Split out four new crates (#5302)

1 files changed, 59 insertions, 0 deletions

diff --git a/crates/typst-library/src/loading/read.rs b/crates/typst-library/src/loading/read.rs
new file mode 100644
index 00000000..23e6e27e
--- /dev/null
+++ b/crates/typst-library/src/loading/read.rs
@@ -0,0 +1,59 @@
+use ecow::EcoString;
+use typst_syntax::Spanned;
+
+use crate::diag::{At, SourceResult};
+use crate::engine::Engine;
+use crate::foundations::{func, Cast};
+use crate::loading::Readable;
+use crate::World;
+
+/// Reads plain text or data from a file.
+///
+/// By default, the file will be read as UTF-8 and returned as a [string]($str).
+///
+/// If you specify `{encoding: none}`, this returns raw [bytes] instead.
+///
+/// # Example
+/// ```example
+/// An example for a HTML file: \
+/// #let text = read("example.html")
+/// #raw(text, lang: "html")
+///
+/// Raw bytes:
+/// #read("tiger.jpg", encoding: none)
+/// ```
+#[func]
+pub fn read(
+    /// The engine.
+    engine: &mut Engine,
+    /// Path to a file.
+    ///
+    /// For more details, see the [Paths section]($syntax/#paths).
+    path: Spanned<EcoString>,
+    /// The encoding to read the file with.
+    ///
+    /// If set to `{none}`, this function returns raw bytes.
+    #[named]
+    #[default(Some(Encoding::Utf8))]
+    encoding: Option<Encoding>,
+) -> SourceResult<Readable> {
+    let Spanned { v: path, span } = path;
+    let id = span.resolve_path(&path).at(span)?;
+    let data = engine.world.file(id).at(span)?;
+    Ok(match encoding {
+        None => Readable::Bytes(data),
+        Some(Encoding::Utf8) => Readable::Str(
+            std::str::from_utf8(&data)
+                .map_err(|_| "file is not valid utf-8")
+                .at(span)?
+                .into(),
+        ),
+    })
+}
+
+/// An encoding of a file.
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Cast)]
+pub enum Encoding {
+    /// The Unicode UTF-8 encoding.
+    Utf8,
+}