nov" else "Dec"
+    year + " " + monthName + " " + day
+}
+}
+
+// --- Sorting ---
+
+fn insertByDate(sorted: List<Post>, item: Post): List<Post> = {
+    match List.head(sorted) {
+    None => [item],
+    Some(first) => if postDate(item) >= postDate(first) then List.concat([item], sorted) else match List.tail(sorted) {
+    Some(rest) => List.concat([first], insertByDate(rest, item)),
+    None => [first, item],
+},
+}
+}
+
+fn sortInsert(sorted: List<Post>, item: Post): List<Post> = insertByDate(sorted, item)
+
+pub fn sortByDateDesc(items: List<Post>): List<Post> = List.fold(items, [], sortInsert)
+
+// --- Content Reading ---
+
+pub fn parseFile(filepath: String): Post with {File} = {
+    let raw = File.read(filepath)
+    let doc = frontmatter.parse(raw)
+    let title = frontmatter.title(doc)
+    let date = frontmatter.date(doc)
+    let tags = frontmatter.getOrDefault(doc, "tags", "")
+    let body = frontmatter.body(doc)
+    let htmlContent = markdown.toHtml(body)
+    let filename = path.basename(filepath)
+    let slug = slugFromFilename(filename)
+    Post(date, title, slug, tags, htmlContent)
+}
+
+fn mapParseFiles(dir: String, files: List<String>): List<Post> with {File} =
+    match List.head(files) {
+    None => [],
+    Some(filename) => {
+    let page = parseFile(dir + "/" + filename)
+    match List.tail(files) {
+    Some(rest) => List.concat([page], mapParseFiles(dir, rest)),
+    None => [page],
+}
+},
+}
+
+pub fn readSection(contentDir: String, section: String): List<Post> with {File} = {
+    let dir = contentDir + "/" + section
+    if File.exists(dir) then {
+    let entries = File.readDir(dir)
+    let mdFiles = List.filter(entries, fn(e: String): Bool => String.endsWith(e, ".md"))
+    mapParseFiles(dir, mdFiles)
+} else []
+}
+
+pub fn readAllSections(contentDir: String, sections: List<String>): List<Post> with {File} =
+    match List.head(sections) {
+    None => [],
+    Some(section) => {
+    let posts = readSection(contentDir, section)
+    match List.tail(sections) {
+    Some(rest) => List.concat(posts, readAllSections(contentDir, rest)),
+    None => posts,
+}
+},
+}
+
+// --- Tags ---
+
+fn collectTagsForPage(section: String, page: Post): List<TagEntry> = {
+    let tagsRaw = postTags(page)
+    let tags = if tagsRaw == "" then [] else String.split(tagsRaw, " ")
+    List.map(tags, fn(tag: String): TagEntry => TagEntry(tag, postTitle(page), postDate(page), postSlug(page), section))
+}
+
+pub fn collectTags(section: String, posts: List<Post>): List<TagEntry> = {
+    let nested = List.map(posts, fn(page: Post): List<TagEntry> => collectTagsForPage(section, page))
+    List.fold(nested, [], fn(acc: List<TagEntry>, entries: List<TagEntry>): List<TagEntry> => List.concat(acc, entries))
+}
+
+pub fn collectAllTags(sections: List<String>, contentDir: String): List<TagEntry> with {File} =
+    match List.head(sections) {
+    None => [],
+    Some(section) => {
+    let posts = readSection(contentDir, section)
+    let tags = collectTags(section, posts)
+    match List.tail(sections) {
+    Some(rest) => List.concat(tags, collectAllTags(rest, contentDir)),
+    None => tags,
+}
+},
+}
+
+fn addIfUnique(acc: List<String>, e: TagEntry): List<String> =
+    if List.any(acc, fn(t: String): Bool => t == tagName(e)) then acc else List.concat(acc, [tagName(e)])
+
+pub fn uniqueTags(entries: List<TagEntry>): List<String> = List.fold(entries, [], addIfUnique)
+
+pub fn entriesForTag(entries: List<TagEntry>, tag: String): List<TagEntry> =
+    List.filter(entries, fn(e: TagEntry): Bool => tagName(e) == tag)
+
+// --- File I/O ---
+
+pub fn ensureDir(dirPath: String): Unit with {File} = {
+    if File.exists(dirPath) then () else {
+    let parent = path.dirname(dirPath)
+    if parent != "." then if parent != dirPath then ensureDir(parent) else () else ()
+    File.mkdir(dirPath)
+}
+}
+
+pub fn writePage(outputPath: String, content: String): Unit with {File} = {
+    let dir = path.dirname(outputPath)
+    if dir != "." then ensureDir(dir) else ()
+    File.write(outputPath, content)
+}