From 27bc69806a6bb0f96cce0ab91ef9192f52936cf7 Mon Sep 17 00:00:00 2001
From: Joscha <joscha@plugh.de>
Date: Fri, 18 Nov 2022 14:12:10 +0100
Subject: [PATCH] Parse variable expressions

---
 src/parser.rs | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/parser.rs b/src/parser.rs
index 3fd16f6..cfcded6 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -194,13 +194,29 @@ fn table_constr(
         })
 }
 
+fn expr_var(
+    expr: impl Parser<char, Expr, Error = Error> + Clone,
+) -> impl Parser<char, Expr, Error = Error> {
+    just("[")
+        .ignore_then(space())
+        .then(expr)
+        .then(space())
+        .then_ignore(just("]"))
+        .map_with_span(|((s0, index), s1), span| Expr::Var {
+            s0,
+            index: Box::new(index),
+            s1,
+            span,
+        })
+}
+
 fn expr(
     expr: impl Parser<char, Expr, Error = Error> + Clone,
 ) -> impl Parser<char, Expr, Error = Error> {
     let lit = lit(expr.clone()).map(Expr::Lit);
     let table_constr = table_constr(expr.clone()).map(Expr::TableConstr);
 
-    lit.or(table_constr)
+    lit.or(table_constr).or(expr_var(expr))
 }
 
 pub fn parser() -> impl Parser<char, Expr, Error = Error> {