Initial stdlib

src/engine/mod.rs

@@ -1,3 +1,4 @@
 pub mod runtime;
 mod test;
-mod http;
+mod http;
+mod stdlib;

src/engine/runtime.rs

@@ -17,7 +17,7 @@ use crate::{
 use super::{http::{
     parse_request_tcp, serialize_response,
     Responses::{self, ok_html},
-};
+}, stdlib};
 
 /// A runtime error.
 pub struct WXRuntimeError {
@@ -165,6 +165,8 @@ impl WXRTHandlerCall {
     /// Execute the handler in the given context and return the result.
     fn execute(&self, ctx: &WXRTContext, info: &WXRuntimeInfo) -> Result<WXRTValue, WXRuntimeError> {
         let args = self.args.iter().map(|arg| eval_literal(arg, &ctx)).collect::<Result<Vec<_>, _>>()?;
+        // Try to call a native handler.
+        if let Some(native_res) = stdlib::try_call(&self.name, args, info) { return native_res; }
         // TODO: Add support for custom user-defined handlers
         Err(WXRuntimeError {
             code: 500,

src/engine/stdlib.rs

@@ -0,0 +1,43 @@
+use crate::reporting::error::ERROR_HANDLER_CALL;
+
+use super::runtime::{WXRTValue, WXRuntimeError, WXRuntimeInfo};
+
+/// Serve static content from the filesystem.
+/// 
+/// # Arguments
+/// - `path`: The path to the file to serve relative to the project root.
+fn webx_static(relative_path: &WXRTValue, info: &WXRuntimeInfo) -> Result<WXRTValue, WXRuntimeError> {
+    // Read the file from the filesystem.
+    if let WXRTValue::String(path) = relative_path {
+        let file = std::fs::read(info.project_root.join(path));
+        if let Ok(file) = file {
+            return Ok(WXRTValue::String(String::from_utf8(file).unwrap()));
+        } else {
+            return Err(WXRuntimeError {
+                message: format!("static: failed to read file '{}'", path),
+                code: ERROR_HANDLER_CALL
+            });
+        }
+    }
+    Err(WXRuntimeError {
+        message: format!("static: failed to read file '{}'", relative_path.to_js()),
+        code: ERROR_HANDLER_CALL
+    })
+}
+
+pub fn try_call(name: &str, args: Vec<WXRTValue>, info: &WXRuntimeInfo) -> Option<Result<WXRTValue, WXRuntimeError>> {
+    let assert_args = |n: usize| {
+        if args.len() != n {
+            return Some(Err::<WXRTValue, WXRuntimeError>(WXRuntimeError {
+                message: format!("{}: expected {} arguments, got {}", name, n, args.len()),
+                code: ERROR_HANDLER_CALL
+            }));
+        }
+        None
+    };
+
+    match name {
+        "static" => Some(match assert_args(1) { Some(err) => err, None => webx_static(&args[0], info) }),
+        _ => None
+    }
+}