5 files changed, 44 insertions, 6 deletions
diff --git a/src/include/aplwc.h b/src/include/aplwc.h
index 5ec3761..61c7e9f 100644
--- a/src/include/aplwc.h
+++ b/src/include/aplwc.h
@@ -16,6 +16,7 @@ enum aplwc_rc {
 
 struct aplwc;
 struct aplwc_line;
+struct aplwc_value;
 
 enum aplwc_rc aplwc_new(struct aplwc **, uint8_t *, size_t);
 void aplwc_destroy(struct aplwc *);
@@ -24,7 +25,8 @@ const char *aplwc_errstr(struct aplwc *);
 enum aplwc_rc aplwc_last_error(struct aplwc *);
 struct aplwc_line *aplwc_read(struct aplwc *, const char *);
 void aplwc_free_line(struct aplwc_line *);
-enum aplwc_rc aplwc_eval(struct aplwc_line *);
+struct aplwc_value *aplwc_eval(struct aplwc_line *);
+void aplwc_free_value(struct aplwc_value *);
 
 #define APLWC_MIN_MEM (64)
 
diff --git a/src/lib/aplwc_internal.h b/src/lib/aplwc_internal.h
index 833a351..4ad30f8 100644
--- a/src/lib/aplwc_internal.h
+++ b/src/lib/aplwc_internal.h
@@ -53,8 +53,17 @@ struct token_list {
 	struct token tokens[1];
 };
 
+enum value_tag {
+	VALUE_NUMBER
+};
+
+struct aplwc_value {
+	struct aplwc *aplwc;
+	enum value_tag tag;
+};
+
 /* eval.c */
-void eval_line(struct aplwc_line *);
+struct aplwc_value *eval_line(struct aplwc_line *);
 
 /* memory.c */
 struct memory memory_init(uint8_t *, size_t);
@@ -62,10 +71,12 @@ struct aplwc *memory_alloc_aplwc(struct memory *);
 struct aplwc_line *memory_alloc_aplwc_line(struct memory *);
 struct string *memory_alloc_string(struct memory *, size_t);
 struct token_list *memory_alloc_token_list(struct memory *, size_t);
+struct aplwc_value *memory_alloc_aplwc_value(struct memory *);
 void memory_free_aplwc(struct memory *, struct aplwc *);
 void memory_free_aplwc_line(struct memory *, struct aplwc_line *);
 void memory_free_string(struct memory *, struct string *);
 void memory_free_token_list(struct memory *, struct token_list *);
+void memory_free_aplwc_value(struct memory *, struct aplwc_value *);
 
 /* string.c */
 struct string *chars_to_string(struct aplwc *, const char *);
diff --git a/src/lib/eval.c b/src/lib/eval.c
index 89bdf59..07bbedd 100644
--- a/src/lib/eval.c
+++ b/src/lib/eval.c
@@ -1,7 +1,9 @@
 #include "aplwc_internal.h"
 
-void
+struct aplwc_value *
 eval_line(struct aplwc_line *line)
 {
+	assert(line->aplwc->last_error == APLWC_OK);
 	line->aplwc->last_error = APLWC_NOT_YET_IMPLEMENTED;
+	return NULL;
 }
diff --git a/src/lib/main.c b/src/lib/main.c
index 9335bf0..7456958 100644
--- a/src/lib/main.c
+++ b/src/lib/main.c
@@ -99,10 +99,17 @@ aplwc_free_line(struct aplwc_line *line)
 	memory_free_aplwc_line(&line->aplwc->memory, line);
 }
 
-enum aplwc_rc
+struct aplwc_value *
 aplwc_eval(struct aplwc_line *line)
 {
 	line->aplwc->last_error = APLWC_OK;
-	eval_line(line);
-	return line->aplwc->last_error;
+	return eval_line(line);
+}
+
+void
+aplwc_free_value(struct aplwc_value *value)
+{
+	if(value == NULL)
+		return;
+	memory_free_aplwc_value(&value->aplwc->memory, value);
 }
diff --git a/src/lib/memory.c b/src/lib/memory.c
index 41ac90d..f34ff43 100644
--- a/src/lib/memory.c
+++ b/src/lib/memory.c
@@ -102,3 +102,19 @@ memory_free_token_list(struct memory *m, struct token_list *p)
 	UNUSED_PARAMETER(m);
 	UNUSED_PARAMETER(p);
 }
+
+struct aplwc_value *
+memory_alloc_aplwc_value(struct memory *m)
+{
+	struct aplwc_value *p;
+
+	p = alloc(m, sizeof(struct aplwc_value), alignof(struct aplwc_value));
+	return p;
+}
+
+void
+memory_free_aplwc_value(struct memory *m, struct aplwc_value *p)
+{
+	UNUSED_PARAMETER(m);
+	UNUSED_PARAMETER(p);
+}