rust/src/libsyntax/fold.rs

1021 lines
34 KiB
Rust

// Copyright 2012 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.
use ast::*;
use ast;
use codemap::{span, spanned};
use parse::token;
use opt_vec::OptVec;
pub trait ast_fold {
fn fold_crate(@self, &Crate) -> Crate;
fn fold_view_item(@self, &view_item) -> view_item;
fn fold_foreign_item(@self, @foreign_item) -> @foreign_item;
fn fold_item(@self, @item) -> Option<@item>;
fn fold_struct_field(@self, @struct_field) -> @struct_field;
fn fold_item_underscore(@self, &item_) -> item_;
fn fold_method(@self, @method) -> @method;
fn fold_block(@self, &Block) -> Block;
fn fold_stmt(@self, &stmt) -> Option<@stmt>;
fn fold_arm(@self, &arm) -> arm;
fn fold_pat(@self, @pat) -> @pat;
fn fold_decl(@self, @decl) -> Option<@decl>;
fn fold_expr(@self, @expr) -> @expr;
fn fold_ty(@self, &Ty) -> Ty;
fn fold_mod(@self, &_mod) -> _mod;
fn fold_foreign_mod(@self, &foreign_mod) -> foreign_mod;
fn fold_variant(@self, &variant) -> variant;
fn fold_ident(@self, ident) -> ident;
fn fold_path(@self, &Path) -> Path;
fn fold_local(@self, @Local) -> @Local;
fn map_exprs(@self, @fn(@expr) -> @expr, &[@expr]) -> ~[@expr];
fn new_id(@self, NodeId) -> NodeId;
fn new_span(@self, span) -> span;
}
// We may eventually want to be able to fold over type parameters, too
pub struct AstFoldFns {
//unlike the others, item_ is non-trivial
fold_crate: @fn(&Crate, @ast_fold) -> Crate,
fold_view_item: @fn(&view_item_, @ast_fold) -> view_item_,
fold_foreign_item: @fn(@foreign_item, @ast_fold) -> @foreign_item,
fold_item: @fn(@item, @ast_fold) -> Option<@item>,
fold_struct_field: @fn(@struct_field, @ast_fold) -> @struct_field,
fold_item_underscore: @fn(&item_, @ast_fold) -> item_,
fold_method: @fn(@method, @ast_fold) -> @method,
fold_block: @fn(&Block, @ast_fold) -> Block,
fold_stmt: @fn(&stmt_, span, @ast_fold) -> (Option<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) -> (Option<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(ident, @ast_fold) -> ident,
fold_path: @fn(&Path, @ast_fold) -> Path,
fold_local: @fn(@Local, @ast_fold) -> @Local,
map_exprs: @fn(@fn(@expr) -> @expr, &[@expr]) -> ~[@expr],
new_id: @fn(NodeId) -> NodeId,
new_span: @fn(span) -> span
}
pub type ast_fold_fns = @AstFoldFns;
/* 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: @MetaItem, fld: @ast_fold) -> @MetaItem {
@spanned {
node:
match mi.node {
MetaWord(id) => MetaWord(id),
MetaList(id, ref mis) => {
let fold_meta_item = |x| fold_meta_item_(x, fld);
MetaList(
id,
mis.map(|e| fold_meta_item(*e))
)
}
MetaNameValue(id, s) => MetaNameValue(id, 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 {
spanned {
span: fld.new_span(at.span),
node: ast::Attribute_ {
style: at.node.style,
value: fold_meta_item_(at.node.value, fld),
is_sugared_doc: at.node.is_sugared_doc
}
}
}
//used in noop_fold_foreign_item and noop_fold_fn_decl
fn fold_arg_(a: arg, fld: @ast_fold) -> arg {
ast::arg {
is_mutbl: a.is_mutbl,
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 {
spanned {
node: match m.node {
mac_invoc_tt(ref p,ref tts) =>
mac_invoc_tt(fld.fold_path(p),
fold_tts(*tts,fld))
},
span: fld.new_span(m.span)
}
}
fn fold_tts(tts : &[token_tree], fld: @ast_fold) -> ~[token_tree] {
do tts.map |tt| {
match *tt {
tt_tok(span, ref tok) =>
tt_tok(span,maybe_fold_ident(tok,fld)),
tt_delim(ref tts) =>
tt_delim(@mut fold_tts(**tts, fld)),
tt_seq(span, ref pattern, ref sep, is_optional) =>
tt_seq(span,
@mut fold_tts(**pattern, fld),
sep.map(|tok|maybe_fold_ident(tok,fld)),
is_optional),
tt_nonterminal(sp,ref ident) =>
tt_nonterminal(sp,fld.fold_ident(*ident))
}
}
}
// apply ident folder if it's an ident, otherwise leave it alone
fn maybe_fold_ident(t: &token::Token, fld: @ast_fold) -> token::Token {
match *t {
token::IDENT(id,followed_by_colons) =>
token::IDENT(fld.fold_ident(id),followed_by_colons),
_ => (*t).clone()
}
}
pub fn fold_fn_decl(decl: &ast::fn_decl, fld: @ast_fold) -> ast::fn_decl {
ast::fn_decl {
inputs: decl.inputs.map(|x| fold_arg_(/*bad*/ (*x).clone(), fld)),
output: fld.fold_ty(&decl.output),
cf: decl.cf,
}
}
fn fold_ty_param_bound(tpb: &TyParamBound, fld: @ast_fold) -> TyParamBound {
match *tpb {
TraitTyParamBound(ref ty) => TraitTyParamBound(fold_trait_ref(ty, fld)),
RegionTyParamBound => RegionTyParamBound
}
}
pub fn fold_ty_param(tp: TyParam,
fld: @ast_fold) -> TyParam {
TyParam {ident: tp.ident,
id: fld.new_id(tp.id),
bounds: tp.bounds.map(|x| fold_ty_param_bound(x, fld))}
}
pub fn fold_ty_params(tps: &OptVec<TyParam>,
fld: @ast_fold) -> OptVec<TyParam> {
let tps = /*bad*/ (*tps).clone();
tps.map_consume(|tp| fold_ty_param(tp, fld))
}
pub fn fold_lifetime(l: &Lifetime,
fld: @ast_fold) -> Lifetime {
Lifetime {id: fld.new_id(l.id),
span: fld.new_span(l.span),
ident: l.ident}
}
pub fn fold_lifetimes(lts: &OptVec<Lifetime>,
fld: @ast_fold) -> OptVec<Lifetime> {
lts.map(|l| fold_lifetime(l, fld))
}
pub fn fold_generics(generics: &Generics, fld: @ast_fold) -> Generics {
Generics {ty_params: fold_ty_params(&generics.ty_params, fld),
lifetimes: fold_lifetimes(&generics.lifetimes, fld)}
}
pub 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);
Crate {
module: fld.fold_mod(&c.module),
attrs: c.attrs.map(|x| fold_attribute(*x)),
config: c.config.map(|x| fold_meta_item(*x)),
span: fld.new_span(c.span),
}
}
fn noop_fold_view_item(vi: &view_item_, _fld: @ast_fold) -> view_item_ {
return /* FIXME (#2543) */ (*vi).clone();
}
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);
@ast::foreign_item {
ident: fld.fold_ident(ni.ident),
attrs: ni.attrs.map(|x| fold_attribute(*x)),
node:
match ni.node {
foreign_item_fn(ref fdec, purity, ref generics) => {
foreign_item_fn(
ast::fn_decl {
inputs: fdec.inputs.map(|a|
fold_arg(/*bad*/(*a).clone())),
output: fld.fold_ty(&fdec.output),
cf: fdec.cf,
},
purity,
fold_generics(generics, fld))
}
foreign_item_static(ref t, m) => {
foreign_item_static(fld.fold_ty(t), m)
}
},
id: fld.new_id(ni.id),
span: fld.new_span(ni.span),
vis: ni.vis,
}
}
pub fn noop_fold_item(i: @item, fld: @ast_fold) -> Option<@item> {
let fold_attribute = |x| fold_attribute_(x, fld);
Some(@ast::item { ident: fld.fold_ident(i.ident),
attrs: i.attrs.map(|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 {
let fold_attribute = |x| fold_attribute_(x, fld);
@spanned {
node: ast::struct_field_ {
kind: sf.node.kind,
id: sf.node.id,
ty: fld.fold_ty(&sf.node.ty),
attrs: sf.node.attrs.map(|e| fold_attribute(*e))
},
span: sf.span
}
}
pub fn noop_fold_item_underscore(i: &item_, fld: @ast_fold) -> item_ {
match *i {
item_static(ref t, m, e) => item_static(fld.fold_ty(t), m, fld.fold_expr(e)),
item_fn(ref decl, purity, abi, ref generics, ref body) => {
item_fn(
fold_fn_decl(decl, fld),
purity,
abi,
fold_generics(generics, fld),
fld.fold_block(body)
)
}
item_mod(ref m) => item_mod(fld.fold_mod(m)),
item_foreign_mod(ref nm) => {
item_foreign_mod(fld.fold_foreign_mod(nm))
}
item_ty(ref t, ref generics) => {
item_ty(fld.fold_ty(t), fold_generics(generics, fld))
}
item_enum(ref enum_definition, ref generics) => {
item_enum(
ast::enum_def {
variants: do enum_definition.variants.map |x| {
fld.fold_variant(x)
},
},
fold_generics(generics, fld))
}
item_struct(ref struct_def, ref generics) => {
let struct_def = fold_struct_def(*struct_def, fld);
item_struct(struct_def, /* FIXME (#2543) */ (*generics).clone())
}
item_impl(ref generics, ref ifce, ref ty, ref methods) => {
item_impl(
fold_generics(generics, fld),
ifce.map(|p| fold_trait_ref(p, fld)),
fld.fold_ty(ty),
methods.map(|x| fld.fold_method(*x))
)
}
item_trait(ref generics, ref traits, ref methods) => {
let methods = do methods.map |method| {
match *method {
required(*) => (*method).clone(),
provided(method) => provided(fld.fold_method(method))
}
};
item_trait(
fold_generics(generics, fld),
traits.map(|p| fold_trait_ref(p, fld)),
methods
)
}
item_mac(ref m) => {
// FIXME #2888: we might actually want to do something here.
// ... okay, we're doing something. It would probably be nicer
// to add something to the ast_fold trait, but I'll defer
// that work.
item_mac(fold_mac_(m,fld))
}
}
}
fn fold_struct_def(struct_def: @ast::struct_def, fld: @ast_fold)
-> @ast::struct_def {
@ast::struct_def {
fields: struct_def.fields.map(|f| fold_struct_field(*f, fld)),
ctor_id: struct_def.ctor_id.map(|cid| fld.new_id(*cid)),
}
}
fn fold_trait_ref(p: &trait_ref, fld: @ast_fold) -> trait_ref {
ast::trait_ref {
path: fld.fold_path(&p.path),
ref_id: fld.new_id(p.ref_id),
}
}
fn fold_struct_field(f: @struct_field, fld: @ast_fold) -> @struct_field {
@spanned {
node: ast::struct_field_ {
kind: f.node.kind,
id: fld.new_id(f.node.id),
ty: fld.fold_ty(&f.node.ty),
attrs: /* FIXME (#2543) */ f.node.attrs.clone(),
},
span: fld.new_span(f.span),
}
}
fn noop_fold_method(m: @method, fld: @ast_fold) -> @method {
@ast::method {
ident: fld.fold_ident(m.ident),
attrs: /* FIXME (#2543) */ m.attrs.clone(),
generics: fold_generics(&m.generics, fld),
explicit_self: m.explicit_self,
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,
}
}
pub fn noop_fold_block(b: &Block, fld: @ast_fold) -> Block {
let view_items = b.view_items.map(|x| fld.fold_view_item(x));
let mut stmts = ~[];
for b.stmts.iter().advance |stmt| {
match fld.fold_stmt(*stmt) {
None => {}
Some(stmt) => stmts.push(stmt)
}
}
ast::Block {
view_items: view_items,
stmts: stmts,
expr: b.expr.map(|x| fld.fold_expr(*x)),
id: fld.new_id(b.id),
rules: b.rules,
span: b.span,
}
}
fn noop_fold_stmt(s: &stmt_, fld: @ast_fold) -> Option<stmt_> {
let fold_mac = |x| fold_mac_(x, fld);
match *s {
stmt_decl(d, nid) => {
match fld.fold_decl(d) {
Some(d) => Some(stmt_decl(d, fld.new_id(nid))),
None => None,
}
}
stmt_expr(e, nid) => {
Some(stmt_expr(fld.fold_expr(e), fld.new_id(nid)))
}
stmt_semi(e, nid) => {
Some(stmt_semi(fld.fold_expr(e), fld.new_id(nid)))
}
stmt_mac(ref mac, semi) => Some(stmt_mac(fold_mac(mac), semi))
}
}
fn noop_fold_arm(a: &arm, fld: @ast_fold) -> arm {
arm {
pats: a.pats.map(|x| fld.fold_pat(*x)),
guard: a.guard.map(|x| fld.fold_expr(*x)),
body: fld.fold_block(&a.body),
}
}
pub fn noop_fold_pat(p: &pat_, fld: @ast_fold) -> pat_ {
match *p {
pat_wild => pat_wild,
pat_ident(binding_mode, ref pth, ref sub) => {
pat_ident(
binding_mode,
fld.fold_path(pth),
sub.map(|x| fld.fold_pat(*x))
)
}
pat_lit(e) => pat_lit(fld.fold_expr(e)),
pat_enum(ref pth, ref pats) => {
pat_enum(
fld.fold_path(pth),
pats.map(|pats| pats.map(|x| fld.fold_pat(*x)))
)
}
pat_struct(ref pth, ref fields, etc) => {
let pth_ = fld.fold_path(pth);
let fs = do fields.map |f| {
ast::field_pat {
ident: f.ident,
pat: fld.fold_pat(f.pat)
}
};
pat_struct(pth_, fs, etc)
}
pat_tup(ref elts) => pat_tup(elts.map(|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))
},
pat_vec(ref before, ref slice, ref after) => {
pat_vec(
before.map(|x| fld.fold_pat(*x)),
slice.map(|x| fld.fold_pat(*x)),
after.map(|x| fld.fold_pat(*x))
)
}
}
}
fn noop_fold_decl(d: &decl_, fld: @ast_fold) -> Option<decl_> {
match *d {
decl_local(ref l) => Some(decl_local(fld.fold_local(*l))),
decl_item(it) => {
match fld.fold_item(it) {
Some(it_folded) => Some(decl_item(it_folded)),
None => None,
}
}
}
}
pub fn wrap<T>(f: @fn(&T, @ast_fold) -> T)
-> @fn(&T, span, @ast_fold) -> (T, span) {
let result: @fn(&T, span, @ast_fold) -> (T, span) = |x, s, fld| {
(f(x, fld), s)
};
result
}
pub fn noop_fold_expr(e: &expr_, fld: @ast_fold) -> expr_ {
fn fold_field_(field: Field, fld: @ast_fold) -> Field {
ast::Field {
ident: fld.fold_ident(field.ident),
expr: fld.fold_expr(field.expr),
span: fld.new_span(field.span),
}
}
let fold_field = |x| fold_field_(x, fld);
let fold_mac = |x| fold_mac_(x, fld);
match *e {
expr_vstore(e, v) => {
expr_vstore(fld.fold_expr(e), v)
}
expr_vec(ref 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_tup(ref elts) => expr_tup(elts.map(|x| fld.fold_expr(*x))),
expr_call(f, ref args, blk) => {
expr_call(
fld.fold_expr(f),
fld.map_exprs(|x| fld.fold_expr(x), *args),
blk
)
}
expr_method_call(callee_id, f, i, ref tps, ref args, blk) => {
expr_method_call(
fld.new_id(callee_id),
fld.fold_expr(f),
fld.fold_ident(i),
tps.map(|x| fld.fold_ty(x)),
fld.map_exprs(|x| fld.fold_expr(x), *args),
blk
)
}
expr_binary(callee_id, binop, lhs, rhs) => {
expr_binary(
fld.new_id(callee_id),
binop,
fld.fold_expr(lhs),
fld.fold_expr(rhs)
)
}
expr_unary(callee_id, binop, ohs) => {
expr_unary(
fld.new_id(callee_id),
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(_) => (*e).clone(),
expr_cast(expr, ref ty) => {
expr_cast(fld.fold_expr(expr), (*ty).clone())
}
expr_addr_of(m, ohs) => expr_addr_of(m, fld.fold_expr(ohs)),
expr_if(cond, ref tr, fl) => {
expr_if(
fld.fold_expr(cond),
fld.fold_block(tr),
fl.map(|x| fld.fold_expr(*x))
)
}
expr_while(cond, ref body) => {
expr_while(fld.fold_expr(cond), fld.fold_block(body))
}
expr_for_loop(pat, iter, ref body) => {
expr_for_loop(fld.fold_pat(pat),
fld.fold_expr(iter),
fld.fold_block(body))
}
expr_loop(ref body, opt_ident) => {
expr_loop(
fld.fold_block(body),
opt_ident.map(|x| fld.fold_ident(*x))
)
}
expr_match(expr, ref arms) => {
expr_match(
fld.fold_expr(expr),
arms.map(|x| fld.fold_arm(x))
)
}
expr_fn_block(ref decl, ref body) => {
expr_fn_block(
fold_fn_decl(decl, fld),
fld.fold_block(body)
)
}
expr_block(ref blk) => expr_block(fld.fold_block(blk)),
expr_assign(el, er) => {
expr_assign(fld.fold_expr(el), fld.fold_expr(er))
}
expr_assign_op(callee_id, op, el, er) => {
expr_assign_op(
fld.new_id(callee_id),
op,
fld.fold_expr(el),
fld.fold_expr(er)
)
}
expr_field(el, id, ref tys) => {
expr_field(
fld.fold_expr(el), fld.fold_ident(id),
tys.map(|x| fld.fold_ty(x))
)
}
expr_index(callee_id, el, er) => {
expr_index(
fld.new_id(callee_id),
fld.fold_expr(el),
fld.fold_expr(er)
)
}
expr_path(ref pth) => expr_path(fld.fold_path(pth)),
expr_self => expr_self,
expr_break(ref opt_ident) => {
expr_break(opt_ident.map(|x| fld.fold_ident(*x)))
}
expr_again(ref opt_ident) => {
expr_again(opt_ident.map(|x| fld.fold_ident(*x)))
}
expr_ret(ref e) => {
expr_ret(e.map(|x| fld.fold_expr(*x)))
}
expr_log(lv, e) => {
expr_log(
fld.fold_expr(lv),
fld.fold_expr(e)
)
}
expr_inline_asm(ref a) => {
expr_inline_asm(inline_asm {
inputs: a.inputs.map(|&(c, in)| (c, fld.fold_expr(in))),
outputs: a.outputs.map(|&(c, out)| (c, fld.fold_expr(out))),
.. (*a).clone()
})
}
expr_mac(ref mac) => expr_mac(fold_mac(mac)),
expr_struct(ref path, ref fields, maybe_expr) => {
expr_struct(
fld.fold_path(path),
fields.map(|x| fold_field(*x)),
maybe_expr.map(|x| fld.fold_expr(*x))
)
},
expr_paren(ex) => expr_paren(fld.fold_expr(ex))
}
}
pub 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 {
mt {
ty: ~fld.fold_ty(mt.ty),
mutbl: mt.mutbl,
}
}
fn fold_field(f: TypeField, fld: @ast_fold) -> TypeField {
ast::TypeField {
ident: fld.fold_ident(f.ident),
mt: fold_mt(&f.mt, fld),
span: fld.new_span(f.span),
}
}
fn fold_opt_bounds(b: &Option<OptVec<TyParamBound>>, fld: @ast_fold)
-> Option<OptVec<TyParamBound>> {
do b.map |bounds| {
do bounds.map |bound| { fold_ty_param_bound(bound, fld) }
}
}
match *t {
ty_nil | ty_bot | ty_infer => (*t).clone(),
ty_box(ref mt) => ty_box(fold_mt(mt, fld)),
ty_uniq(ref mt) => ty_uniq(fold_mt(mt, fld)),
ty_vec(ref mt) => ty_vec(fold_mt(mt, fld)),
ty_ptr(ref mt) => ty_ptr(fold_mt(mt, fld)),
ty_rptr(region, ref mt) => ty_rptr(region, fold_mt(mt, fld)),
ty_closure(ref f) => {
ty_closure(@TyClosure {
sigil: f.sigil,
purity: f.purity,
region: f.region,
onceness: f.onceness,
bounds: fold_opt_bounds(&f.bounds, fld),
decl: fold_fn_decl(&f.decl, fld),
lifetimes: f.lifetimes.clone(),
})
}
ty_bare_fn(ref f) => {
ty_bare_fn(@TyBareFn {
lifetimes: f.lifetimes.clone(),
purity: f.purity,
abis: f.abis,
decl: fold_fn_decl(&f.decl, fld)
})
}
ty_tup(ref tys) => ty_tup(tys.map(|ty| fld.fold_ty(ty))),
ty_path(ref path, ref bounds, id) =>
ty_path(fld.fold_path(path), fold_opt_bounds(bounds, fld), fld.new_id(id)),
ty_fixed_length_vec(ref mt, e) => {
ty_fixed_length_vec(
fold_mt(mt, fld),
fld.fold_expr(e)
)
}
ty_mac(ref mac) => ty_mac(fold_mac(mac))
}
}
// ...nor do modules
pub fn noop_fold_mod(m: &_mod, fld: @ast_fold) -> _mod {
ast::_mod {
view_items: m.view_items.iter().transform(|x| fld.fold_view_item(x)).collect(),
items: m.items.iter().filter_map(|x| fld.fold_item(*x)).collect(),
}
}
fn noop_fold_foreign_mod(nm: &foreign_mod, fld: @ast_fold) -> foreign_mod {
ast::foreign_mod {
sort: nm.sort,
abis: nm.abis,
view_items: nm.view_items.iter().transform(|x| fld.fold_view_item(x)).collect(),
items: nm.items.iter().transform(|x| fld.fold_foreign_item(*x)).collect(),
}
}
fn noop_fold_variant(v: &variant_, fld: @ast_fold) -> variant_ {
fn fold_variant_arg_(va: variant_arg, fld: @ast_fold) -> variant_arg {
ast::variant_arg { 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(ref variant_args) => {
kind = tuple_variant_kind(do variant_args.map |x| {
fold_variant_arg(/*bad*/ (*x).clone())
})
}
struct_variant_kind(struct_def) => {
kind = struct_variant_kind(@ast::struct_def {
fields: struct_def.fields.iter()
.transform(|f| fld.fold_struct_field(*f)).collect(),
ctor_id: struct_def.ctor_id.map(|c| fld.new_id(*c))
})
}
}
let fold_attribute = |x| fold_attribute_(x, fld);
let attrs = v.attrs.map(|x| fold_attribute(*x));
let de = match v.disr_expr {
Some(e) => Some(fld.fold_expr(e)),
None => None
};
ast::variant_ {
name: 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 {
i
}
fn noop_fold_path(p: &Path, fld: @ast_fold) -> Path {
ast::Path {
span: fld.new_span(p.span),
global: p.global,
idents: p.idents.map(|x| fld.fold_ident(*x)),
rp: p.rp,
types: p.types.map(|x| fld.fold_ty(x)),
}
}
fn noop_fold_local(l: @Local, fld: @ast_fold) -> @Local {
@Local {
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),
span: fld.new_span(l.span),
}
}
/* temporarily eta-expand because of a compiler bug with using `fn<T>` as a
value */
fn noop_map_exprs(f: @fn(@expr) -> @expr, es: &[@expr]) -> ~[@expr] {
es.map(|x| f(*x))
}
fn noop_id(i: NodeId) -> NodeId { return i; }
fn noop_span(sp: span) -> span { return sp; }
pub fn default_ast_fold() -> ast_fold_fns {
@AstFoldFns {
fold_crate: noop_fold_crate,
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: noop_fold_block,
fold_stmt: |x, s, fld| (noop_fold_stmt(x, fld), s),
fold_arm: noop_fold_arm,
fold_pat: wrap(noop_fold_pat),
fold_decl: |x, s, fld| (noop_fold_decl(x, fld), s),
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: noop_fold_local,
map_exprs: noop_map_exprs,
new_id: noop_id,
new_span: noop_span,
}
}
impl ast_fold for AstFoldFns {
/* naturally, a macro to write these would be nice */
fn fold_crate(@self, c: &Crate) -> Crate {
(self.fold_crate)(c, self as @ast_fold)
}
fn fold_view_item(@self, x: &view_item) -> view_item {
ast::view_item {
node: (self.fold_view_item)(&x.node, self as @ast_fold),
attrs: x.attrs.iter().transform(|a| fold_attribute_(*a, self as @ast_fold)).collect(),
vis: x.vis,
span: (self.new_span)(x.span),
}
}
fn fold_foreign_item(@self, x: @foreign_item) -> @foreign_item {
(self.fold_foreign_item)(x, self as @ast_fold)
}
fn fold_item(@self, i: @item) -> Option<@item> {
(self.fold_item)(i, self as @ast_fold)
}
fn fold_struct_field(@self, sf: @struct_field) -> @struct_field {
@spanned {
node: ast::struct_field_ {
kind: sf.node.kind,
id: sf.node.id,
ty: self.fold_ty(&sf.node.ty),
attrs: sf.node.attrs.clone(),
},
span: (self.new_span)(sf.span),
}
}
fn fold_item_underscore(@self, i: &item_) -> item_ {
(self.fold_item_underscore)(i, self as @ast_fold)
}
fn fold_method(@self, x: @method) -> @method {
(self.fold_method)(x, self as @ast_fold)
}
fn fold_block(@self, x: &Block) -> Block {
(self.fold_block)(x, self as @ast_fold)
}
fn fold_stmt(@self, x: &stmt) -> Option<@stmt> {
let (n_opt, s) = (self.fold_stmt)(&x.node, x.span, self as @ast_fold);
match n_opt {
Some(n) => Some(@spanned { node: n, span: (self.new_span)(s) }),
None => None,
}
}
fn fold_arm(@self, x: &arm) -> arm {
(self.fold_arm)(x, self as @ast_fold)
}
fn fold_pat(@self, x: @pat) -> @pat {
let (n, s) = (self.fold_pat)(&x.node, x.span, self as @ast_fold);
@pat {
id: (self.new_id)(x.id),
node: n,
span: (self.new_span)(s),
}
}
fn fold_decl(@self, x: @decl) -> Option<@decl> {
let (n_opt, s) = (self.fold_decl)(&x.node, x.span, self as @ast_fold);
match n_opt {
Some(n) => Some(@spanned { node: n, span: (self.new_span)(s) }),
None => None,
}
}
fn fold_expr(@self, x: @expr) -> @expr {
let (n, s) = (self.fold_expr)(&x.node, x.span, self as @ast_fold);
@expr {
id: (self.new_id)(x.id),
node: n,
span: (self.new_span)(s),
}
}
fn fold_ty(@self, x: &Ty) -> Ty {
let (n, s) = (self.fold_ty)(&x.node, x.span, self as @ast_fold);
Ty {
id: (self.new_id)(x.id),
node: n,
span: (self.new_span)(s),
}
}
fn fold_mod(@self, x: &_mod) -> _mod {
(self.fold_mod)(x, self as @ast_fold)
}
fn fold_foreign_mod(@self, x: &foreign_mod) -> foreign_mod {
(self.fold_foreign_mod)(x, self as @ast_fold)
}
fn fold_variant(@self, x: &variant) -> variant {
let (n, s) = (self.fold_variant)(&x.node, x.span, self as @ast_fold);
spanned { node: n, span: (self.new_span)(s) }
}
fn fold_ident(@self, x: ident) -> ident {
(self.fold_ident)(x, self as @ast_fold)
}
fn fold_path(@self, x: &Path) -> Path {
(self.fold_path)(x, self as @ast_fold)
}
fn fold_local(@self, x: @Local) -> @Local {
(self.fold_local)(x, self as @ast_fold)
}
fn map_exprs(@self,
f: @fn(@expr) -> @expr,
e: &[@expr])
-> ~[@expr] {
(self.map_exprs)(f, e)
}
fn new_id(@self, node_id: ast::NodeId) -> NodeId {
(self.new_id)(node_id)
}
fn new_span(@self, span: span) -> span {
(self.new_span)(span)
}
}
pub trait AstFoldExtensions {
fn fold_attributes(&self, attrs: ~[Attribute]) -> ~[Attribute];
}
impl AstFoldExtensions for @ast_fold {
fn fold_attributes(&self, attrs: ~[Attribute]) -> ~[Attribute] {
attrs.map(|x| fold_attribute_(*x, *self))
}
}
pub fn make_fold(afp: ast_fold_fns) -> @ast_fold {
afp as @ast_fold
}
#[cfg(test)]
mod test {
use ast;
use util::parser_testing::{string_to_crate, matches_codepattern};
use parse::token;
use print::pprust;
use super::*;
// taken from expand
// given a function from idents to idents, produce
// an ast_fold that applies that function:
pub fn fun_to_ident_folder(f: @fn(ast::ident)->ast::ident) -> @ast_fold{
let afp = default_ast_fold();
let f_pre = @AstFoldFns{
fold_ident : |id, _| f(id),
.. *afp
};
make_fold(f_pre)
}
// this version doesn't care about getting comments or docstrings in.
fn fake_print_crate(s: @pprust::ps, crate: &ast::Crate) {
pprust::print_mod(s, &crate.module, crate.attrs);
}
// change every identifier to "zz"
pub fn to_zz() -> @fn(ast::ident)->ast::ident {
let zz_id = token::str_to_ident("zz");
|_id| {zz_id}
}
// maybe add to expand.rs...
macro_rules! assert_pred (
($pred:expr, $predname:expr, $a:expr , $b:expr) => (
{
let pred_val = $pred;
let a_val = $a;
let b_val = $b;
if !(pred_val(a_val,b_val)) {
fail!("expected args satisfying %s, got %? and %?",
$predname, a_val, b_val);
}
}
)
)
// make sure idents get transformed everywhere
#[test] fn ident_transformation () {
let zz_fold = fun_to_ident_folder(to_zz());
let ast = string_to_crate(@"#[a] mod b {fn c (d : e, f : g) {h!(i,j,k);l;m}}");
assert_pred!(matches_codepattern,
"matches_codepattern",
pprust::to_str(&zz_fold.fold_crate(ast),fake_print_crate,
token::get_ident_interner()),
~"#[a]mod zz{fn zz(zz:zz,zz:zz){zz!(zz,zz,zz);zz;zz}}");
}
// even inside macro defs....
#[test] fn ident_transformation_in_defs () {
let zz_fold = fun_to_ident_folder(to_zz());
let ast = string_to_crate(@"macro_rules! a {(b $c:expr $(d $e:token)f+
=> (g $(d $d $e)+))} ");
assert_pred!(matches_codepattern,
"matches_codepattern",
pprust::to_str(&zz_fold.fold_crate(ast),fake_print_crate,
token::get_ident_interner()),
~"zz!zz((zz$zz:zz$(zz $zz:zz)zz+=>(zz$(zz$zz$zz)+)))");
}
}