1 files changed, 104 insertions, 0 deletions
diff --git a/l/bf.lang b/l/bf.lang
new file mode 100644
index 0000000..0ce6389
--- /dev/null
+++ b/l/bf.lang
@@ -0,0 +1,104 @@
+type byte := char;
+
+func putstr(char[] str) {
+	int i := 0;
+	while (str[i] != '\0') {
+		putc(str[i]);
+		i = i + 1;
+	}
+}
+
+func int[] makejumpmap(char[] src, int srclen) {
+	int[] jm := new int[srclen];
+	int[] stack := new int[srclen];
+	int stkp := 0;
+	int i := 0;
+	while (i < srclen) {
+		// putint(i); putc(' '); putint(stkp); putc(' '); putc(src[i]); putc('\n');
+		if (src[i] == '[') {
+			stack[stkp] = i;
+			stkp = stkp + 1;
+		}
+		if (src[i] == ']') {
+			stkp = stkp - 1;
+			int j := stack[stkp];
+			jm[i] = j;
+			jm[j] = i;
+		}
+		i = i + 1;
+	}
+	if (stkp != 0) {
+		putstr("Unmatched opening brackets in BF source\n");
+		exit(1);
+	}
+	/*i = 0;
+	while (i < srclen) {
+		putint(jm[i]);
+		putc(' ');
+		i = i + 1;
+	}
+	putc('\n');*/
+	return jm;
+}
+
+func interpret(char[] src, int srclen) {
+	int[] jm := makejumpmap(src, srclen);
+	byte[] mem := new char[4088];
+	int ip := 0;
+	int memp := 0;
+	while (src[ip] != '\0') {
+		// putint(ip); putc('\n');
+		char c := src[ip];
+		if (c == '+') {mem[memp] = mem[memp] + byte(1);}
+		if (c == '-') {mem[memp] = mem[memp] - byte(1);}
+		if (c == '>') {memp = memp + 1;}
+		if (c == '<') {memp = memp - 1;}
+		if (c == '.') {putc(mem[memp]);}
+		if (c == ',') {mem[memp] = byte(getc());}
+		if (c == '[') {
+			if (mem[memp] == '\0') {
+				ip = jm[ip];
+			}
+		}
+		if (c == ']') {
+			if (mem[memp] != '\0') {
+				ip = jm[ip];
+			}
+		}
+		ip = ip + 1;
+	}
+
+	// debugger;
+
+	putc('\n');
+	memp = 0;
+	while (memp < 10) {
+		putint(int(mem[memp]) & 0xff); putc(' ');
+		memp = memp + 1;
+	}
+	putc('\n');
+}
+
+func int main() {
+	int bufsize := 12280;
+	char[] source := new char[12280];
+
+	int sourcelen := 0;
+	while (1) {
+		int c := getc();
+		// putc(char(c));
+		if (c < 0) {
+			break;
+		} else {
+			source[sourcelen] = char(c);
+			sourcelen = sourcelen + 1;
+			if (sourcelen >= bufsize - 1) {
+				break;
+			}
+		}
+	}
+	source[sourcelen] = '\0';
+
+	interpret(source, sourcelen);
+	return 0;
+}