7 files changed, 109 insertions, 14 deletions

diff --git a/dis.c b/dis.c
new file mode 100644
index 0000000..09e7571
--- /dev/null
+++ b/dis.c
@@ -0,0 +1,36 @@
+#include "dis.h"
+
+#include <stdio.h>
+#include <stdint.h>
+
+
+
+void disasm_chunk(Chunk *ch) {
+	for (size_t ip = 0; ip < ch->blen; ) {
+		uint8_t instr = ch->b[ip];
+		printf("%04zd\t",ip);
+		ip ++;
+#define SIMPLE_INSTR(opcode, str) \
+	case opcode: puts(str); break;
+		switch (instr) {
+		SIMPLE_INSTR(OP_RET, "ret")
+		case OP_LOADK:;
+			uint8_t ix = ch->b[ip++];
+			printf("loadk #%d\t; ",ix);
+			Val k = ch->c[ix];
+			printf("%-4s : ",valty_str(k.ty));
+			println_val(k);
+			break;
+		SIMPLE_INSTR(OP_PRINT, "print")
+		SIMPLE_INSTR(OP_ADD, "add")
+		SIMPLE_INSTR(OP_SUB, "sub")
+		SIMPLE_INSTR(OP_MUL, "mul")
+		SIMPLE_INSTR(OP_DIV, "div")
+		}
+	}
+#undef SIMPLE_INSTR
+}
+
+
+
+
diff --git a/dis.h b/dis.h
new file mode 100644
index 0000000..47aff62
--- /dev/null
+++ b/dis.h
@@ -0,0 +1,8 @@
+#ifndef _dis_h
+#define _dis_h
+
+#include "vm.h"
+
+void disasm_chunk(Chunk *ch);
+
+#endif
diff --git a/val.c b/val.c
index 4456148..9e832a6 100644
--- a/val.c
+++ b/val.c
@@ -4,13 +4,28 @@
 void print_val(Val v) {
 	switch (v.ty) {
 	case TY_NIL:
-		printf("nil\n");
+		printf("nil");
 		break;
 	case TY_NUM:
-		printf("%f\n",AS_NUM(v));
+		printf("%f",AS_NUM(v));
 		break;
 	case TY_BOOL:
-		printf("%s\n",AS_BOOL(v) ? "true" : "false");
+		printf("%s",AS_BOOL(v) ? "true" : "false");
 		break;
 	}
 }
+
+void println_val(Val v) {
+	print_val(v);
+	putchar('\n');
+}
+
+static const char *ty_names[] = {
+	"nil",
+	"num",
+	"bool",
+};
+
+const char *valty_str(ValTy ty) {
+	return ty_names[ty];
+}
diff --git a/val.h b/val.h
index 1f2bd8d..bf58c06 100644
--- a/val.h
+++ b/val.h
@@ -30,6 +30,8 @@ struct _obj {
 };
 
 void print_val(Val v);
+void println_val(Val v);
+const char *valty_str(ValTy ty);
 
 
 #define IS_NUM(x) (x.ty == TY_NUM)
diff --git a/vm b/vm
deleted file mode 100755
index 9ecf078..0000000
--- a/vm
+++ /dev/null
diff --git a/vm.c b/vm.c
index 00692b0..72f69fa 100644
--- a/vm.c
+++ b/vm.c
@@ -6,6 +6,7 @@
 
 #include "val.h"
 #include "vm.h"
+#include "dis.h"
 
 void *M(void *p, size_t sz) {
 	if (sz == 0) {
@@ -61,22 +62,26 @@ Vm vm_new(Chunk *ch) {
 
 static void runvm() {
 	Chunk ch = chunk_new();
+
 	chunk_wbc(&ch, OP_LOADK);
-	chunk_wbc(&ch, 1);
-	chunk_wbc(&ch, OP_PRINT);
-	chunk_wbc(&ch, OP_LOADK);
-	chunk_wbc(&ch, 2);
+	chunk_wbc(&ch, chunk_wconst(&ch, VAL_NUM(10.0)));
 	chunk_wbc(&ch, OP_LOADK);
-	chunk_wbc(&ch, 0);
+	chunk_wbc(&ch, chunk_wconst(&ch, VAL_NUM(3.0)));
+	chunk_wbc(&ch, OP_DIV);
+	chunk_wbc(&ch, OP_PRINT);
+
 	chunk_wbc(&ch, OP_RET);
 
-	chunk_wconst(&ch, VAL_BOOL(false));
-	chunk_wconst(&ch, VAL_NIL);
-	chunk_wconst(&ch, VAL_NUM(420.69));
+
+	disasm_chunk(&ch);
 
 	Vm vm = vm_new(&ch);
 #define RBYTE() (vm.ch->b[vm.ip++])
 
+#define PUSH(v) vm.stack[vm.sp++] = v;
+#define POP()   (vm.stack[--vm.sp])
+
+	puts("---");
 	while (1) {
 		uint8_t instr = RBYTE();
 		switch (instr) {
@@ -84,14 +89,38 @@ static void runvm() {
 			printf("done!\n");
 			goto done;
 			break;
-		case OP_LOADK:
+		case OP_LOADK:;
 			uint8_t cix = RBYTE();
 			Val v = vm.ch->c[cix];
-			print_val(v);
+			PUSH(v);
+			// printf("   (pushing ");
+			// print_val(v);
+			// printf(")\n");
 			break;
 		case OP_PRINT:
-			printf("print\n");
+			println_val(POP());
+			break;
+
+#define ARITH_OP(opcode, OP) \
+		case opcode: { \
+			Val b = POP(); \
+			Val a = POP(); \
+			if (!IS_NUM(a) || !IS_NUM(b)) { \
+				printf("can't do arithmetic on %s and %s\n", \
+					valty_str(a.ty), valty_str(b.ty)); \
+				goto done; \
+			} \
+			PUSH(VAL_NUM(AS_NUM(a) OP AS_NUM(b))); \
+			} \
 			break;
+
+			ARITH_OP(OP_ADD, +)
+			ARITH_OP(OP_SUB, -)
+			ARITH_OP(OP_MUL, *)
+			ARITH_OP(OP_DIV, /)
+#undef ARITH_OP
+
+
 		}
 	}
 	done:;
diff --git a/vm.h b/vm.h
index 7f76e05..cfa3f6d 100644
--- a/vm.h
+++ b/vm.h
@@ -36,6 +36,11 @@ typedef enum {
 	OP_RET,
 	OP_LOADK,
 	OP_PRINT,
+
+	OP_ADD,
+	OP_SUB,
+	OP_MUL,
+	OP_DIV,
 } Op;