rust/src/libsyntax/ext/deriving/generic/ty.rs

271 lines
8.4 KiB
Rust

// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
/*!
A mini version of ast::Ty, which is easier to use, and features an
explicit `Self` type to use when specifying impls to be derived.
*/
use ast;
use ast::{P,Expr,Generics,Ident};
use ext::base::ExtCtxt;
use ext::build::AstBuilder;
use codemap::{Span,respan};
use owned_slice::OwnedSlice;
use parse::token::special_idents;
use std::gc::Gc;
/// The types of pointers
#[deriving(Clone)]
pub enum PtrTy<'a> {
/// &'lifetime mut
Borrowed(Option<&'a str>, ast::Mutability),
}
/// A path, e.g. `::std::option::Option::<int>` (global). Has support
/// for type parameters and a lifetime.
#[deriving(Clone)]
pub struct Path<'a> {
pub path: Vec<&'a str> ,
pub lifetime: Option<&'a str>,
pub params: Vec<Box<Ty<'a>>>,
pub global: bool,
}
impl<'a> Path<'a> {
pub fn new<'r>(path: Vec<&'r str> ) -> Path<'r> {
Path::new_(path, None, Vec::new(), true)
}
pub fn new_local<'r>(path: &'r str) -> Path<'r> {
Path::new_(vec!( path ), None, Vec::new(), false)
}
pub fn new_<'r>(path: Vec<&'r str> ,
lifetime: Option<&'r str>,
params: Vec<Box<Ty<'r>>>,
global: bool)
-> Path<'r> {
Path {
path: path,
lifetime: lifetime,
params: params,
global: global
}
}
pub fn to_ty(&self,
cx: &ExtCtxt,
span: Span,
self_ty: Ident,
self_generics: &Generics)
-> P<ast::Ty> {
cx.ty_path(self.to_path(cx, span, self_ty, self_generics), None)
}
pub fn to_path(&self,
cx: &ExtCtxt,
span: Span,
self_ty: Ident,
self_generics: &Generics)
-> ast::Path {
let idents = self.path.iter().map(|s| cx.ident_of(*s)).collect();
let lt = mk_lifetimes(cx, span, &self.lifetime);
let tys = self.params.iter().map(|t| t.to_ty(cx, span, self_ty, self_generics)).collect();
cx.path_all(span, self.global, idents, lt, tys)
}
}
/// A type. Supports pointers (except for *), Self, and literals
#[deriving(Clone)]
pub enum Ty<'a> {
Self,
/// &/Box/ Ty
Ptr(Box<Ty<'a>>, PtrTy<'a>),
/// mod::mod::Type<[lifetime], [Params...]>, including a plain type
/// parameter, and things like `int`
Literal(Path<'a>),
/// includes unit
Tuple(Vec<Ty<'a>> )
}
pub fn borrowed_ptrty<'r>() -> PtrTy<'r> {
Borrowed(None, ast::MutImmutable)
}
pub fn borrowed<'r>(ty: Box<Ty<'r>>) -> Ty<'r> {
Ptr(ty, borrowed_ptrty())
}
pub fn borrowed_explicit_self<'r>() -> Option<Option<PtrTy<'r>>> {
Some(Some(borrowed_ptrty()))
}
pub fn borrowed_self<'r>() -> Ty<'r> {
borrowed(box Self)
}
pub fn nil_ty<'r>() -> Ty<'r> {
Tuple(Vec::new())
}
fn mk_lifetime(cx: &ExtCtxt, span: Span, lt: &Option<&str>) -> Option<ast::Lifetime> {
match *lt {
Some(ref s) => Some(cx.lifetime(span, cx.ident_of(*s).name)),
None => None
}
}
fn mk_lifetimes(cx: &ExtCtxt, span: Span, lt: &Option<&str>) -> Vec<ast::Lifetime> {
match *lt {
Some(ref s) => vec!(cx.lifetime(span, cx.ident_of(*s).name)),
None => vec!()
}
}
impl<'a> Ty<'a> {
pub fn to_ty(&self,
cx: &ExtCtxt,
span: Span,
self_ty: Ident,
self_generics: &Generics)
-> P<ast::Ty> {
match *self {
Ptr(ref ty, ref ptr) => {
let raw_ty = ty.to_ty(cx, span, self_ty, self_generics);
match *ptr {
Borrowed(ref lt, mutbl) => {
let lt = mk_lifetime(cx, span, lt);
cx.ty_rptr(span, raw_ty, lt, mutbl)
}
}
}
Literal(ref p) => { p.to_ty(cx, span, self_ty, self_generics) }
Self => {
cx.ty_path(self.to_path(cx, span, self_ty, self_generics), None)
}
Tuple(ref fields) => {
let ty = if fields.is_empty() {
ast::TyNil
} else {
ast::TyTup(fields.iter()
.map(|f| f.to_ty(cx, span, self_ty, self_generics))
.collect())
};
cx.ty(span, ty)
}
}
}
pub fn to_path(&self,
cx: &ExtCtxt,
span: Span,
self_ty: Ident,
self_generics: &Generics)
-> ast::Path {
match *self {
Self => {
let self_params = self_generics.ty_params.map(|ty_param| {
cx.ty_ident(span, ty_param.ident)
});
let lifetimes = self_generics.lifetimes.clone();
cx.path_all(span, false, vec!(self_ty), lifetimes,
self_params.into_vec())
}
Literal(ref p) => {
p.to_path(cx, span, self_ty, self_generics)
}
Ptr(..) => { cx.span_bug(span, "pointer in a path in generic `deriving`") }
Tuple(..) => { cx.span_bug(span, "tuple in a path in generic `deriving`") }
}
}
}
fn mk_ty_param(cx: &ExtCtxt, span: Span, name: &str,
bounds: &[Path], unbound: Option<ast::TyParamBound>,
self_ident: Ident, self_generics: &Generics) -> ast::TyParam {
let bounds =
bounds.iter().map(|b| {
let path = b.to_path(cx, span, self_ident, self_generics);
cx.typarambound(path)
}).collect();
cx.typaram(span, cx.ident_of(name), bounds, unbound, None)
}
fn mk_generics(lifetimes: Vec<ast::Lifetime>, ty_params: Vec<ast::TyParam> ) -> Generics {
Generics {
lifetimes: lifetimes,
ty_params: OwnedSlice::from_vec(ty_params)
}
}
/// Lifetimes and bounds on type parameters
#[deriving(Clone)]
pub struct LifetimeBounds<'a> {
pub lifetimes: Vec<&'a str>,
pub bounds: Vec<(&'a str, Option<ast::TyParamBound>, Vec<Path<'a>>)>,
}
impl<'a> LifetimeBounds<'a> {
pub fn empty() -> LifetimeBounds<'a> {
LifetimeBounds {
lifetimes: Vec::new(), bounds: Vec::new()
}
}
pub fn to_generics(&self,
cx: &ExtCtxt,
span: Span,
self_ty: Ident,
self_generics: &Generics)
-> Generics {
let lifetimes = self.lifetimes.iter().map(|lt| {
cx.lifetime(span, cx.ident_of(*lt).name)
}).collect();
let ty_params = self.bounds.iter().map(|t| {
match t {
&(ref name, ref unbound, ref bounds) => {
mk_ty_param(cx,
span,
*name,
bounds.as_slice(),
unbound.clone(),
self_ty,
self_generics)
}
}
}).collect();
mk_generics(lifetimes, ty_params)
}
}
pub fn get_explicit_self(cx: &ExtCtxt, span: Span, self_ptr: &Option<PtrTy>)
-> (Gc<Expr>, ast::ExplicitSelf) {
// this constructs a fresh `self` path, which will match the fresh `self` binding
// created below.
let self_path = cx.expr_self(span);
match *self_ptr {
None => {
(self_path, respan(span, ast::SelfValue(special_idents::self_)))
}
Some(ref ptr) => {
let self_ty = respan(
span,
match *ptr {
Borrowed(ref lt, mutbl) => {
let lt = lt.map(|s| cx.lifetime(span, cx.ident_of(s).name));
ast::SelfRegion(lt, mutbl, special_idents::self_)
}
});
let self_expr = cx.expr_deref(span, self_path);
(self_expr, self_ty)
}
}
}