#[derive(Debug, Clone, PartialEq)]
pub struct Program {
    pub decls: Vec<Decl>,
}

#[derive(Debug, Clone, PartialEq)]
pub enum Decl {
    Struct(StructDecl),
    Fn(FnDecl),
    TypeAlias(String, TypeExpr),
}

#[derive(Debug, Clone, PartialEq)]
pub struct StructDecl {
    pub name: String,
    pub fields: Vec<FieldDecl>,
}

#[derive(Debug, Clone, PartialEq)]
pub struct FieldDecl {
    pub name: String,
    pub ty: TypeExpr,
}

#[derive(Debug, Clone, PartialEq)]
pub struct FnDecl {
    pub is_pure: bool,
    pub is_gpu: bool,
    pub name: String,
    pub params: Vec<Param>,
    pub return_type: TypeExpr,
    pub body: Block,
}

#[derive(Debug, Clone, PartialEq)]
pub struct Param {
    pub name: String,
    pub ty: TypeExpr,
}

#[derive(Debug, Clone, PartialEq)]
pub struct Block {
    pub statements: Vec<Stmt>,
}

#[derive(Debug, Clone, PartialEq)]
pub enum Stmt {
    Return(Expr),
    ExprStmt(Expr),
    LetBind(String, Expr),
}

#[derive(Debug, Clone, PartialEq)]
pub enum Expr {
    Binary(Box<Expr>, BinaryOp, Box<Expr>),
    Literal(String),
    Identifier(String),
}

#[derive(Debug, Clone, PartialEq, Eq)]
pub enum BinaryOp {
    Add,
    Sub,
    Mul,
    Div,
    Gt,
    Lt,
    Eq,
}

#[derive(Debug, Clone, PartialEq)]
pub enum TypeExpr {
    BaseType(String),
    Refined(Box<TypeExpr>, String, Box<Expr>),
}