#pragma once
typedef struct Expr Expr;

typedef enum Expr_Kind{
  EK_None,
  EK_Atom,
  EK_Unary, 
  EK_Binary, 
  EK_Ternary,
  EK_Cast,
  EK_List, 
  EK_Call, 
  EK_Index,
} Expr_Kind;

struct Expr {
  Expr_Kind kind;
  Token *token;
  Expr  *next;
  union {
    struct {
      AST_Node *type;
      Expr* expr;
    } cast;
    struct {
      Expr *first;
      Expr *last;
    } list;
    struct {
      Expr *atom;
      Expr *list;
    } call;
    struct {
      Expr *atom;
      Expr *index;
    } index;
    struct {
      Expr* expr;
    } unary;
    struct {
      Expr* left;
      Expr* right;
    } binary;
    struct {
      Expr* cond;
      Expr* on_true;
      Expr* on_false;
    } ternary;
  };
};