rust/src/libsyntax/fold.rs

791 lines
29 KiB
Rust

use codemap::span;
use ast::*;
export ast_fold_precursor;
export ast_fold;
export default_ast_fold;
export make_fold;
export noop_fold_crate;
export noop_fold_item;
export noop_fold_expr;
export noop_fold_pat;
export noop_fold_mod;
export noop_fold_ty;
export noop_fold_block;
export noop_fold_item_underscore;
export wrap;
export fold_ty_param;
export fold_ty_params;
export fold_fn_decl;
export extensions;
trait ast_fold {
fn fold_crate(crate) -> crate;
fn fold_crate_directive(&&v: @crate_directive) -> @crate_directive;
fn fold_view_item(&&v: @view_item) -> @view_item;
fn fold_foreign_item(&&v: @foreign_item) -> @foreign_item;
fn fold_item(&&v: @item) -> Option<@item>;
fn fold_struct_field(&&v: @struct_field) -> @struct_field;
fn fold_item_underscore(item_) -> item_;
fn fold_method(&&v: @method) -> @method;
fn fold_block(blk) -> blk;
fn fold_stmt(&&v: @stmt) -> @stmt;
fn fold_arm(arm) -> arm;
fn fold_pat(&&v: @pat) -> @pat;
fn fold_decl(&&v: @decl) -> @decl;
fn fold_expr(&&v: @expr) -> @expr;
fn fold_ty(&&v: @Ty) -> @Ty;
fn fold_mod(_mod) -> _mod;
fn fold_foreign_mod(foreign_mod) -> foreign_mod;
fn fold_variant(variant) -> variant;
fn fold_ident(&&v: ident) -> ident;
fn fold_path(&&v: @path) -> @path;
fn fold_local(&&v: @local) -> @local;
fn map_exprs(fn@(&&v: @expr) -> @expr, ~[@expr]) -> ~[@expr];
fn new_id(node_id) -> node_id;
fn new_span(span) -> span;
}
// We may eventually want to be able to fold over type parameters, too
type ast_fold_precursor = @{
//unlike the others, item_ is non-trivial
fold_crate: fn@(crate_, span, ast_fold) -> (crate_, span),
fold_crate_directive: fn@(crate_directive_, span,
ast_fold) -> (crate_directive_, span),
fold_view_item: fn@(view_item_, ast_fold) -> view_item_,
fold_foreign_item: fn@(&&v: @foreign_item, ast_fold) -> @foreign_item,
fold_item: fn@(&&v: @item, ast_fold) -> Option<@item>,
fold_struct_field: fn@(&&v: @struct_field, ast_fold) -> @struct_field,
fold_item_underscore: fn@(item_, ast_fold) -> item_,
fold_method: fn@(&&v: @method, ast_fold) -> @method,
fold_block: fn@(blk_, span, ast_fold) -> (blk_, span),
fold_stmt: fn@(stmt_, span, ast_fold) -> (stmt_, span),
fold_arm: fn@(arm, ast_fold) -> arm,
fold_pat: fn@(pat_, span, ast_fold) -> (pat_, span),
fold_decl: fn@(decl_, span, ast_fold) -> (decl_, span),
fold_expr: fn@(expr_, span, ast_fold) -> (expr_, span),
fold_ty: fn@(ty_, span, ast_fold) -> (ty_, span),
fold_mod: fn@(_mod, ast_fold) -> _mod,
fold_foreign_mod: fn@(foreign_mod, ast_fold) -> foreign_mod,
fold_variant: fn@(variant_, span, ast_fold) -> (variant_, span),
fold_ident: fn@(&&v: ident, ast_fold) -> ident,
fold_path: fn@(path, ast_fold) -> path,
fold_local: fn@(local_, span, ast_fold) -> (local_, span),
map_exprs: fn@(fn@(&&v: @expr) -> @expr, ~[@expr]) -> ~[@expr],
new_id: fn@(node_id) -> node_id,
new_span: fn@(span) -> span};
/* some little folds that probably aren't useful to have in ast_fold itself*/
//used in noop_fold_item and noop_fold_crate and noop_fold_crate_directive
fn fold_meta_item_(&&mi: @meta_item, fld: ast_fold) -> @meta_item {
return @{node:
match mi.node {
meta_word(id) => meta_word(id),
meta_list(id, mis) => {
let fold_meta_item = |x|fold_meta_item_(x, fld);
meta_list(/* FIXME: (#2543) */ copy id,
vec::map(mis, |e| fold_meta_item(*e)))
}
meta_name_value(id, s) => {
meta_name_value(id, /* FIXME (#2543) */ copy s)
}
},
span: fld.new_span(mi.span)};
}
//used in noop_fold_item and noop_fold_crate
fn fold_attribute_(at: attribute, fld: ast_fold) ->
attribute {
return {node: {style: at.node.style,
value: *fold_meta_item_(@at.node.value, fld),
is_sugared_doc: at.node.is_sugared_doc },
span: fld.new_span(at.span)};
}
//used in noop_fold_foreign_item and noop_fold_fn_decl
fn fold_arg_(a: arg, fld: ast_fold) -> arg {
return {mode: a.mode,
ty: fld.fold_ty(a.ty),
pat: fld.fold_pat(a.pat),
id: fld.new_id(a.id)};
}
//used in noop_fold_expr, and possibly elsewhere in the future
fn fold_mac_(m: mac, fld: ast_fold) -> mac {
return {node:
match m.node {
mac_invoc(pth, arg, body) => {
mac_invoc(fld.fold_path(pth),
option::map(&arg, |x| fld.fold_expr(*x)), body)
}
mac_invoc_tt(*) => m.node,
mac_ellipsis => mac_ellipsis,
mac_aq(_,_) => /* FIXME (#2543) */ copy m.node,
mac_var(_) => /* FIXME (#2543) */ copy m.node,
},
span: fld.new_span(m.span)};
}
fn fold_fn_decl(decl: ast::fn_decl, fld: ast_fold) -> ast::fn_decl {
return {inputs: vec::map(decl.inputs, |x| fold_arg_(*x, fld) ),
output: fld.fold_ty(decl.output),
cf: decl.cf}
}
fn fold_ty_param_bound(tpb: ty_param_bound, fld: ast_fold) -> ty_param_bound {
ty_param_bound(fld.fold_ty(*tpb))
}
fn fold_ty_param(tp: ty_param, fld: ast_fold) -> ty_param {
{ident: /* FIXME (#2543) */ copy tp.ident,
id: fld.new_id(tp.id),
bounds: @vec::map(*tp.bounds, |x| fold_ty_param_bound(*x, fld) )}
}
fn fold_ty_params(tps: ~[ty_param], fld: ast_fold) -> ~[ty_param] {
vec::map(tps, |x| fold_ty_param(*x, fld) )
}
fn noop_fold_crate(c: crate_, fld: ast_fold) -> crate_ {
let fold_meta_item = |x| fold_meta_item_(x, fld);
let fold_attribute = |x| fold_attribute_(x, fld);
return {
directives: vec::map(c.directives, |x| fld.fold_crate_directive(*x)),
module: fld.fold_mod(c.module),
attrs: vec::map(c.attrs, |x| fold_attribute(*x)),
config: vec::map(c.config, |x| fold_meta_item(*x))
};
}
fn noop_fold_crate_directive(cd: crate_directive_, fld: ast_fold) ->
crate_directive_ {
return match cd {
cdir_src_mod(vis, id, attrs) => {
cdir_src_mod(vis, fld.fold_ident(id),
/* FIXME (#2543) */ copy attrs)
}
cdir_dir_mod(vis, id, cds, attrs) => {
cdir_dir_mod(vis, fld.fold_ident(id),
vec::map(cds, |x| fld.fold_crate_directive(*x)),
/* FIXME (#2543) */ copy attrs)
}
cdir_view_item(vi) => cdir_view_item(fld.fold_view_item(vi)),
cdir_syntax(_) => copy cd
}
}
fn noop_fold_view_item(vi: view_item_, _fld: ast_fold) -> view_item_ {
return /* FIXME (#2543) */ copy vi;
}
fn noop_fold_foreign_item(&&ni: @foreign_item, fld: ast_fold)
-> @foreign_item {
let fold_arg = |x| fold_arg_(x, fld);
let fold_attribute = |x| fold_attribute_(x, fld);
return @{ident: fld.fold_ident(ni.ident),
attrs: vec::map(ni.attrs, |x| fold_attribute(*x)),
node:
match ni.node {
foreign_item_fn(fdec, purity, typms) => {
foreign_item_fn(
{inputs: vec::map(fdec.inputs, |a| fold_arg(*a)),
output: fld.fold_ty(fdec.output),
cf: fdec.cf},
purity,
fold_ty_params(typms, fld))
}
foreign_item_const(t) => {
foreign_item_const(fld.fold_ty(t))
}
},
id: fld.new_id(ni.id),
span: fld.new_span(ni.span),
vis: ni.vis};
}
fn noop_fold_item(&&i: @item, fld: ast_fold) -> Option<@item> {
let fold_attribute = |x| fold_attribute_(x, fld);
return Some(@{ident: fld.fold_ident(i.ident),
attrs: vec::map(i.attrs, |e| fold_attribute(*e)),
id: fld.new_id(i.id),
node: fld.fold_item_underscore(i.node),
vis: i.vis,
span: fld.new_span(i.span)});
}
fn noop_fold_struct_field(&&sf: @struct_field, fld: ast_fold)
-> @struct_field {
@{node: {kind: copy sf.node.kind,
id: sf.node.id,
ty: fld.fold_ty(sf.node.ty)},
span: sf.span}
}
fn noop_fold_item_underscore(i: item_, fld: ast_fold) -> item_ {
return match i {
item_const(t, e) => item_const(fld.fold_ty(t), fld.fold_expr(e)),
item_fn(decl, purity, typms, body) => {
item_fn(fold_fn_decl(decl, fld),
purity,
fold_ty_params(typms, fld),
fld.fold_block(body))
}
item_mod(m) => item_mod(fld.fold_mod(m)),
item_foreign_mod(nm) => item_foreign_mod(fld.fold_foreign_mod(nm)),
item_ty(t, typms) => item_ty(fld.fold_ty(t),
fold_ty_params(typms, fld)),
item_enum(enum_definition, typms) => {
item_enum(ast::enum_def({
variants: vec::map(enum_definition.variants,
|x| fld.fold_variant(*x)),
common: option::map(&enum_definition.common,
|x| fold_struct_def(*x, fld))
}), fold_ty_params(typms, fld))
}
item_class(struct_def, typms) => {
let struct_def = fold_struct_def(struct_def, fld);
item_class(struct_def, /* FIXME (#2543) */ copy typms)
}
item_impl(tps, ifce, ty, ref methods_opt) => {
item_impl(fold_ty_params(tps, fld),
ifce.map(|p| fold_trait_ref(*p, fld)),
fld.fold_ty(ty),
option::map(methods_opt,
|methods| vec::map(
*methods, |x| fld.fold_method(*x))))
}
item_trait(tps, traits, methods) => {
let methods = do methods.map |method| {
match *method {
required(*) => copy *method,
provided(method) => provided(fld.fold_method(method))
}
};
item_trait(fold_ty_params(tps, fld),
vec::map(traits, |p| fold_trait_ref(*p, fld)),
move methods)
}
item_mac(m) => {
// FIXME #2888: we might actually want to do something here.
item_mac(m)
}
};
}
fn fold_struct_def(struct_def: @ast::struct_def, fld: ast_fold)
-> @ast::struct_def {
let dtor = do option::map(&struct_def.dtor) |dtor| {
let dtor_body = fld.fold_block(dtor.node.body);
let dtor_id = fld.new_id(dtor.node.id);
{node: {body: dtor_body,
id: dtor_id,.. dtor.node},
.. *dtor}};
return @{
traits: vec::map(struct_def.traits, |p| fold_trait_ref(*p, fld)),
fields: vec::map(struct_def.fields, |f| fold_struct_field(*f, fld)),
methods: vec::map(struct_def.methods, |m| fld.fold_method(*m)),
dtor: dtor,
ctor_id: option::map(&struct_def.ctor_id, |cid| fld.new_id(*cid))
};
}
fn fold_trait_ref(&&p: @trait_ref, fld: ast_fold) -> @trait_ref {
@{path: fld.fold_path(p.path), ref_id: fld.new_id(p.ref_id),
impl_id: fld.new_id(p.impl_id)}
}
fn fold_struct_field(&&f: @struct_field, fld: ast_fold) -> @struct_field {
@{node: {kind: copy f.node.kind,
id: fld.new_id(f.node.id),
ty: fld.fold_ty(f.node.ty)},
span: fld.new_span(f.span)}
}
fn noop_fold_method(&&m: @method, fld: ast_fold) -> @method {
return @{ident: fld.fold_ident(m.ident),
attrs: /* FIXME (#2543) */ copy m.attrs,
tps: fold_ty_params(m.tps, fld),
self_ty: m.self_ty,
purity: m.purity,
decl: fold_fn_decl(m.decl, fld),
body: fld.fold_block(m.body),
id: fld.new_id(m.id),
span: fld.new_span(m.span),
self_id: fld.new_id(m.self_id),
vis: m.vis};
}
fn noop_fold_block(b: blk_, fld: ast_fold) -> blk_ {
return {view_items: vec::map(b.view_items, |x| fld.fold_view_item(*x)),
stmts: vec::map(b.stmts, |x| fld.fold_stmt(*x)),
expr: option::map(&b.expr, |x| fld.fold_expr(*x)),
id: fld.new_id(b.id),
rules: b.rules};
}
fn noop_fold_stmt(s: stmt_, fld: ast_fold) -> stmt_ {
return match s {
stmt_decl(d, nid) => stmt_decl(fld.fold_decl(d), fld.new_id(nid)),
stmt_expr(e, nid) => stmt_expr(fld.fold_expr(e), fld.new_id(nid)),
stmt_semi(e, nid) => stmt_semi(fld.fold_expr(e), fld.new_id(nid))
};
}
fn noop_fold_arm(a: arm, fld: ast_fold) -> arm {
return {pats: vec::map(a.pats, |x| fld.fold_pat(*x)),
guard: option::map(&a.guard, |x| fld.fold_expr(*x)),
body: fld.fold_block(a.body)};
}
fn noop_fold_pat(p: pat_, fld: ast_fold) -> pat_ {
return match p {
pat_wild => pat_wild,
pat_ident(binding_mode, pth, sub) => {
pat_ident(binding_mode,
fld.fold_path(pth),
option::map(&sub, |x| fld.fold_pat(*x)))
}
pat_lit(e) => pat_lit(fld.fold_expr(e)),
pat_enum(pth, pats) => {
pat_enum(fld.fold_path(pth), option::map(&pats,
|pats| vec::map(*pats, |x| fld.fold_pat(*x))))
}
pat_rec(fields, etc) => {
let mut fs = ~[];
for fields.each |f| {
fs.push({ident: /* FIXME (#2543) */ copy f.ident,
pat: fld.fold_pat(f.pat)});
}
pat_rec(fs, etc)
}
pat_struct(pth, fields, etc) => {
let pth_ = fld.fold_path(pth);
let mut fs = ~[];
for fields.each |f| {
fs.push({ident: /* FIXME (#2543) */ copy f.ident,
pat: fld.fold_pat(f.pat)});
}
pat_struct(pth_, fs, etc)
}
pat_tup(elts) => pat_tup(vec::map(elts, |x| fld.fold_pat(*x))),
pat_box(inner) => pat_box(fld.fold_pat(inner)),
pat_uniq(inner) => pat_uniq(fld.fold_pat(inner)),
pat_region(inner) => pat_region(fld.fold_pat(inner)),
pat_range(e1, e2) => {
pat_range(fld.fold_expr(e1), fld.fold_expr(e2))
}
};
}
fn noop_fold_decl(d: decl_, fld: ast_fold) -> decl_ {
match d {
decl_local(ls) => decl_local(vec::map(ls, |x| fld.fold_local(*x))),
decl_item(it) => match fld.fold_item(it) {
Some(it_folded) => decl_item(it_folded),
None => decl_local(~[])
}
}
}
fn wrap<T>(f: fn@(T, ast_fold) -> T)
-> fn@(T, span, ast_fold) -> (T, span)
{
return fn@(x: T, s: span, fld: ast_fold) -> (T, span) {
(f(x, fld), s)
}
}
fn noop_fold_expr(e: expr_, fld: ast_fold) -> expr_ {
fn fold_field_(field: field, fld: ast_fold) -> field {
return {node:
{mutbl: field.node.mutbl,
ident: fld.fold_ident(field.node.ident),
expr: fld.fold_expr(field.node.expr)},
span: fld.new_span(field.span)};
}
let fold_field = |x| fold_field_(x, fld);
let fold_mac = |x| fold_mac_(x, fld);
return match e {
expr_vstore(e, v) => {
expr_vstore(fld.fold_expr(e), v)
}
expr_vec(exprs, mutt) => {
expr_vec(fld.map_exprs(|x| fld.fold_expr(x), exprs), mutt)
}
expr_repeat(expr, count, mutt) =>
expr_repeat(fld.fold_expr(expr), fld.fold_expr(count), mutt),
expr_rec(fields, maybe_expr) => {
expr_rec(vec::map(fields, |x| fold_field(*x)),
option::map(&maybe_expr, |x| fld.fold_expr(*x)))
}
expr_tup(elts) => expr_tup(vec::map(elts, |x| fld.fold_expr(*x))),
expr_call(f, args, blk) => {
expr_call(fld.fold_expr(f),
fld.map_exprs(|x| fld.fold_expr(x), args),
blk)
}
expr_binary(binop, lhs, rhs) => {
expr_binary(binop, fld.fold_expr(lhs), fld.fold_expr(rhs))
}
expr_unary(binop, ohs) => expr_unary(binop, fld.fold_expr(ohs)),
expr_loop_body(f) => expr_loop_body(fld.fold_expr(f)),
expr_do_body(f) => expr_do_body(fld.fold_expr(f)),
expr_lit(_) => copy e,
expr_cast(expr, ty) => expr_cast(fld.fold_expr(expr), ty),
expr_addr_of(m, ohs) => expr_addr_of(m, fld.fold_expr(ohs)),
expr_if(cond, tr, fl) => {
expr_if(fld.fold_expr(cond), fld.fold_block(tr),
option::map(&fl, |x| fld.fold_expr(*x)))
}
expr_while(cond, body) => {
expr_while(fld.fold_expr(cond), fld.fold_block(body))
}
expr_loop(body, opt_ident) => {
expr_loop(fld.fold_block(body),
option::map(&opt_ident, |x| fld.fold_ident(*x)))
}
expr_match(expr, arms) => {
expr_match(fld.fold_expr(expr),
vec::map(arms, |x| fld.fold_arm(*x)))
}
expr_fn(proto, decl, body, captures) => {
expr_fn(proto, fold_fn_decl(decl, fld),
fld.fold_block(body),
@((*captures).map(|cap_item| {
@({id: fld.new_id(cap_item.id),
..**cap_item})})))
}
expr_fn_block(decl, body, captures) => {
expr_fn_block(fold_fn_decl(decl, fld), fld.fold_block(body),
@((*captures).map(|cap_item| {
@({id: fld.new_id(cap_item.id),
..**cap_item})})))
}
expr_block(blk) => expr_block(fld.fold_block(blk)),
expr_copy(e) => expr_copy(fld.fold_expr(e)),
expr_unary_move(e) => expr_unary_move(fld.fold_expr(e)),
expr_assign(el, er) => {
expr_assign(fld.fold_expr(el), fld.fold_expr(er))
}
expr_swap(el, er) => {
expr_swap(fld.fold_expr(el), fld.fold_expr(er))
}
expr_assign_op(op, el, er) => {
expr_assign_op(op, fld.fold_expr(el), fld.fold_expr(er))
}
expr_field(el, id, tys) => {
expr_field(fld.fold_expr(el), fld.fold_ident(id),
vec::map(tys, |x| fld.fold_ty(*x)))
}
expr_index(el, er) => {
expr_index(fld.fold_expr(el), fld.fold_expr(er))
}
expr_path(pth) => expr_path(fld.fold_path(pth)),
expr_fail(e) => expr_fail(option::map(&e, |x| fld.fold_expr(*x))),
expr_break(opt_ident) =>
expr_break(option::map(&opt_ident, |x| fld.fold_ident(*x))),
expr_again(opt_ident) =>
expr_again(option::map(&opt_ident, |x| fld.fold_ident(*x))),
expr_ret(e) => expr_ret(option::map(&e, |x| fld.fold_expr(*x))),
expr_log(i, lv, e) => expr_log(i, fld.fold_expr(lv),
fld.fold_expr(e)),
expr_assert(e) => expr_assert(fld.fold_expr(e)),
expr_mac(mac) => expr_mac(fold_mac(mac)),
expr_struct(path, fields, maybe_expr) => {
expr_struct(fld.fold_path(path),
vec::map(fields, |x| fold_field(*x)),
option::map(&maybe_expr, |x| fld.fold_expr(*x)))
},
expr_paren(ex) => expr_paren(fld.fold_expr(ex))
}
}
fn noop_fold_ty(t: ty_, fld: ast_fold) -> ty_ {
let fold_mac = |x| fold_mac_(x, fld);
fn fold_mt(mt: mt, fld: ast_fold) -> mt {
{ty: fld.fold_ty(mt.ty), mutbl: mt.mutbl}
}
fn fold_field(f: ty_field, fld: ast_fold) -> ty_field {
{node: {ident: fld.fold_ident(f.node.ident),
mt: fold_mt(f.node.mt, fld)},
span: fld.new_span(f.span)}
}
match t {
ty_nil | ty_bot | ty_infer => copy t,
ty_box(mt) => ty_box(fold_mt(mt, fld)),
ty_uniq(mt) => ty_uniq(fold_mt(mt, fld)),
ty_vec(mt) => ty_vec(fold_mt(mt, fld)),
ty_ptr(mt) => ty_ptr(fold_mt(mt, fld)),
ty_rptr(region, mt) => ty_rptr(region, fold_mt(mt, fld)),
ty_rec(fields) => ty_rec(vec::map(fields, |f| fold_field(*f, fld))),
ty_fn(f) =>
ty_fn(@TyFn {
proto: f.proto,
purity: f.purity,
region: f.region,
onceness: f.onceness,
bounds: @vec::map(*f.bounds, |x| fold_ty_param_bound(*x, fld)),
decl: fold_fn_decl(f.decl, fld)
}),
ty_tup(tys) => ty_tup(vec::map(tys, |ty| fld.fold_ty(*ty))),
ty_path(path, id) => ty_path(fld.fold_path(path), fld.new_id(id)),
ty_fixed_length_vec(mt, vs) =>
ty_fixed_length_vec(fold_mt(mt, fld), vs),
ty_mac(mac) => ty_mac(fold_mac(mac))
}
}
// ...nor do modules
fn noop_fold_mod(m: _mod, fld: ast_fold) -> _mod {
return {view_items: vec::map(m.view_items, |x| fld.fold_view_item(*x)),
items: vec::filter_map(m.items, |x| fld.fold_item(*x))};
}
fn noop_fold_foreign_mod(nm: foreign_mod, fld: ast_fold) -> foreign_mod {
return {sort: nm.sort,
view_items: vec::map(nm.view_items, |x| fld.fold_view_item(*x)),
items: vec::map(nm.items, |x| fld.fold_foreign_item(*x))}
}
fn noop_fold_variant(v: variant_, fld: ast_fold) -> variant_ {
fn fold_variant_arg_(va: variant_arg, fld: ast_fold) -> variant_arg {
return {ty: fld.fold_ty(va.ty), id: fld.new_id(va.id)};
}
let fold_variant_arg = |x| fold_variant_arg_(x, fld);
let kind;
match v.kind {
tuple_variant_kind(variant_args) =>
kind = tuple_variant_kind(vec::map(variant_args,
|x| fold_variant_arg(*x))),
struct_variant_kind(struct_def) => {
let dtor = do option::map(&struct_def.dtor) |dtor| {
let dtor_body = fld.fold_block(dtor.node.body);
let dtor_id = fld.new_id(dtor.node.id);
{node: {body: dtor_body,
id: dtor_id,.. dtor.node},
.. *dtor}};
kind = struct_variant_kind(@{
traits: ~[],
fields: vec::map(struct_def.fields,
|f| fld.fold_struct_field(*f)),
methods: vec::map(struct_def.methods,
|m| fld.fold_method(*m)),
dtor: dtor,
ctor_id: option::map(&struct_def.ctor_id, |c| fld.new_id(*c))
})
}
enum_variant_kind(enum_definition) => {
let variants = vec::map(enum_definition.variants,
|x| fld.fold_variant(*x));
let common = option::map(&enum_definition.common,
|x| fold_struct_def(*x, fld));
kind = enum_variant_kind(ast::enum_def({ variants: variants,
common: common }));
}
}
let fold_attribute = |x| fold_attribute_(x, fld);
let attrs = vec::map(v.attrs, |x| fold_attribute(*x));
let de = match v.disr_expr {
Some(e) => Some(fld.fold_expr(e)),
None => None
};
return {name: /* FIXME (#2543) */ copy v.name,
attrs: attrs,
kind: kind,
id: fld.new_id(v.id),
disr_expr: de,
vis: v.vis};
}
fn noop_fold_ident(&&i: ident, _fld: ast_fold) -> ident {
return /* FIXME (#2543) */ copy i;
}
fn noop_fold_path(&&p: path, fld: ast_fold) -> path {
return {span: fld.new_span(p.span), global: p.global,
idents: vec::map(p.idents, |x| fld.fold_ident(*x)),
rp: p.rp,
types: vec::map(p.types, |x| fld.fold_ty(*x))};
}
fn noop_fold_local(l: local_, fld: ast_fold) -> local_ {
return {is_mutbl: l.is_mutbl,
ty: fld.fold_ty(l.ty),
pat: fld.fold_pat(l.pat),
init: l.init.map(|e| fld.fold_expr(*e)),
id: fld.new_id(l.id)};
}
/* temporarily eta-expand because of a compiler bug with using `fn<T>` as a
value */
fn noop_map_exprs(f: fn@(&&v: @expr) -> @expr, es: ~[@expr]) -> ~[@expr] {
return vec::map(es, |x| f(*x));
}
fn noop_id(i: node_id) -> node_id { return i; }
fn noop_span(sp: span) -> span { return sp; }
fn default_ast_fold() -> ast_fold_precursor {
return @{fold_crate: wrap(noop_fold_crate),
fold_crate_directive: wrap(noop_fold_crate_directive),
fold_view_item: noop_fold_view_item,
fold_foreign_item: noop_fold_foreign_item,
fold_item: noop_fold_item,
fold_struct_field: noop_fold_struct_field,
fold_item_underscore: noop_fold_item_underscore,
fold_method: noop_fold_method,
fold_block: wrap(noop_fold_block),
fold_stmt: wrap(noop_fold_stmt),
fold_arm: noop_fold_arm,
fold_pat: wrap(noop_fold_pat),
fold_decl: wrap(noop_fold_decl),
fold_expr: wrap(noop_fold_expr),
fold_ty: wrap(noop_fold_ty),
fold_mod: noop_fold_mod,
fold_foreign_mod: noop_fold_foreign_mod,
fold_variant: wrap(noop_fold_variant),
fold_ident: noop_fold_ident,
fold_path: noop_fold_path,
fold_local: wrap(noop_fold_local),
map_exprs: noop_map_exprs,
new_id: noop_id,
new_span: noop_span};
}
impl ast_fold_precursor: ast_fold {
/* naturally, a macro to write these would be nice */
fn fold_crate(c: crate) -> crate {
let (n, s) = self.fold_crate(c.node, c.span, self as ast_fold);
return {node: n, span: self.new_span(s)};
}
fn fold_crate_directive(&&c: @crate_directive) -> @crate_directive {
let (n, s) = self.fold_crate_directive(c.node, c.span,
self as ast_fold);
return @{node: n,
span: self.new_span(s)};
}
fn fold_view_item(&&x: @view_item) ->
@view_item {
return @{node: self.fold_view_item(x.node, self as ast_fold),
attrs: vec::map(x.attrs, |a|
fold_attribute_(*a, self as ast_fold)),
vis: x.vis,
span: self.new_span(x.span)};
}
fn fold_foreign_item(&&x: @foreign_item)
-> @foreign_item {
return self.fold_foreign_item(x, self as ast_fold);
}
fn fold_item(&&i: @item) -> Option<@item> {
return self.fold_item(i, self as ast_fold);
}
fn fold_struct_field(&&sf: @struct_field) -> @struct_field {
@{node: {kind: copy sf.node.kind,
id: sf.node.id,
ty: (self as ast_fold).fold_ty(sf.node.ty)},
span: self.new_span(sf.span)}
}
fn fold_item_underscore(i: item_) ->
item_ {
return self.fold_item_underscore(i, self as ast_fold);
}
fn fold_method(&&x: @method)
-> @method {
return self.fold_method(x, self as ast_fold);
}
fn fold_block(x: blk) -> blk {
let (n, s) = self.fold_block(x.node, x.span, self as ast_fold);
return {node: n, span: self.new_span(s)};
}
fn fold_stmt(&&x: @stmt) -> @stmt {
let (n, s) = self.fold_stmt(x.node, x.span, self as ast_fold);
return @{node: n, span: self.new_span(s)};
}
fn fold_arm(x: arm) -> arm {
return self.fold_arm(x, self as ast_fold);
}
fn fold_pat(&&x: @pat) -> @pat {
let (n, s) = self.fold_pat(x.node, x.span, self as ast_fold);
return @{id: self.new_id(x.id),
node: n,
span: self.new_span(s)};
}
fn fold_decl(&&x: @decl) -> @decl {
let (n, s) = self.fold_decl(x.node, x.span, self as ast_fold);
return @{node: n, span: self.new_span(s)};
}
fn fold_expr(&&x: @expr) -> @expr {
let (n, s) = self.fold_expr(x.node, x.span, self as ast_fold);
return @{id: self.new_id(x.id),
callee_id: self.new_id(x.callee_id),
node: n,
span: self.new_span(s)};
}
fn fold_ty(&&x: @Ty) -> @Ty {
let (n, s) = self.fold_ty(x.node, x.span, self as ast_fold);
return @{id: self.new_id(x.id), node: n, span: self.new_span(s)};
}
fn fold_mod(x: _mod) -> _mod {
return self.fold_mod(x, self as ast_fold);
}
fn fold_foreign_mod(x: foreign_mod) ->
foreign_mod {
return self.fold_foreign_mod(x, self as ast_fold);
}
fn fold_variant(x: variant) ->
variant {
let (n, s) = self.fold_variant(x.node, x.span, self as ast_fold);
return {node: n, span: self.new_span(s)};
}
fn fold_ident(&&x: ident) -> ident {
return self.fold_ident(x, self as ast_fold);
}
fn fold_path(&&x: @path) -> @path {
@self.fold_path(*x, self as ast_fold)
}
fn fold_local(&&x: @local) -> @local {
let (n, s) = self.fold_local(x.node, x.span, self as ast_fold);
return @{node: n, span: self.new_span(s)};
}
fn map_exprs(f: fn@(&&v: @expr) -> @expr, e: ~[@expr]) -> ~[@expr] {
self.map_exprs(f, e)
}
fn new_id(node_id: ast::node_id) -> node_id {
self.new_id(node_id)
}
fn new_span(span: span) -> span {
self.new_span(span)
}
}
impl ast_fold {
fn fold_attributes(attrs: ~[attribute]) -> ~[attribute] {
attrs.map(|x| fold_attribute_(*x, self))
}
}
fn make_fold(afp: ast_fold_precursor) -> ast_fold {
afp as ast_fold
}
//
// Local Variables:
// mode: rust
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End:
//