From 738121c18a43146d4ba6a91c7d878026590222c3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Madeleine=20Sydney=20=C5=9Alaga?= <msyds@deertopia.net>
Date: Tue, 22 Sep 2026 04:03:02 -0600
Subject: [PATCH]

---
 src/r7rs.ebnf | 14 ++++++++++++--
 src/scm.clj   | 11 ++++++++++-
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/src/r7rs.ebnf b/src/r7rs.ebnf
index 79a7c7b..fd47ea7 100644
--- a/src/r7rs.ebnf
+++ b/src/r7rs.ebnf
@@ -5,11 +5,17 @@ boolean = #"#(t(rue)?|f(alse)?)" <intertoken-space>
 semicolon = ';'
 left-paren = '(' <intertoken-space>
 right-paren = ')' <intertoken-space>
+dot = '.' <intertoken-space>
 
 (* datum *)
-<datum> = simple-datum
+<datum> = simple-datum | compound-datum
+<simple-datum> = boolean | symbol | number | string
+<compound-datum> = any-list
 
-<simple-datum> = boolean | symbol | number
+(* list *)
+<any-list> = proper-list | improper-list
+proper-list = <left-paren> datum* <right-paren>
+improper-list = <left-paren> datum+ <dot> datum <right-paren>
 
 (* symbol *)
 symbol = ordinary-symbol <intertoken-space>
@@ -23,6 +29,10 @@ num-10 = sign #"[0-9]+"
 sign = ('+' | '-')?
 exactness = ('#i' | '#e')?
 
+(* string *)
+string = <'"'> string-element* <'"'> <intertoken-space>
+<string-element> = #'[^"\\]' | '\\"' | '\\\\'
+
 (* atmosphere *)
 atmosphere = whitespace | comment | directive
 whitespace = intraline-whitespace | line-ending
diff --git a/src/scm.clj b/src/scm.clj
index 474d8ef..9fad3bd 100644
--- a/src/scm.clj
+++ b/src/scm.clj
@@ -1,7 +1,8 @@
 (ns scm
   (:require [instaparse.core :as insta]
             [clojure.java.io :as io]
-            [clojure.core.match :refer [match]])
+            [clojure.core.match :refer [match]]
+            [clojure.string :as str])
   (:refer-clojure :exclude [read]))
 
 
@@ -60,6 +61,14 @@
                      (match x
                        (:or "#t" "#true") true
                        (:or "#f" "#false") false)])
+         :string (fn [& els]
+                   (apply str
+                          (for [e els]
+                            (match e
+                              "\\\\" "\\"
+                              "\\\"" "\""
+                              "\\n" "\n"
+                              _ e))))
          :sign (fn
                  ([] identity)
                  ([x] (match x "-" - "+" identity)))