ast.h

typedef enum{
    RETURN,
    BINARY_OP
} ast_node_type;

typedef struct{
    ast_node_type type;
} ast_node;

typedef struct{
    ast_node node;
    ast_node* left;
    ast_node* right;
} ast_node_binary_op;

typedef struct{
    ast_node node;
    ast_node* value;
} ast_node_return;