feat(typst): cross link support (#41)

* feat: cross link support

* dev: encode label into url safe string

* docs: use cross links

contrib/typst/book/lib.typ

@@ -71,6 +71,68 @@
     )) <typst-book-build-meta>
 ]
 
+#let link2page = state("typst-book-link2page", (:))
+
+#let encode-url-component(s) = {
+  let prev = false
+  for (idx, c) in s.codepoints().enumerate() {
+    if c.starts-with(regex("[a-zA-Z]")) {
+      if prev {
+        prev = false
+        "-"
+      }
+      c
+    } else {
+      prev = true
+      if idx != 0 {
+        "-"
+      }
+      str(c.to-unicode())
+    }
+  }
+}
+
+#let cross-link-path-label(path) = {
+  assert(path.starts-with("/"), message: "absolute positioning required")
+  encode-url-component(path)
+}
+
+/// Cross link support
+#let cross-link(path, reference: none, content) = {
+  let path-lbl = cross-link-path-label(path)
+  if reference != none {
+    assert(type(reference) == label, message: "invalid reference")
+  }
+
+  assert(content != none, message: "invalid label content")
+  locate(loc => {
+    let link-result = link2page.final(loc)
+    if path-lbl in link-result {
+      link((page: link-result.at(path-lbl), x: 0pt, y: 0pt), content)
+      return
+    }
+
+    if reference != none {
+      let result = query(reference, loc);
+      // whether it is internal link
+      if result.len() > 0 {
+        link(reference, content)
+        return
+      }
+    }
+    // assert(read(path) != none, message: "no such file")
+
+    link({
+      "cross-link://jump?path-label="
+      path-lbl
+      if reference != none {
+        "&label="
+        encode-url-component(str(reference))
+      }
+    }, content)
+  })
+}
+
 // Collect text content of element recursively into a single string
 // https://discord.com/channels/1054443721975922748/1088371919725793360/1138586827708702810
 #let plain-text(it) = {
@@ -317,6 +379,18 @@
         }
       }
 
+      show : it => {
+        let abs-link = cross-link-path-label("/" + link)
+        locate(loc => {
+          link2page.update(it => {
+            it.insert(abs-link, loc.page())
+            it
+          })
+        })
+
+        it
+      }
+
       visit.at("chapter")(chapter-content)
     }
 

contrib/typst/tidy-book/lib.typ

@@ -0,0 +1 @@
+// https://github.com/Jollywatt/arrow-diagrams

github-pages/docs/book.typ

@@ -51,3 +51,4 @@
 // re-export page template
 #import "/contrib/typst/gh-pages.typ": project
 #let book-page = project
+#let cross-link = cross-link

github-pages/docs/cli/init.typ

@@ -1,10 +1,10 @@
-#import "/github-pages/docs/book.typ": book-page
+#import "/github-pages/docs/book.typ": book-page, cross-link
 
 #show: book-page.with(title: "CLI Init Command")
 
 = The init command
 
-The `init` command will try to initialize your book to build your book successfully by default. It is hence including all of the #link("https://myriad-dreamin.github.io/typst-book/cli/build.html")[options] from `build` command.
+The `init` command will try to initialize your book to build your book successfully by default. It is hence including all of the #cross-link("/cli/build.typ")[options] from `build` command.
 
 For instance, Initialize a book to the directory `my-book`:
 
@@ -29,7 +29,7 @@ typst-book build my-book/ # memoryized dest-dir
 
 == Things to note
 
-The harder way, by creating the book without `init` command, your `book.typ` should at least provides a `book-meta`, as #link("https://myriad-dreamin.github.io/typst-book/guide/get-started.html")[Get Started] shown.
+The harder way, by creating the book without `init` command, your `book.typ` should at least provides a `book-meta`, as #cross-link("/guide/get-started.typ")[Get Started] shown.
 
 ```typ
 #import "@preview/book:0.2.2": *

github-pages/docs/cli/main.typ

@@ -1,22 +1,22 @@
-#import "/github-pages/docs/book.typ": book-page
+#import "/github-pages/docs/book.typ": book-page, cross-link
 
 #show: book-page.with(title: "Command Line Tool")
 
 = Command Line Tool
 
 // todo: cross link
 The `typst-book` command-line tool is used to create and build books.
-After you have #link("https://myriad-dreamin.github.io/typst-book/guide/installation.html")[installed] `typst-book`, you can run the `typst-book help` command in your terminal to view the available commands.
+After you have #cross-link("/guide/installation.typ")[installed] `typst-book`, you can run the `typst-book help` command in your terminal to view the available commands.
 
 This following sections provide in-depth information on the different commands available.
 
 // todo: cross link
-- #link("https://myriad-dreamin.github.io/typst-book/cli/init.html")[`typst-book init <directory>`] — Creates a new book with minimal boilerplate to start with.
-- #link("https://myriad-dreamin.github.io/typst-book/cli/build.html")[`typst-book build`] — Renders the book.
-- #link("https://myriad-dreamin.github.io/typst-book/cli/serve.html")[`typst-book serve`] — Runs a web server to view the book, and rebuilds on changes.
-- #link("https://myriad-dreamin.github.io/typst-book/cli/clean.html")[`typst-book clean`] — Deletes the rendered output.
-- #link("https://myriad-dreamin.github.io/typst-book/cli/completions.html")[`typst-book completions`] — Support for shell auto-completion.
+- #cross-link("/cli/init.typ")[`typst-book init <directory>`] — Creates a new book with minimal boilerplate to start with.
+- #cross-link("/cli/build.typ")[`typst-book build`] — Renders the book.
+- #cross-link("/cli/serve.typ")[`typst-book serve`] — Runs a web server to view the book, and rebuilds on changes.
+- #cross-link("/cli/clean.typ")[`typst-book clean`] — Deletes the rendered output.
+- #cross-link("/cli/completions.typ")[`typst-book completions`] — Support for shell auto-completion.
 
 = Note about the missing `watch` command
 
-We suggest you to use #link("https://github.com/Enter-tainer/typst-preview")[Typst Preview plugin] for preview feature. For more details, please see #link("https://myriad-dreamin.github.io/typst-book/guide/get-started.html")[Get Started] chapter.
+We suggest you to use #link("https://github.com/Enter-tainer/typst-preview")[Typst Preview plugin] for preview feature. For more details, please see #cross-link("/guide/get-started.typ")[Get Started] chapter.

github-pages/docs/cli/serve.typ

@@ -1,4 +1,4 @@
-#import "/github-pages/docs/book.typ": book-page
+#import "/github-pages/docs/book.typ": book-page, cross-link
 
 #show: book-page.with(title: "CLI Serve Command")
 
@@ -30,7 +30,7 @@ typst-book serve path/to/book
 
 == Build options
 
-The `serve` command will build your book once before serving the content. It is hence including all of the #link("https://myriad-dreamin.github.io/typst-book/cli/build.html")[options] from `build` command.
+The `serve` command will build your book once before serving the content. It is hence including all of the #cross-link("/cli/build.typ")[options] from `build` command.
 
 == Server options
 

github-pages/docs/format/book.typ

@@ -1,4 +1,4 @@
-#import "/github-pages/docs/book.typ": book-page
+#import "/github-pages/docs/book.typ": book-page, cross-link
 
 #show: book-page.with(title: "book.typ")
 
@@ -41,7 +41,7 @@ In this example, you specify following fields for the book project:
 - authors #type-hint("array<string>") (optional): Specify the author(s) of the book.
 - summary #type-hint("content") (required): Summarize of the book.
 
-See #link("https://myriad-dreamin.github.io/typst-book/format/book-meta.html")[Book Metadata] for more details.
+See #cross-link("/format/book-meta.typ")[Book Metadata] for more details.
 
 == build-meta
 
@@ -55,4 +55,4 @@ Specify build metadata of the book project. For example:
 
 When you set `build-meta.dest-dir` to `../dist`, `typst-book` will output the generated content to `parent/to/book.typ/../../dist` or `parent/dist`.
 
-See #link("https://myriad-dreamin.github.io/typst-book/format/build-meta.html")[Build Metadata] for more details.
+See #cross-link("/format/build-meta.typ")[Build Metadata] for more details.

github-pages/docs/format/theme.typ

@@ -1,4 +1,4 @@
-#import "/github-pages/docs/book.typ": book-page
+#import "/github-pages/docs/book.typ": book-page, cross-link, cross-link-path-label
 
 #show: book-page.with(title: "Theme")
 
@@ -12,7 +12,9 @@ Currently we have no much design on theme's html part. But you can still configu
 
 == Things to note
 
-Your `book.typ` should at least provides a `book-meta`, as #link("https://myriad-dreamin.github.io/typst-book/guide/get-started.html")[Get Started] shown.
+#let t = cross-link("/guide/get-started.typ")[Get Started]
+
+Your `book.typ` should at least provides a `book-meta`, as #t shown.
 
 ```typ
 #import "@preview/book:0.2.2": *