Move docs generation code (#3519)

1 files changed, 108 insertions, 0 deletions

diff --git a/docs/src/link.rs b/docs/src/link.rs
new file mode 100644
index 00000000..f4d803c3
--- /dev/null
+++ b/docs/src/link.rs
@@ -0,0 +1,108 @@
+use typst::diag::{bail, StrResult};
+use typst::foundations::Func;
+
+use crate::{get_module, GROUPS, LIBRARY};
+
+/// Resolve an intra-doc link.
+pub fn resolve(link: &str, base: &str) -> StrResult<String> {
+    if link.starts_with('#') || link.starts_with("http") {
+        return Ok(link.to_string());
+    }
+
+    let (head, tail) = split_link(link)?;
+    let mut route = match resolve_known(head, base) {
+        Some(route) => route,
+        None => resolve_definition(head, base)?,
+    };
+
+    if !tail.is_empty() {
+        route.push('/');
+        route.push_str(tail);
+    }
+
+    if !route.contains('#') && !route.ends_with('/') {
+        route.push('/');
+    }
+
+    Ok(route)
+}
+
+/// Split a link at the first slash.
+fn split_link(link: &str) -> StrResult<(&str, &str)> {
+    let first = link.split('/').next().unwrap_or(link);
+    let rest = link[first.len()..].trim_start_matches('/');
+    Ok((first, rest))
+}
+
+/// Resolve a `$` link head to a known destination.
+fn resolve_known(head: &str, base: &str) -> Option<String> {
+    Some(match head {
+        "$tutorial" => format!("{base}tutorial"),
+        "$reference" => format!("{base}reference"),
+        "$category" => format!("{base}reference"),
+        "$syntax" => format!("{base}reference/syntax"),
+        "$styling" => format!("{base}reference/styling"),
+        "$scripting" => format!("{base}reference/scripting"),
+        "$context" => format!("{base}reference/context"),
+        "$guides" => format!("{base}guides"),
+        "$packages" => format!("{base}packages"),
+        "$changelog" => format!("{base}changelog"),
+        "$community" => format!("{base}community"),
+        _ => return None,
+    })
+}
+
+/// Resolve a `$` link to a global definition.
+fn resolve_definition(head: &str, base: &str) -> StrResult<String> {
+    let mut parts = head.trim_start_matches('$').split('.').peekable();
+    let mut focus = &LIBRARY.global;
+    let mut category = None;
+
+    while let Some(name) = parts.peek() {
+        if category.is_none() {
+            category = focus.scope().get_category(name);
+        }
+        let Ok(module) = get_module(focus, name) else { break };
+        focus = module;
+        parts.next();
+    }
+
+    let Some(category) = category else { bail!("{head} has no category") };
+
+    let name = parts.next().ok_or("link is missing first part")?;
+    let value = focus.field(name)?;
+
+    // Handle grouped functions.
+    if let Some(group) = GROUPS.iter().find(|group| {
+        group.category == category.name() && group.filter.iter().any(|func| func == name)
+    }) {
+        let mut route = format!(
+            "{}reference/{}/{}/#functions-{}",
+            base, group.category, group.name, name
+        );
+        if let Some(param) = parts.next() {
+            route.push('-');
+            route.push_str(param);
+        }
+        return Ok(route);
+    }
+
+    let mut route = format!("{}reference/{}/{name}/", base, category.name());
+    if let Some(next) = parts.next() {
+        if value.field(next).is_ok() {
+            route.push_str("#definitions-");
+            route.push_str(next);
+        } else if value
+            .clone()
+            .cast::<Func>()
+            .map_or(false, |func| func.param(next).is_some())
+        {
+            route.push_str("#parameters-");
+            route.push_str(next);
+        } else {
+            bail!("field {next} not found");
+        }
+    }
+
+    Ok(route)
+}