microengine: compound operators

6 files changed, 71 insertions, 18 deletions

diff --git a/uscript/parser.c b/uscript/parser.c
index 5740474..f2c601a 100644
--- a/uscript/parser.c
+++ b/uscript/parser.c
@@ -399,6 +399,18 @@ void parse_arr(struct parser *p)
 }
 
 static
+void parser_add_var_access(struct parser *p, u8 acc, int var)
+{
+        parser_add_byte(p, acc);
+        if (acc == BC_SET_GLOBAL || acc == BC_GET_GLOBAL) {
+                parser_add_byte(p, (var >> 8) & 0xFF);
+                parser_add_byte(p, var & 0xFF);
+        } else {
+                parser_add_byte(p, (u8)var);
+        }
+}
+
+static
 void parse_ident(struct parser *p)
 {
         struct token ident = p->prev;
@@ -423,19 +435,31 @@ void parse_ident(struct parser *p)
                 return;
         }
 
+#define compound_op(op) \
+        do { \
+                parser_add_var_access(p, getter, var); \
+                expr(p); \
+                parser_add_byte(p, op); \
+                parser_add_var_access(p, setter, var); \
+        } while (false)
+
         if (p->can_assign && consume(p, '=')) {
                 expr(p);
-                parser_add_byte(p, setter);
+                parser_add_var_access(p, setter, var);
+        } else if (p->can_assign && consume(p, TOKEN_PLUS_EQL)) {
+                compound_op(BC_ADD);
+        } else if (p->can_assign && consume(p, TOKEN_MINUS_EQL)) {
+                compound_op(BC_SUB);
+        } else if (p->can_assign && consume(p, TOKEN_MULT_EQL)) {
+                compound_op(BC_MULT);
+        } else if (p->can_assign && consume(p, TOKEN_DIV_EQL)) {
+                compound_op(BC_DIV);
+        } else if (p->can_assign && consume(p, TOKEN_MOD_EQL)) {
+                compound_op(BC_MOD);
         } else {
-                parser_add_byte(p, getter);
-        }
-
-        if (setter == BC_SET_GLOBAL) {
-                parser_add_byte(p, (var >> 8) & 0xFF);
-                parser_add_byte(p, var & 0xFF);
-        } else {
-                parser_add_byte(p, (u8)var);
+                parser_add_var_access(p, getter, var);
         }
+#undef compound_op
 }
 
 static
@@ -503,15 +527,36 @@ void parse_call(struct parser *p)
 static
 void parse_index(struct parser *p)
 {
+        bool can_assign = p->can_assign;
+
         expr(p);
         expect(p, ']', "expected ']'");
 
-        if (consume(p, '=')) {
+#define compound_op(op) \
+        do { \
+                parser_add_byte(p, BC_PUSH_INDEX); \
+                expr(p); \
+                parser_add_byte(p, op); \
+                parser_add_byte(p, BC_SET_INDEX); \
+        } while (false)
+
+        if (can_assign && consume(p, '=')) {
                 expr(p);
                 parser_add_byte(p, BC_SET_INDEX);
+        } else if (can_assign && consume(p, TOKEN_PLUS_EQL)) {
+                compound_op(BC_ADD);
+        } else if (can_assign && consume(p, TOKEN_MINUS_EQL)) {
+                compound_op(BC_SUB);
+        } else if (can_assign && consume(p, TOKEN_MULT_EQL)) {
+                compound_op(BC_MULT);
+        } else if (can_assign && consume(p, TOKEN_DIV_EQL)) {
+                compound_op(BC_DIV);
+        } else if (can_assign && consume(p, TOKEN_MOD_EQL)) {
+                compound_op(BC_MOD);
         } else {
                 parser_add_byte(p, BC_GET_INDEX);
         }
+#undef compound_op
 }
 
 static
diff --git a/uscript/us_debug.c b/uscript/us_debug.c
index 18be587..8898211 100644
--- a/uscript/us_debug.c
+++ b/uscript/us_debug.c
@@ -80,6 +80,7 @@ int print_instruction(struct us_proto *proto, int idx)
         case BC_FALSE:
         case BC_TRUE:
         case BC_ZILCH:
+        case BC_PUSH_INDEX:
         case BC_GET_INDEX:
         case BC_SET_INDEX:
         case BC_POP:
diff --git a/uscript/uscript.c b/uscript/uscript.c
index 0e6fc4b..d82ce35 100644
--- a/uscript/uscript.c
+++ b/uscript/uscript.c
@@ -12,7 +12,7 @@ void core_print(int argc)
 {
         (void)argc;
 
-        char *str = val_to_str(vm_peek(), NULL);
+        char *str = val_to_str(vm_peek(0), NULL);
         olog(str);
         mem_free(str);
 
@@ -23,7 +23,7 @@ void core_len(int argc)
 {
         (void)argc;
 
-        struct us_val val = vm_peek();
+        struct us_val val = vm_peek(0);
         switch (val.type) {
         case VAL_ARR:
                 vm_push(create_num(da_len(get_arr(val)->e)));
@@ -43,6 +43,7 @@ void core_range_next(int argc)
         struct us_cfunc *cfunc = get_cfunc(vm_get(-1));
         double min = get_num(cfunc_get_upval(cfunc, 0));
         double max = get_num(cfunc_get_upval(cfunc, 1));
+        double inc = get_num(cfunc_get_upval(cfunc, 2));
 
         if (min == max) {
                 vm_push(create_zilch());
@@ -51,7 +52,6 @@ void core_range_next(int argc)
 
         vm_push(create_num(min));
 
-        int inc = max > min ? 1 : -1;
         cfunc_set_upval(cfunc, 0, create_num(min + inc));
 }
 
diff --git a/uscript/vm.c b/uscript/vm.c
index 4064e12..9fbd8c0 100644
--- a/uscript/vm.c
+++ b/uscript/vm.c
@@ -245,20 +245,26 @@ void us_exec(struct us_func *func)
                         vm_push(vm.cf->stackbot[read_byte()]);
                         break;
                 case BC_SET_LOCAL:
-                        vm.cf->stackbot[read_byte()] = vm_peek();
+                        vm.cf->stackbot[read_byte()] = vm_peek(0);
                         break;
                 case BC_GET_GLOBAL:
                         vm_push(get_global(read_short()));
                         break;
                 case BC_SET_GLOBAL:
-                        set_global(read_short(), vm_peek());
+                        set_global(read_short(), vm_peek(0));
                         break;
                 case BC_GET_UPVAL:
                         vm_push(*func->upvals[read_byte()]->loc);
                         break;
                 case BC_SET_UPVAL:
-                        *func->upvals[read_byte()]->loc = vm_peek();
+                        *func->upvals[read_byte()]->loc = vm_peek(0);
                         break;
+                case BC_PUSH_INDEX: {
+                        struct us_val idx_val = vm_peek(0);
+                        struct us_val idxee_val = vm_peek(1);
+                        index_val(idx_val, idxee_val);
+                        break;
+                }
                 case BC_GET_INDEX: {
                         struct us_val idx_val = vm_pop();
                         struct us_val idxee_val = vm_pop();
@@ -403,7 +409,7 @@ void us_exec(struct us_func *func)
                 }
                 case BC_FALSEY_JMP: {
                         u16 jmp = read_short();
-                        if (as_bool(vm_peek()))
+                        if (as_bool(vm_peek(0)))
                                 break;
                         i += jmp;
                         break;
diff --git a/uscript/vm.h b/uscript/vm.h
index 9ab1407..a20aa61 100644
--- a/uscript/vm.h
+++ b/uscript/vm.h
@@ -8,7 +8,7 @@
 #define STACK_SIZE (MAX_CALL_FRAMES * 256)
 
 #define vm_pop()   (*(--vm.stacktop))
-#define vm_peek()  (vm.stacktop[-1])
+#define vm_peek(i)  (vm.stacktop[-1 - i])
 #define vm_push(v) (*vm.stacktop++ = (v))
 
 #define vm_get(i)  (vm.cf->stackbot[i])
diff --git a/uscript/xbytecode.h b/uscript/xbytecode.h
index 34f7f43..1a7f359 100644
--- a/uscript/xbytecode.h
+++ b/uscript/xbytecode.h
@@ -11,6 +11,7 @@ BC(GET_GLOBAL)
 BC(SET_GLOBAL)
 BC(GET_UPVAL)
 BC(SET_UPVAL)
+BC(PUSH_INDEX)
 BC(GET_INDEX)
 BC(SET_INDEX)
 BC(POP)