feat(tazjin/rlox): Wire up parser to the REPL

Change-Id: I940448c63ce105d53a0f281b6320ffb01378f207
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2235
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI

users/tazjin/rlox/src/parser.rs

@@ -11,17 +11,17 @@ use crate::scanner::{Token, TokenKind};
 // AST
 
 #[derive(Debug)]
-struct Binary<'a> {
+pub struct Binary<'a> {
     left: Box<Expr<'a>>,
     operator: Token<'a>,
     right: Box<Expr<'a>>,
 }
 
 #[derive(Debug)]
-struct Grouping<'a>(Box<Expr<'a>>);
+pub struct Grouping<'a>(Box<Expr<'a>>);
 
 #[derive(Debug)]
-enum Literal {
+pub enum Literal {
     Boolean(bool),
     Number(f64),
     String(String),
@@ -29,13 +29,13 @@ enum Literal {
 }
 
 #[derive(Debug)]
-struct Unary<'a> {
+pub struct Unary<'a> {
     operator: Token<'a>,
     right: Box<Expr<'a>>,
 }
 
 #[derive(Debug)]
-enum Expr<'a> {
+pub enum Expr<'a> {
     Binary(Binary<'a>),
     Grouping(Grouping<'a>),
     Literal(Literal),
@@ -200,3 +200,9 @@ impl<'a> Parser<'a> {
         return Ok(expr);
     }
 }
+
+pub fn parse<'a>(tokens: Vec<Token<'a>>) -> ExprResult<'a> {
+    let mut parser = Parser { tokens, current: 0 };
+
+    parser.expression()
+}