From b99be4933bcb850cbaf96f89750e925ecf2e8386 Mon Sep 17 00:00:00 2001
From: Felix Perktold <Felix.Perktold@student.uibk.ac.at>
Date: Tue, 23 Dec 2025 13:36:33 +0100
Subject: rename eq? to equal?, fix syntax error on empty newline

---
 Makefile | 2 +-
 lisp.c   | 2 +-
 lisp.h   | 2 +-
 lisp.l   | 5 +++--
 lisp.y   | 9 +++++----
 main.c   | 2 +-
 6 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/Makefile b/Makefile
index d6d3fae..095a7ae 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 LEX     = flex
 YACC    = bison
-CC      = gcc -g -Wall -Werror
+CC      = gcc -g
 CFLAGS  = -DYYDEBUG=1
 LIBS    = -lreadline -lfl -lm
 OBJS	= lisp.o lisp.tab.o lex.yy.o
diff --git a/lisp.c b/lisp.c
index 1695ff7..6b34bab 100644
--- a/lisp.c
+++ b/lisp.c
@@ -356,7 +356,7 @@ int value_eq(value *a, value *b) {
 	return 1;
 }
 
-value *builtin_eq(env *e, value *args) {
+value *builtin_equal(env *e, value *args) {
 	value *v_prev = eval(e, car(args));
 
 	args = cdr(args);
diff --git a/lisp.h b/lisp.h
index 45986a6..a422c9b 100644
--- a/lisp.h
+++ b/lisp.h
@@ -76,7 +76,7 @@ value *builtin_car(env *e, value *args);
 value *builtin_cdr(env *e, value *args);
 value *builtin_reverse(env *e, value *args);
 value *builtin_isnull(env *e, value *args);
-value *builtin_eq(env *e, value *args);
+value *builtin_equal(env *e, value *args);
 value *builtin_add(env *e, value *args);
 value *builtin_sub(env *e, value *args);
 value *builtin_mul(env *e, value *args);
diff --git a/lisp.l b/lisp.l
index fa2203a..cb0453a 100644
--- a/lisp.l
+++ b/lisp.l
@@ -7,8 +7,9 @@ int tcnt = 0;
 %}
 
 %%
-[[:space:]]+    { /* ignore whitespace */ }
-";"[^\n]*       { /* ignore comment */   }
+[[:space:]&&[^\n]]+    { /* ignore whitespace */ }
+";"[^\n]*       { /* ignore comment */ }
+\n              { return NLINE; }
 "("             { return LPAREN; }
 ")"             { return RPAREN; }
 "\."            { return DOT; }
diff --git a/lisp.y b/lisp.y
index 5a39640..086ef93 100644
--- a/lisp.y
+++ b/lisp.y
@@ -8,21 +8,21 @@ int yyerror(const char *s);
 %}
 
 %union {
-        int ival;
         double dval;
         const char *strval;
         value *val;
 }
 %token <dval> NUMBER
 %token <strval> STRING SYMBOL
-%token <ival> LPAREN RPAREN DOT QUOTE
+%token LPAREN RPAREN DOT QUOTE NLINE
 
 %type <val> expr atom list list_items
 
 %start exprs
 
 %%
-exprs: expr
+exprs: /* nothing */
+     | expr
       {
         value *v = eval(global_env, $1);
         printf(";> ");
@@ -38,7 +38,8 @@ exprs: expr
 expr:  atom
      | list
      | LPAREN expr DOT expr RPAREN { $$ = cons($2, $4); }
-     | QUOTE expr { $$ = cons(make_symbol("quote"), cons($2, make_nil())); };
+     | QUOTE expr { $$ = cons(make_symbol("quote"), cons($2, make_nil())); }
+     | NLINE { $$ = make_nil(); };
 
 list: LPAREN list_items RPAREN { $$ = $2; };
 
diff --git a/main.c b/main.c
index 3f851a8..e6f6f97 100644
--- a/main.c
+++ b/main.c
@@ -80,7 +80,7 @@ int main(int argc, char **argv) {
 	env_define(global_env, "cdr", make_builtin(builtin_cdr));
 	env_define(global_env, "reverse", make_builtin(builtin_reverse));
 	env_define(global_env, "null?", make_builtin(builtin_isnull));
-	env_define(global_env, "eq?", make_builtin(builtin_eq));
+	env_define(global_env, "equal?", make_builtin(builtin_equal));
 	env_define(global_env, "+", make_builtin(builtin_add));
 	env_define(global_env, "-", make_builtin(builtin_sub));
 	env_define(global_env, "*", make_builtin(builtin_mul));
-- 
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