Implemented functions and aliases

src/builtin/alias.rs

@@ -0,0 +1,19 @@
+use crate::prelude::*;
+
+pub fn alias(node: Node, shenv: &mut ShEnv) -> ShResult<()> {
+	let rule = node.into_rule();
+	if let NdRule::Command { argv, redirs: _ } = rule {
+		let argv = argv.drop_first();
+		let mut argv_iter = argv.into_iter();
+		while let Some(arg) = argv_iter.next() {
+			let arg_raw = arg.to_string();
+			if let Some((alias,body)) = arg_raw.split_once('=') {
+				let clean_body = trim_quotes(&body);
+				shenv.logic_mut().set_alias(alias, &clean_body);
+			} else {
+				return Err(ShErr::full(ShErrKind::SyntaxErr, "Expected an assignment in alias args", arg.span().clone()))
+			}
+		}
+	} else { unreachable!() }
+	Ok(())
+}