mst: process file

src/main.rs

@@ -1,3 +1,42 @@
-fn main() {
-    println!("Hello, world!");
+extern crate mustache;
+
+use mustache::MapBuilder;
+use std::env;
+use std::error::Error;
+use std::io;
+
+fn pairs<I>(data: I) -> impl Iterator<Item = (I::Item, I::Item)>
+where
+    I: Iterator + Clone,
+{
+    let left = data.clone().step_by(2);
+    let right = data.skip(1).step_by(2);
+    left.zip(right)
+}
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let args: Vec<_> = env::args().skip(1).collect(); // args without binary name
+    let source_path = args
+        .first()
+        .ok_or("first argument needs to be a file path")?;
+    let template = mustache::compile_path(source_path)?;
+
+    let data = {
+        let mut data = MapBuilder::new();
+        for (k, v) in pairs(args.iter().skip(1)) {
+            data = data.insert_str(k, v);
+        }
+
+        data = data.insert_str("MST_SOURCE", source_path);
+
+        // TODO: include (flag)
+        // TODO: cmd (flag)
+        // TODO: maybe_env
+        // TODO: env
+
+        data.build()
+    };
+
+    template.render_data(&mut io::stdout(), &data)?;
+    Ok(())
 }