some stuff

src/parser.ts

@@ -0,0 +1,45 @@
+import { FunctionDef, Item } from "./ast";
+import { CompilerError, todo } from "./error";
+import { Token } from "./lexer";
+
+export function parse(t: Token[]): Item[] {
+    const items: Item[] = [];
+
+    while (t.length > 0) {
+        let item;
+        [t, item] = parseItem(t);
+        items.push(item);
+    }
+
+    return items;
+}
+
+function parseItem(t: Token[]): [Token[], Item] {
+    let next;
+    [t, next] = nextT(t);
+    if (next.kind === "kw_function") {
+
+        const def: FunctionDef = {
+            name: "",
+            args: [],
+            body: todo("todo", next.span)
+        }
+
+        return [t, {kind: "function", node: def, span: next.span}]
+    } else {
+        unexpectedToken(next);
+    }
+}
+
+function nextT(t: Token[]): [Token[], Token] {
+    const next = t[0];
+    if (!next) {
+        throw new CompilerError("unexpected end of file", {start: Number.MAX_SAFE_INTEGER, end: Number.MAX_SAFE_INTEGER})
+    }
+    const rest = t.slice(1);
+    return [rest, next];
+}
+
+function unexpectedToken(token: Token): never {
+    throw new CompilerError("unexpected token", token.span);
+}