implement switch statement

1 files changed, 45 insertions, 0 deletions

diff --git a/test/bf.c b/test/bf.c
new file mode 100644
index 0000000..2ebdbb8
--- /dev/null
+++ b/test/bf.c
@@ -0,0 +1,45 @@
+unsigned char M[1<<15];
+
+void bf(const char *p)
+{
+   extern int putchar(int);
+   extern int getchar(void);
+   static unsigned char *const Mend = M + sizeof M;
+   int b;
+   unsigned char *m = M;
+
+   while (*p) {
+      switch (*p) {
+      case '+': ++*m; break;
+      case '-': --*m; break;
+      case '<': if (m == M) m = Mend; else --m; break;
+      case '>': if (m == Mend) m = M; else ++m; break;
+      case '.': putchar(*m); break;
+      case ',': *m = getchar(); break;
+      case '[':
+         if (*m) break;
+         b = 0;
+         do switch (*p++) {
+         case '[': ++b; break;
+         case ']': --b; break;
+         case 0: return;
+         } while (b != 0);
+         continue;
+      case ']':
+         if (!*m) break;
+         b = 0;
+         do switch (*p--) {
+         case '[': ++b; break;
+         case ']': --b; break;
+         case 0: return;
+         } while (b != 0);
+         break;
+      }
+      ++p;
+   }
+}
+
+int main(int argc, char **argv) {
+   const char *p = "++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++.";
+   bf(argc < 2 ? p : argv[1]);
+}