rust/src/libsyntax/ast_util.rs

1171 lines
35 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 ast_util;
use codemap::{span, dummy_sp};
use opt_vec;
use parse::token;
use visit::{SimpleVisitor, SimpleVisitorVisitor, Visitor};
use visit;
use std::hashmap::HashMap;
use std::int;
use std::local_data;
use std::num;
use std::option;
pub fn path_name_i(idents: &[ident]) -> ~str {
// FIXME: Bad copies (#2543 -- same for everything else that says "bad")
idents.map(|i| token::interner_get(i.name)).connect("::")
}
pub fn path_to_ident(p: &Path) -> ident {
*p.idents.last()
}
pub fn local_def(id: NodeId) -> def_id {
ast::def_id { crate: LOCAL_CRATE, node: id }
}
pub fn is_local(did: ast::def_id) -> bool { did.crate == LOCAL_CRATE }
pub fn stmt_id(s: &stmt) -> NodeId {
match s.node {
stmt_decl(_, id) => id,
stmt_expr(_, id) => id,
stmt_semi(_, id) => id,
stmt_mac(*) => fail!("attempted to analyze unexpanded stmt")
}
}
pub fn variant_def_ids(d: def) -> Option<(def_id, def_id)> {
match d {
def_variant(enum_id, var_id) => {
Some((enum_id, var_id))
}
_ => None
}
}
pub fn def_id_of_def(d: def) -> def_id {
match d {
def_fn(id, _) | def_static_method(id, _, _) | def_mod(id) |
def_foreign_mod(id) | def_static(id, _) |
def_variant(_, id) | def_ty(id) | def_ty_param(id, _) |
def_use(id) | def_struct(id) | def_trait(id) | def_method(id, _) => {
id
}
def_arg(id, _) | def_local(id, _) | def_self(id, _) | def_self_ty(id)
| def_upvar(id, _, _, _) | def_binding(id, _) | def_region(id)
| def_typaram_binder(id) | def_label(id) => {
local_def(id)
}
def_prim_ty(_) => fail!()
}
}
pub fn binop_to_str(op: binop) -> ~str {
match op {
add => return ~"+",
subtract => return ~"-",
mul => return ~"*",
div => return ~"/",
rem => return ~"%",
and => return ~"&&",
or => return ~"||",
bitxor => return ~"^",
bitand => return ~"&",
bitor => return ~"|",
shl => return ~"<<",
shr => return ~">>",
eq => return ~"==",
lt => return ~"<",
le => return ~"<=",
ne => return ~"!=",
ge => return ~">=",
gt => return ~">"
}
}
pub fn binop_to_method_name(op: binop) -> Option<~str> {
match op {
add => return Some(~"add"),
subtract => return Some(~"sub"),
mul => return Some(~"mul"),
div => return Some(~"div"),
rem => return Some(~"rem"),
bitxor => return Some(~"bitxor"),
bitand => return Some(~"bitand"),
bitor => return Some(~"bitor"),
shl => return Some(~"shl"),
shr => return Some(~"shr"),
lt => return Some(~"lt"),
le => return Some(~"le"),
ge => return Some(~"ge"),
gt => return Some(~"gt"),
eq => return Some(~"eq"),
ne => return Some(~"ne"),
and | or => return None
}
}
pub fn lazy_binop(b: binop) -> bool {
match b {
and => true,
or => true,
_ => false
}
}
pub fn is_shift_binop(b: binop) -> bool {
match b {
shl => true,
shr => true,
_ => false
}
}
pub fn unop_to_str(op: unop) -> ~str {
match op {
box(mt) => if mt == m_mutbl { ~"@mut " } else { ~"@" },
uniq => ~"~",
deref => ~"*",
not => ~"!",
neg => ~"-"
}
}
pub fn is_path(e: @expr) -> bool {
return match e.node { expr_path(_) => true, _ => false };
}
pub fn int_ty_to_str(t: int_ty) -> ~str {
match t {
ty_char => ~"u8", // ???
ty_i => ~"",
ty_i8 => ~"i8",
ty_i16 => ~"i16",
ty_i32 => ~"i32",
ty_i64 => ~"i64"
}
}
pub fn int_ty_max(t: int_ty) -> u64 {
match t {
ty_i8 => 0x80u64,
ty_i16 => 0x8000u64,
ty_i | ty_char | ty_i32 => 0x80000000u64, // actually ni about ty_i
ty_i64 => 0x8000000000000000u64
}
}
pub fn uint_ty_to_str(t: uint_ty) -> ~str {
match t {
ty_u => ~"u",
ty_u8 => ~"u8",
ty_u16 => ~"u16",
ty_u32 => ~"u32",
ty_u64 => ~"u64"
}
}
pub fn uint_ty_max(t: uint_ty) -> u64 {
match t {
ty_u8 => 0xffu64,
ty_u16 => 0xffffu64,
ty_u | ty_u32 => 0xffffffffu64, // actually ni about ty_u
ty_u64 => 0xffffffffffffffffu64
}
}
pub fn float_ty_to_str(t: float_ty) -> ~str {
match t { ty_f => ~"f", ty_f32 => ~"f32", ty_f64 => ~"f64" }
}
pub fn is_call_expr(e: @expr) -> bool {
match e.node { expr_call(*) => true, _ => false }
}
pub fn block_from_expr(e: @expr) -> Block {
let mut blk = default_block(~[], option::Some::<@expr>(e), e.id);
blk.span = e.span;
return blk;
}
pub fn default_block(
stmts1: ~[@stmt],
expr1: Option<@expr>,
id1: NodeId
) -> Block {
ast::Block {
view_items: ~[],
stmts: stmts1,
expr: expr1,
id: id1,
rules: DefaultBlock,
span: dummy_sp(),
}
}
pub fn ident_to_path(s: span, i: ident) -> Path {
ast::Path { span: s,
global: false,
idents: ~[i],
rp: None,
types: ~[] }
}
pub fn ident_to_pat(id: NodeId, s: span, i: ident) -> @pat {
@ast::pat { id: id,
node: pat_ident(bind_infer, ident_to_path(s, i), None),
span: s }
}
pub fn is_unguarded(a: &arm) -> bool {
match a.guard {
None => true,
_ => false
}
}
pub fn unguarded_pat(a: &arm) -> Option<~[@pat]> {
if is_unguarded(a) {
Some(/* FIXME (#2543) */ a.pats.clone())
} else {
None
}
}
pub fn public_methods(ms: ~[@method]) -> ~[@method] {
do ms.consume_iter().filter |m| {
match m.vis {
public => true,
_ => false
}
}.collect()
}
// extract a TypeMethod from a trait_method. if the trait_method is
// a default, pull out the useful fields to make a TypeMethod
pub fn trait_method_to_ty_method(method: &trait_method) -> TypeMethod {
match *method {
required(ref m) => (*m).clone(),
provided(ref m) => {
TypeMethod {
ident: m.ident,
attrs: m.attrs.clone(),
purity: m.purity,
decl: m.decl.clone(),
generics: m.generics.clone(),
explicit_self: m.explicit_self,
id: m.id,
span: m.span,
}
}
}
}
pub fn split_trait_methods(trait_methods: &[trait_method])
-> (~[TypeMethod], ~[@method]) {
let mut reqd = ~[];
let mut provd = ~[];
for trt_method in trait_methods.iter() {
match *trt_method {
required(ref tm) => reqd.push((*tm).clone()),
provided(m) => provd.push(m)
}
};
(reqd, provd)
}
pub fn struct_field_visibility(field: ast::struct_field) -> visibility {
match field.node.kind {
ast::named_field(_, visibility) => visibility,
ast::unnamed_field => ast::public
}
}
pub trait inlined_item_utils {
fn ident(&self) -> ident;
fn id(&self) -> ast::NodeId;
fn accept<E: Clone>(&self, e: E, v: @Visitor<E>);
}
impl inlined_item_utils for inlined_item {
fn ident(&self) -> ident {
match *self {
ii_item(i) => i.ident,
ii_foreign(i) => i.ident,
ii_method(_, _, m) => m.ident,
}
}
fn id(&self) -> ast::NodeId {
match *self {
ii_item(i) => i.id,
ii_foreign(i) => i.id,
ii_method(_, _, m) => m.id,
}
}
fn accept<E: Clone>(&self, e: E, v: @Visitor<E>) {
match *self {
ii_item(i) => v.visit_item(i, e),
ii_foreign(i) => v.visit_foreign_item(i, e),
ii_method(_, _, m) => visit::visit_method_helper(v, m, e),
}
}
}
/* True if d is either a def_self, or a chain of def_upvars
referring to a def_self */
pub fn is_self(d: ast::def) -> bool {
match d {
def_self(*) => true,
def_upvar(_, d, _, _) => is_self(*d),
_ => false
}
}
/// Maps a binary operator to its precedence
pub fn operator_prec(op: ast::binop) -> uint {
match op {
// 'as' sits here with 12
mul | div | rem => 11u,
add | subtract => 10u,
shl | shr => 9u,
bitand => 8u,
bitxor => 7u,
bitor => 6u,
lt | le | ge | gt => 4u,
eq | ne => 3u,
and => 2u,
or => 1u
}
}
/// Precedence of the `as` operator, which is a binary operator
/// not appearing in the prior table.
pub static as_prec: uint = 12u;
pub fn empty_generics() -> Generics {
Generics {lifetimes: opt_vec::Empty,
ty_params: opt_vec::Empty}
}
// ______________________________________________________________________
// Enumerating the IDs which appear in an AST
#[deriving(Encodable, Decodable)]
pub struct id_range {
min: NodeId,
max: NodeId,
}
impl id_range {
pub fn max() -> id_range {
id_range {
min: int::max_value,
max: int::min_value,
}
}
pub fn empty(&self) -> bool {
self.min >= self.max
}
pub fn add(&mut self, id: NodeId) {
self.min = num::min(self.min, id);
self.max = num::max(self.max, id + 1);
}
}
struct IdVisitor {
visit_callback: @fn(NodeId),
pass_through_items: bool,
visited_outermost: bool,
}
impl IdVisitor {
fn visit_generics_helper(@mut self, generics: &Generics) {
for type_parameter in generics.ty_params.iter() {
(self.visit_callback)(type_parameter.id)
}
for lifetime in generics.lifetimes.iter() {
(self.visit_callback)(lifetime.id)
}
}
}
impl Visitor<()> for IdVisitor {
fn visit_mod(@mut self,
module: &_mod,
_span: span,
node_id: NodeId,
env: ()) {
(self.visit_callback)(node_id);
visit::visit_mod(self as @Visitor<()>, module, env)
}
fn visit_view_item(@mut self, view_item: &view_item, env: ()) {
match view_item.node {
view_item_extern_mod(_, _, node_id) => {
(self.visit_callback)(node_id)
}
view_item_use(ref view_paths) => {
for view_path in view_paths.iter() {
match view_path.node {
view_path_simple(_, _, node_id) |
view_path_glob(_, node_id) => {
(self.visit_callback)(node_id)
}
view_path_list(_, ref paths, node_id) => {
(self.visit_callback)(node_id);
for path in paths.iter() {
(self.visit_callback)(path.node.id)
}
}
}
}
}
}
visit::visit_view_item(self as @Visitor<()>, view_item, env)
}
fn visit_foreign_item(@mut self, foreign_item: @foreign_item, env: ()) {
(self.visit_callback)(foreign_item.id);
visit::visit_foreign_item(self as @Visitor<()>, foreign_item, env)
}
fn visit_item(@mut self, item: @item, env: ()) {
if !self.pass_through_items {
if self.visited_outermost {
return
} else {
self.visited_outermost = true
}
}
(self.visit_callback)(item.id);
match item.node {
item_enum(ref enum_definition, _) => {
for variant in enum_definition.variants.iter() {
(self.visit_callback)(variant.node.id)
}
}
_ => {}
}
visit::visit_item(self as @Visitor<()>, item, env);
self.visited_outermost = false
}
fn visit_local(@mut self, local: @Local, env: ()) {
(self.visit_callback)(local.id);
visit::visit_local(self as @Visitor<()>, local, env)
}
fn visit_block(@mut self, block: &Block, env: ()) {
(self.visit_callback)(block.id);
visit::visit_block(self as @Visitor<()>, block, env)
}
fn visit_stmt(@mut self, statement: @stmt, env: ()) {
(self.visit_callback)(ast_util::stmt_id(statement));
visit::visit_stmt(self as @Visitor<()>, statement, env)
}
// XXX: Default
fn visit_arm(@mut self, arm: &arm, env: ()) {
visit::visit_arm(self as @Visitor<()>, arm, env)
}
fn visit_pat(@mut self, pattern: @pat, env: ()) {
(self.visit_callback)(pattern.id);
visit::visit_pat(self as @Visitor<()>, pattern, env)
}
// XXX: Default
fn visit_decl(@mut self, declaration: @decl, env: ()) {
visit::visit_decl(self as @Visitor<()>, declaration, env)
}
fn visit_expr(@mut self, expression: @expr, env: ()) {
{
let optional_callee_id = expression.get_callee_id();
for callee_id in optional_callee_id.iter() {
(self.visit_callback)(*callee_id)
}
}
(self.visit_callback)(expression.id);
visit::visit_expr(self as @Visitor<()>, expression, env)
}
// XXX: Default
fn visit_expr_post(@mut self, _: @expr, _: ()) {
// Empty!
}
fn visit_ty(@mut self, typ: &Ty, env: ()) {
(self.visit_callback)(typ.id);
match typ.node {
ty_path(_, _, id) => (self.visit_callback)(id),
_ => {}
}
visit::visit_ty(self as @Visitor<()>, typ, env)
}
fn visit_generics(@mut self, generics: &Generics, env: ()) {
self.visit_generics_helper(generics);
visit::visit_generics(self as @Visitor<()>, generics, env)
}
fn visit_fn(@mut self,
function_kind: &visit::fn_kind,
function_declaration: &fn_decl,
block: &Block,
span: span,
node_id: NodeId,
env: ()) {
if !self.pass_through_items {
match *function_kind {
visit::fk_method(*) if self.visited_outermost => return,
visit::fk_method(*) => self.visited_outermost = true,
_ => {}
}
}
(self.visit_callback)(node_id);
match *function_kind {
visit::fk_item_fn(_, generics, _, _) => {
self.visit_generics_helper(generics)
}
visit::fk_method(_, generics, method) => {
(self.visit_callback)(method.self_id);
self.visit_generics_helper(generics)
}
visit::fk_anon(_) | visit::fk_fn_block => {}
}
for argument in function_declaration.inputs.iter() {
(self.visit_callback)(argument.id)
}
visit::visit_fn(self as @Visitor<()>,
function_kind,
function_declaration,
block,
span,
node_id,
env);
if !self.pass_through_items {
match *function_kind {
visit::fk_method(*) => self.visited_outermost = false,
_ => {}
}
}
}
// XXX: Default
fn visit_ty_method(@mut self, type_method: &TypeMethod, env: ()) {
visit::visit_ty_method(self as @Visitor<()>, type_method, env)
}
// XXX: Default
fn visit_trait_method(@mut self, trait_method: &trait_method, env: ()) {
visit::visit_trait_method(self as @Visitor<()>, trait_method, env)
}
// XXX: Default
fn visit_struct_def(@mut self,
struct_definition: @struct_def,
identifier: ident,
generics: &Generics,
node_id: NodeId,
env: ()) {
visit::visit_struct_def(self as @Visitor<()>,
struct_definition,
identifier,
generics,
node_id,
env)
}
fn visit_struct_field(@mut self, struct_field: @struct_field, env: ()) {
(self.visit_callback)(struct_field.node.id);
visit::visit_struct_field(self as @Visitor<()>, struct_field, env)
}
}
pub fn id_visitor(vfn: @fn(NodeId), pass_through_items: bool)
-> @Visitor<()> {
let visitor = @IdVisitor {
visit_callback: vfn,
pass_through_items: pass_through_items,
visited_outermost: false,
};
visitor as @Visitor<()>
}
pub fn visit_ids_for_inlined_item(item: &inlined_item, vfn: @fn(NodeId)) {
item.accept((), id_visitor(|id| vfn(id), true));
}
pub fn compute_id_range(visit_ids_fn: &fn(@fn(NodeId))) -> id_range {
let result = @mut id_range::max();
do visit_ids_fn |id| {
result.add(id);
}
*result
}
pub fn compute_id_range_for_inlined_item(item: &inlined_item) -> id_range {
compute_id_range(|f| visit_ids_for_inlined_item(item, f))
}
pub fn is_item_impl(item: @ast::item) -> bool {
match item.node {
item_impl(*) => true,
_ => false
}
}
pub fn walk_pat(pat: @pat, it: &fn(@pat) -> bool) -> bool {
if !it(pat) {
return false;
}
match pat.node {
pat_ident(_, _, Some(p)) => walk_pat(p, it),
pat_struct(_, ref fields, _) => {
fields.iter().advance(|f| walk_pat(f.pat, |p| it(p)))
}
pat_enum(_, Some(ref s)) | pat_tup(ref s) => {
s.iter().advance(|&p| walk_pat(p, |p| it(p)))
}
pat_box(s) | pat_uniq(s) | pat_region(s) => {
walk_pat(s, it)
}
pat_vec(ref before, ref slice, ref after) => {
before.iter().advance(|&p| walk_pat(p, |p| it(p))) &&
slice.iter().advance(|&p| walk_pat(p, |p| it(p))) &&
after.iter().advance(|&p| walk_pat(p, |p| it(p)))
}
pat_wild | pat_lit(_) | pat_range(_, _) | pat_ident(_, _, _) |
pat_enum(_, _) => {
true
}
}
}
pub trait EachViewItem {
pub fn each_view_item(&self, f: @fn(&ast::view_item) -> bool) -> bool;
}
struct EachViewItemData {
callback: @fn(&ast::view_item) -> bool,
}
impl SimpleVisitor for EachViewItemData {
fn visit_mod(@mut self, _: &_mod, _: span, _: NodeId) {
// XXX: Default method.
}
fn visit_view_item(@mut self, view_item: &view_item) {
let _ = (self.callback)(view_item);
}
fn visit_foreign_item(@mut self, _: @foreign_item) {
// XXX: Default method.
}
fn visit_item(@mut self, _: @item) {
// XXX: Default method.
}
fn visit_local(@mut self, _: @Local) {
// XXX: Default method.
}
fn visit_block(@mut self, _: &Block) {
// XXX: Default method.
}
fn visit_stmt(@mut self, _: @stmt) {
// XXX: Default method.
}
fn visit_arm(@mut self, _: &arm) {
// XXX: Default method.
}
fn visit_pat(@mut self, _: @pat) {
// XXX: Default method.
}
fn visit_decl(@mut self, _: @decl) {
// XXX: Default method.
}
fn visit_expr(@mut self, _: @expr) {
// XXX: Default method.
}
fn visit_expr_post(@mut self, _: @expr) {
// XXX: Default method.
}
fn visit_ty(@mut self, _: &Ty) {
// XXX: Default method.
}
fn visit_generics(@mut self, _: &Generics) {
// XXX: Default method.
}
fn visit_fn(@mut self,
_: &visit::fn_kind,
_: &fn_decl,
_: &Block,
_: span,
_: NodeId) {
// XXX: Default method.
}
fn visit_ty_method(@mut self, _: &TypeMethod) {
// XXX: Default method.
}
fn visit_trait_method(@mut self, _: &trait_method) {
// XXX: Default method.
}
fn visit_struct_def(@mut self,
_: @struct_def,
_: ident,
_: &Generics,
_: NodeId) {
// XXX: Default method.
}
fn visit_struct_field(@mut self, _: @struct_field) {
// XXX: Default method.
}
fn visit_struct_method(@mut self, _: @method) {
// XXX: Default method.
}
}
impl EachViewItem for ast::Crate {
fn each_view_item(&self, f: @fn(&ast::view_item) -> bool) -> bool {
let data = @mut EachViewItemData {
callback: f,
};
let visitor = @mut SimpleVisitorVisitor {
simple_visitor: data as @SimpleVisitor,
};
visit::visit_crate(visitor as @Visitor<()>, self, ());
true
}
}
pub fn view_path_id(p: &view_path) -> NodeId {
match p.node {
view_path_simple(_, _, id) |
view_path_glob(_, id) |
view_path_list(_, _, id) => id
}
}
/// Returns true if the given struct def is tuple-like; i.e. that its fields
/// are unnamed.
pub fn struct_def_is_tuple_like(struct_def: &ast::struct_def) -> bool {
struct_def.ctor_id.is_some()
}
pub fn visibility_to_privacy(visibility: visibility) -> Privacy {
match visibility {
public => Public,
inherited | private => Private
}
}
pub fn variant_visibility_to_privacy(visibility: visibility,
enclosing_is_public: bool)
-> Privacy {
if enclosing_is_public {
match visibility {
public | inherited => Public,
private => Private
}
} else {
visibility_to_privacy(visibility)
}
}
#[deriving(Eq)]
pub enum Privacy {
Private,
Public
}
/// Returns true if the given pattern consists solely of an identifier
/// and false otherwise.
pub fn pat_is_ident(pat: @ast::pat) -> bool {
match pat.node {
ast::pat_ident(*) => true,
_ => false,
}
}
// HYGIENE FUNCTIONS
/// Construct an identifier with the given name and an empty context:
pub fn new_ident(name: Name) -> ident { ident {name: name, ctxt: 0}}
/// Extend a syntax context with a given mark
pub fn new_mark(m:Mrk, tail:SyntaxContext) -> SyntaxContext {
new_mark_internal(m,tail,get_sctable())
}
// Extend a syntax context with a given mark and table
// FIXME #4536 : currently pub to allow testing
pub fn new_mark_internal(m:Mrk, tail:SyntaxContext,table:&mut SCTable)
-> SyntaxContext {
let key = (tail,m);
// FIXME #5074 : can't use more natural style because we're missing
// flow-sensitivity. Results in two lookups on a hash table hit.
// also applies to new_rename_internal, below.
// let try_lookup = table.mark_memo.find(&key);
match table.mark_memo.contains_key(&key) {
false => {
let new_idx = idx_push(&mut table.table,Mark(m,tail));
table.mark_memo.insert(key,new_idx);
new_idx
}
true => {
match table.mark_memo.find(&key) {
None => fail!(~"internal error: key disappeared 2013042901"),
Some(idxptr) => {*idxptr}
}
}
}
}
/// Extend a syntax context with a given rename
pub fn new_rename(id:ident, to:Name, tail:SyntaxContext) -> SyntaxContext {
new_rename_internal(id, to, tail, get_sctable())
}
// Extend a syntax context with a given rename and sctable
// FIXME #4536 : currently pub to allow testing
pub fn new_rename_internal(id:ident, to:Name, tail:SyntaxContext, table: &mut SCTable)
-> SyntaxContext {
let key = (tail,id,to);
// FIXME #5074
//let try_lookup = table.rename_memo.find(&key);
match table.rename_memo.contains_key(&key) {
false => {
let new_idx = idx_push(&mut table.table,Rename(id,to,tail));
table.rename_memo.insert(key,new_idx);
new_idx
}
true => {
match table.rename_memo.find(&key) {
None => fail!(~"internal error: key disappeared 2013042902"),
Some(idxptr) => {*idxptr}
}
}
}
}
/// Make a fresh syntax context table with EmptyCtxt in slot zero
/// and IllegalCtxt in slot one.
// FIXME #4536 : currently pub to allow testing
pub fn new_sctable_internal() -> SCTable {
SCTable {
table: ~[EmptyCtxt,IllegalCtxt],
mark_memo: HashMap::new(),
rename_memo: HashMap::new()
}
}
// fetch the SCTable from TLS, create one if it doesn't yet exist.
pub fn get_sctable() -> @mut SCTable {
static sctable_key: local_data::Key<@@mut SCTable> = &local_data::Key;
match local_data::get(sctable_key, |k| k.map(|&k| *k)) {
None => {
let new_table = @@mut new_sctable_internal();
local_data::set(sctable_key,new_table);
*new_table
},
Some(intr) => *intr
}
}
/// Add a value to the end of a vec, return its index
fn idx_push<T>(vec: &mut ~[T], val: T) -> uint {
vec.push(val);
vec.len() - 1
}
/// Resolve a syntax object to a name, per MTWT.
pub fn resolve(id : ident) -> Name {
resolve_internal(id, get_sctable())
}
// Resolve a syntax object to a name, per MTWT.
// FIXME #4536 : currently pub to allow testing
pub fn resolve_internal(id : ident, table : &mut SCTable) -> Name {
match table.table[id.ctxt] {
EmptyCtxt => id.name,
// ignore marks here:
Mark(_,subctxt) => resolve_internal(ident{name:id.name, ctxt: subctxt},table),
// do the rename if necessary:
Rename(ident{name,ctxt},toname,subctxt) => {
// this could be cached or computed eagerly:
let resolvedfrom = resolve_internal(ident{name:name,ctxt:ctxt},table);
let resolvedthis = resolve_internal(ident{name:id.name,ctxt:subctxt},table);
if ((resolvedthis == resolvedfrom)
&& (marksof(ctxt,resolvedthis,table)
== marksof(subctxt,resolvedthis,table))) {
toname
} else {
resolvedthis
}
}
IllegalCtxt() => fail!(~"expected resolvable context, got IllegalCtxt")
}
}
/// Compute the marks associated with a syntax context.
// it's not clear to me whether it's better to use a [] mutable
// vector or a cons-list for this.
pub fn marksof(ctxt: SyntaxContext, stopname: Name, table: &SCTable) -> ~[Mrk] {
let mut result = ~[];
let mut loopvar = ctxt;
loop {
match table.table[loopvar] {
EmptyCtxt => {return result;},
Mark(mark,tl) => {
xorPush(&mut result,mark);
loopvar = tl;
},
Rename(_,name,tl) => {
// see MTWT for details on the purpose of the stopname.
// short version: it prevents duplication of effort.
if (name == stopname) {
return result;
} else {
loopvar = tl;
}
}
IllegalCtxt => fail!(~"expected resolvable context, got IllegalCtxt")
}
}
}
/// Push a name... unless it matches the one on top, in which
/// case pop and discard (so two of the same marks cancel)
pub fn xorPush(marks: &mut ~[uint], mark: uint) {
if ((marks.len() > 0) && (getLast(marks) == mark)) {
marks.pop();
} else {
marks.push(mark);
}
}
// get the last element of a mutable array.
// FIXME #4903: , must be a separate procedure for now.
pub fn getLast(arr: &~[Mrk]) -> uint {
*arr.last()
}
#[cfg(test)]
mod test {
use ast::*;
use super::*;
use std::io;
#[test] fn xorpush_test () {
let mut s = ~[];
xorPush(&mut s,14);
assert_eq!(s.clone(),~[14]);
xorPush(&mut s,14);
assert_eq!(s.clone(),~[]);
xorPush(&mut s,14);
assert_eq!(s.clone(),~[14]);
xorPush(&mut s,15);
assert_eq!(s.clone(),~[14,15]);
xorPush (&mut s,16);
assert_eq!(s.clone(),~[14,15,16]);
xorPush (&mut s,16);
assert_eq!(s.clone(),~[14,15]);
xorPush (&mut s,15);
assert_eq!(s.clone(),~[14]);
}
// convert a list of uints to an @[ident]
// (ignores the interner completely)
fn uints_to_idents (uints: &~[uint]) -> @~[ident] {
@uints.map(|u| ident {name:*u, ctxt: empty_ctxt})
}
fn id (u : uint, s: SyntaxContext) -> ident {
ident{name:u, ctxt: s}
}
// because of the SCTable, I now need a tidy way of
// creating syntax objects. Sigh.
#[deriving(Clone, Eq)]
enum TestSC {
M(Mrk),
R(ident,Name)
}
// unfold a vector of TestSC values into a SCTable,
// returning the resulting index
fn unfold_test_sc(tscs : ~[TestSC], tail: SyntaxContext, table : &mut SCTable)
-> SyntaxContext {
tscs.rev_iter().fold(tail, |tail : SyntaxContext, tsc : &TestSC|
{match *tsc {
M(mrk) => new_mark_internal(mrk,tail,table),
R(ident,name) => new_rename_internal(ident,name,tail,table)}})
}
// gather a SyntaxContext back into a vector of TestSCs
fn refold_test_sc(mut sc: SyntaxContext, table : &SCTable) -> ~[TestSC] {
let mut result = ~[];
loop {
match table.table[sc] {
EmptyCtxt => {return result;},
Mark(mrk,tail) => {
result.push(M(mrk));
sc = tail;
loop;
},
Rename(id,name,tail) => {
result.push(R(id,name));
sc = tail;
loop;
}
IllegalCtxt => fail!("expected resolvable context, got IllegalCtxt")
}
}
}
#[test] fn test_unfold_refold(){
let mut t = new_sctable_internal();
let test_sc = ~[M(3),R(id(101,0),14),M(9)];
assert_eq!(unfold_test_sc(test_sc.clone(),empty_ctxt,&mut t),4);
assert_eq!(t.table[2],Mark(9,0));
assert_eq!(t.table[3],Rename(id(101,0),14,2));
assert_eq!(t.table[4],Mark(3,3));
assert_eq!(refold_test_sc(4,&t),test_sc);
}
// extend a syntax context with a sequence of marks given
// in a vector. v[0] will be the outermost mark.
fn unfold_marks(mrks:~[Mrk],tail:SyntaxContext,table: &mut SCTable) -> SyntaxContext {
mrks.rev_iter().fold(tail, |tail:SyntaxContext, mrk:&Mrk|
{new_mark_internal(*mrk,tail,table)})
}
#[test] fn unfold_marks_test() {
let mut t = new_sctable_internal();
assert_eq!(unfold_marks(~[3,7],empty_ctxt,&mut t),3);
assert_eq!(t.table[2],Mark(7,0));
assert_eq!(t.table[3],Mark(3,2));
}
#[test] fn test_marksof () {
let stopname = 242;
let name1 = 243;
let mut t = new_sctable_internal();
assert_eq!(marksof (empty_ctxt,stopname,&t),~[]);
// FIXME #5074: ANF'd to dodge nested calls
{ let ans = unfold_marks(~[4,98],empty_ctxt,&mut t);
assert_eq! (marksof (ans,stopname,&t),~[4,98]);}
// does xoring work?
{ let ans = unfold_marks(~[5,5,16],empty_ctxt,&mut t);
assert_eq! (marksof (ans,stopname,&t), ~[16]);}
// does nested xoring work?
{ let ans = unfold_marks(~[5,10,10,5,16],empty_ctxt,&mut t);
assert_eq! (marksof (ans, stopname,&t), ~[16]);}
// rename where stop doesn't match:
{ let chain = ~[M(9),
R(id(name1,
new_mark_internal (4, empty_ctxt,&mut t)),
100101102),
M(14)];
let ans = unfold_test_sc(chain,empty_ctxt,&mut t);
assert_eq! (marksof (ans, stopname, &t), ~[9,14]);}
// rename where stop does match
{ let name1sc = new_mark_internal(4, empty_ctxt, &mut t);
let chain = ~[M(9),
R(id(name1, name1sc),
stopname),
M(14)];
let ans = unfold_test_sc(chain,empty_ctxt,&mut t);
assert_eq! (marksof (ans, stopname, &t), ~[9]); }
}
#[test] fn resolve_tests () {
let a = 40;
let mut t = new_sctable_internal();
// - ctxt is MT
assert_eq!(resolve_internal(id(a,empty_ctxt),&mut t),a);
// - simple ignored marks
{ let sc = unfold_marks(~[1,2,3],empty_ctxt,&mut t);
assert_eq!(resolve_internal(id(a,sc),&mut t),a);}
// - orthogonal rename where names don't match
{ let sc = unfold_test_sc(~[R(id(50,empty_ctxt),51),M(12)],empty_ctxt,&mut t);
assert_eq!(resolve_internal(id(a,sc),&mut t),a);}
// - rename where names do match, but marks don't
{ let sc1 = new_mark_internal(1,empty_ctxt,&mut t);
let sc = unfold_test_sc(~[R(id(a,sc1),50),
M(1),
M(2)],
empty_ctxt,&mut t);
assert_eq!(resolve_internal(id(a,sc),&mut t), a);}
// - rename where names and marks match
{ let sc1 = unfold_test_sc(~[M(1),M(2)],empty_ctxt,&mut t);
let sc = unfold_test_sc(~[R(id(a,sc1),50),M(1),M(2)],empty_ctxt,&mut t);
assert_eq!(resolve_internal(id(a,sc),&mut t), 50); }
// - rename where names and marks match by literal sharing
{ let sc1 = unfold_test_sc(~[M(1),M(2)],empty_ctxt,&mut t);
let sc = unfold_test_sc(~[R(id(a,sc1),50)],sc1,&mut t);
assert_eq!(resolve_internal(id(a,sc),&mut t), 50); }
// - two renames of the same var.. can only happen if you use
// local-expand to prevent the inner binding from being renamed
// during the rename-pass caused by the first:
io::println("about to run bad test");
{ let sc = unfold_test_sc(~[R(id(a,empty_ctxt),50),
R(id(a,empty_ctxt),51)],
empty_ctxt,&mut t);
assert_eq!(resolve_internal(id(a,sc),&mut t), 51); }
// the simplest double-rename:
{ let a_to_a50 = new_rename_internal(id(a,empty_ctxt),50,empty_ctxt,&mut t);
let a50_to_a51 = new_rename_internal(id(a,a_to_a50),51,a_to_a50,&mut t);
assert_eq!(resolve_internal(id(a,a50_to_a51),&mut t),51);
// mark on the outside doesn't stop rename:
let sc = new_mark_internal(9,a50_to_a51,&mut t);
assert_eq!(resolve_internal(id(a,sc),&mut t),51);
// but mark on the inside does:
let a50_to_a51_b = unfold_test_sc(~[R(id(a,a_to_a50),51),
M(9)],
a_to_a50,
&mut t);
assert_eq!(resolve_internal(id(a,a50_to_a51_b),&mut t),50);}
}
#[test] fn hashing_tests () {
let mut t = new_sctable_internal();
assert_eq!(new_mark_internal(12,empty_ctxt,&mut t),2);
assert_eq!(new_mark_internal(13,empty_ctxt,&mut t),3);
// using the same one again should result in the same index:
assert_eq!(new_mark_internal(12,empty_ctxt,&mut t),2);
// I'm assuming that the rename table will behave the same....
}
}