add readline support

Makefile

@@ -4,7 +4,7 @@ build:
 	cd src; \
 	yacc -d parse.y; \
 	lex scan.l
-	gcc -Wall -o bin/picrin -I./include src/main.c src/state.c src/gc.c src/pair.c src/port.c src/symbol.c src/value.c src/y.tab.c src/lex.yy.c src/bool.c src/vm.c src/init.c src/number.c
+	gcc -Wall -o bin/picrin -I./include -lreadline src/main.c src/state.c src/gc.c src/pair.c src/port.c src/symbol.c src/value.c src/y.tab.c src/lex.yy.c src/bool.c src/vm.c src/init.c src/number.c
 
 clean:
 	rm -f src/y.tab.c src/y.tab.h src/lex.yy.c

include/picconf.h

@@ -4,6 +4,9 @@
 /* switch normal VM and direct threaded VM */
 #define PIC_DIRECT_THREADED_VM 1
 
+/* enable readline module */
+#define PIC_ENABLE_READLINE 1
+
 /* initial memory size (to be dynamically extended if necessary) */
 #define PIC_ARENA_SIZE 100
 #define PIC_HEAP_SIZE 8192

src/main.c

@@ -2,6 +2,11 @@
 
 #include "picrin.h"
 
+#if PIC_ENABLE_READLINE
+# include <readline/readline.h>
+# include <readline/history.h>
+#endif
+
 void
 test_object_creation(pic_state *pic)
 {
@@ -30,7 +35,7 @@ int
 main()
 {
   pic_state *pic;
-  char line[LINE_MAX_LENGTH], last_char;
+  char line[LINE_MAX_LENGTH], last_char, *read_line;
   int char_index;
   pic_value v;
   struct pic_proc *proc;
@@ -45,6 +50,18 @@ main()
   ai = pic_gc_arena_preserve(pic);
 
   while (1) {
+
+#if PIC_ENABLE_READLINE
+    read_line = readline("> ");
+    if (read_line == NULL) {
+      line[0] = '\0';
+    }
+    else {
+      strncpy(line, read_line, LINE_MAX_LENGTH - 1);
+      add_history(read_line);
+      free(read_line);
+    }
+#else
     printf("> ");
 
     char_index = 0;
@@ -56,6 +73,7 @@ main()
       line[char_index++] = last_char;
     }
     line[char_index] = '\0';
+#endif
 
     /* read */
     v = pic_parse(pic, line);