.

lib/stack.c

@@ -11,6 +11,8 @@ typedef struct {
     size_t    fp_cap;
 } Stack;
 
+static TYC_RESULT stack_push_fp(Stack* s);
+
 static void stack_init(Stack* s)
 {
     s->stack_n = s->fp_n = 0;
@@ -21,15 +23,17 @@ static void stack_init(Stack* s)
 
     assert(s->stack);
     assert(s->fp);
+
+    stack_push_fp(s);
 }
 
-static void stack_destroy(Stack* s)
+static void stack_finalize(Stack* s)
 {
     free(s->stack);
     free(s->fp);
 }
 
-static void stack_push(Stack* s, VALUE v)
+static TYC_RESULT stack_push(Stack* s, VALUE v)
 {
     if (s->stack_n == s->stack_cap) {
         s->stack_cap *= 2;
@@ -39,40 +43,69 @@ static void stack_push(Stack* s, VALUE v)
 
     s->stack[s->stack_n] = v;
     ++s->stack_n;
+    return T_OK;
 }
 
-static VALUE stack_pop(Stack* s)
+static size_t stack_top_fp(Stack* s)
 {
+    return s->fp[s->fp_n - 1];
 }
 
-static VALUE stack_peek(Stack* s)
+static TYC_RESULT stack_peek(Stack* s, VALUE* v_out)
 {
+    if (s->stack_n < stack_top_fp(s))
+        return T_ERR_STACK_UNDERFLOW;
+    *v_out = s->stack[s->stack_n - 1];
+    return T_OK;
 }
 
-static uint32_t stack_len(Stack* s)
+static TYC_RESULT stack_pop(Stack* s, VALUE* v_out)
 {
+    TYC_RESULT err = stack_peek(s, v_out);
+    if (err)
+        return err;
+    --s->stack_n;
+    return T_OK;
+}
+
+static size_t stack_len(Stack* s)
+{
+    return s->stack_n - stack_top_fp(s);
 }
 
 static VALUE stack_get(Stack* s, int32_t key)
 {
+    abort(); // TODO
 }
 
 static void stack_set(Stack* s, int32_t key, VALUE v)
 {
+    abort(); // TODO
 }
 
-static void stack_push_fp(Stack* s)
+static TYC_RESULT stack_push_fp(Stack* s)
 {
+    if (s->fp_n == s->fp_cap) {
+        s->fp_cap *= 2;
+        s->fp = realloc(s->fp, s->fp_cap * sizeof s->fp[0]);
+        assert(s->fp);
+    }
+
+    s->fp[s->fp_n] = (uint32_t) s->stack_n;
+    ++s->fp_n;
+    return T_OK;
 }
 
-static void stack_pop_fp(Stack* s)
+static TYC_RESULT stack_pop_fp(Stack* s)
 {
+    if (s->fp_n == 1)
+        return T_ERR_STACK_FP_UNDERFLOW;
+    s->stack_n = stack_top_fp(s);
+    --s->fp_n;
+    return T_OK;
 }
 
-static uint32_t stack_top_fp(Stack* s)
-{
-}
-
-static uint32_t stack_fp_level(Stack* s)
+static size_t stack_fp_level(Stack* s)
 {
+    return s->fp_n;
 }