1 files changed, 77 insertions, 0 deletions
diff --git a/ast.h b/ast.h
new file mode 100644
index 0000000..c82f089
--- /dev/null
+++ b/ast.h
@@ -0,0 +1,77 @@
+#ifndef AST_H
+#define AST_H
+
+struct stmt_node;
+struct expr_node;
+
+struct type_node {
+    char* type;
+};
+
+struct var_decl_node {
+    struct type_node type;
+    char* ident;
+
+    struct var_decl_node* next;
+};
+
+struct group_node {
+    struct stmt_node* body_head;
+};
+
+struct fn_decl_node {
+    struct type_node return_type;
+    char* name;
+    struct var_decl_node* args_head;
+    struct group_node body;
+};
+
+struct return_node {
+    struct expr_node* ret_val; /* null to return void */
+};
+
+struct int_lit_node {
+    long long val;
+};
+
+struct expr_node {
+    enum {
+        EXPR_EMPTY,
+        EXPR_VAR_DECL,
+        EXPR_RETURN,
+        EXPR_INT_LIT,
+    } type;
+    union {
+        struct var_decl_node _var_decl;
+        struct return_node _return;
+        struct int_lit_node _int_lit;
+    } as;
+};
+
+struct stmt_node {
+    enum {
+        STMT_EXPR,
+        STMT_GROUP,
+    } type;
+    union {
+        struct expr_node _expr;
+        struct group_node _group;
+    } as;
+
+    struct stmt_node* next;
+};
+
+struct root_node {
+    enum {
+        ROOT_FN_DECL,
+    } type;
+    union {
+        struct fn_decl_node _fn_decl;
+    } as;
+
+    struct root_node* next;
+};
+
+void ast_destroy(struct root_node* head);
+
+#endif