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Drop high-order combinators

This commit is contained in:
Aleksey Kladov 2018-01-20 17:21:13 +03:00
parent 3c612bfa3a
commit 410f948c5f
4 changed files with 136 additions and 137 deletions
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179
src/parser/event_parser/grammar/items.rs
View File

@ -2,93 +2,90 @@ use super::*;
pub(super) fn mod_contents(p: &mut Parser) {
attributes::inner_attributes(p);
repeat(p, |p| {
skip_to_first(
p, item_first, mod_contents_item,
"expected item",
)
});
}
fn item_first(p: &Parser) -> bool {
match p.current() {
STRUCT_KW | FN_KW | EXTERN_KW | MOD_KW | USE_KW | POUND | PUB_KW => true,
_ => false,
while !p.at(EOF) {
item(p);
}
}
fn mod_contents_item(p: &mut Parser) {
if item(p) {
if p.current() == SEMI {
node(p, ERROR, |p| {
p.error()
.message("expected item, found `;`\n\
consider removing this semicolon")
.emit();
p.bump();
})
}
}
}
fn item(p: &mut Parser) -> bool {
fn item(p: &mut Parser){
let attrs_start = p.mark();
attributes::outer_attributes(p);
visibility(p);
// node_if(p, USE_KW, USE_ITEM, use_item)
// || extern crate_fn
// || node_if(p, STATIC_KW, STATIC_ITEM, static_item)
// || node_if(p, CONST_KW, CONST_ITEM, const_item) or const FN!
// || unsafe trait, impl
// || node_if(p, FN_KW, FN_ITEM, fn_item)
// || node_if(p, TYPE_KW, TYPE_ITEM, type_item)
let la = p.raw_lookahead(1);
let item_start = p.mark();
let item_parsed = node_if(p, [EXTERN_KW, CRATE_KW], EXTERN_CRATE_ITEM, extern_crate_item)
|| node_if(p, MOD_KW, MOD_ITEM, mod_item)
|| node_if(p, USE_KW, USE_ITEM, use_item)
|| node_if(p, STRUCT_KW, STRUCT_ITEM, struct_item)
|| node_if(p, FN_KW, FN_ITEM, fn_item);
match p.current() {
EXTERN_KW if la == CRATE_KW => extern_crate_item(p),
MOD_KW => mod_item(p),
USE_KW => use_item(p),
STRUCT_KW => struct_item(p),
FN_KW => fn_item(p),
err_token => {
p.start(ERROR);
let message = if err_token == SEMI {
//TODO: if the item is incomplete, this messsage is misleading
"expected item, found `;`\n\
consider removing this semicolon"
} else {
"expected item"
};
p.error()
.message(message)
.emit();
p.bump();
p.finish();
return;
}
};
p.forward_parent(attrs_start, item_start);
item_parsed
}
fn struct_item(p: &mut Parser) {
if !p.expect(IDENT) {
return
}
generic_parameters(p);
match p.current() {
WHERE_KW => {
where_clause(p);
match p.current() {
SEMI => {
p.bump();
return
}
L_CURLY => named_fields(p),
_ => { //TODO: special case `(` error message
p.error()
.message("expected `;` or `{`")
.emit();
return
p.start(STRUCT_ITEM);
assert!(p.at(STRUCT_KW));
p.bump();
struct_inner(p);
p.finish();
fn struct_inner(p: &mut Parser) {
if !p.expect(IDENT) {
p.finish();
return
}
generic_parameters(p);
match p.current() {
WHERE_KW => {
where_clause(p);
match p.current() {
SEMI => {
p.bump();
return
}
L_CURLY => named_fields(p),
_ => { //TODO: special case `(` error message
p.error()
.message("expected `;` or `{`")
.emit();
return
}
}
}
}
SEMI => {
p.bump();
return
}
L_CURLY => named_fields(p),
L_PAREN => {
tuple_fields(p);
p.expect(SEMI);
},
_ => {
p.error()
.message("expected `;`, `{`, or `(`")
.emit();
return
SEMI => {
p.bump();
return
}
L_CURLY => named_fields(p),
L_PAREN => {
tuple_fields(p);
p.expect(SEMI);
},
_ => {
p.error()
.message("expected `;`, `{`, or `(`")
.emit();
return
}
}
}
}
@ -135,17 +132,28 @@ fn where_clause(_: &mut Parser) {
}
fn extern_crate_item(p: &mut Parser) {
p.start(EXTERN_CRATE_ITEM);
assert!(p.at(EXTERN_KW));
p.bump();
assert!(p.at(CRATE_KW));
p.bump();
p.expect(IDENT) && alias(p) && p.expect(SEMI);
p.finish();
}
fn mod_item(p: &mut Parser) {
if !p.expect(IDENT) {
return;
p.start(MOD_ITEM);
assert!(p.at(MOD_KW));
p.bump();
if p.expect(IDENT) && !p.eat(SEMI) {
p.curly_block(mod_contents);
}
if p.eat(SEMI) {
return;
}
p.curly_block(mod_contents);
p.finish()
}
pub(super) fn is_use_tree_start(kind: SyntaxKind) -> bool {
@ -153,8 +161,13 @@ pub(super) fn is_use_tree_start(kind: SyntaxKind) -> bool {
}
fn use_item(p: &mut Parser) {
p.start(USE_ITEM);
assert!(p.at(USE_KW));
p.bump();
use_tree(p);
p.expect(SEMI);
p.finish();
fn use_tree(p: &mut Parser) -> bool{
if node_if(p, STAR, USE_TREE, |_| ()) {
@ -210,8 +223,14 @@ fn use_item(p: &mut Parser) {
fn fn_item(p: &mut Parser) {
p.start(FN_ITEM);
assert!(p.at(FN_KW));
p.bump();
p.expect(IDENT) && p.expect(L_PAREN) && p.expect(R_PAREN)
&& p.curly_block(|_| ());
p.finish();
}

85
src/parser/event_parser/grammar/mod.rs
View File

@ -10,37 +10,39 @@ mod types;
mod paths;
pub(crate) fn file(p: &mut Parser) {
node(p, FILE, |p| {
p.eat(SHEBANG);
items::mod_contents(p);
})
p.start(FILE);
p.eat(SHEBANG);
items::mod_contents(p);
p.finish()
}
fn visibility(p: &mut Parser) {
node_if(p, PUB_KW, VISIBILITY, |p| {
if p.current() != L_PAREN {
return
}
match p.raw_lookahead(1) {
CRATE_KW | SELF_KW | SUPER_KW => {
p.bump();
p.bump();
if p.at(PUB_KW) {
p.start(VISIBILITY);
p.bump();
if p.at(L_PAREN) {
match p.raw_lookahead(1) {
CRATE_KW | SELF_KW | SUPER_KW | IN_KW => {
p.bump();
if p.bump() == IN_KW {
paths::use_path(p);
}
p.expect(R_PAREN);
}
_ => ()
}
IN_KW => {
p.bump();
p.bump();
paths::use_path(p);
}
_ => return
}
p.expect(R_PAREN);
});
p.finish();
}
}
fn alias(p: &mut Parser) -> bool {
node_if(p, AS_KW, ALIAS, |p| {
if p.at(AS_KW) {
p.start(ALIAS);
p.bump();
p.expect(IDENT);
});
p.finish();
}
true //FIXME: return false if three are errors
}
@ -92,40 +94,13 @@ fn comma_list<F: Fn(&mut Parser) -> bool>(p: &mut Parser, end: SyntaxKind, f: F)
}
fn skip_to_first<C, F>(p: &mut Parser, cond: C, f: F, message: &str) -> bool
where
C: Fn(&Parser) -> bool,
F: FnOnce(&mut Parser),
{
let mut skipped = false;
loop {
if cond(p) {
if skipped {
p.finish();
}
f(p);
return true;
}
if p.current() == EOF {
if skipped {
p.finish();
}
return false;
}
if !skipped {
p.start(ERROR);
p.error()
.message(message)
.emit();
}
p.bump();
skipped = true;
}
}
impl<'p> Parser<'p> {
fn at(&self, kind: SyntaxKind) -> bool {
self.current() == kind
}
pub(crate) fn expect(&mut self, kind: SyntaxKind) -> bool {
if self.current() == kind {
if self.at(kind) {
self.bump();
true
} else {
@ -195,4 +170,4 @@ impl<'a> Lookahead for AnyOf<'a> {
p.bump();
}
}
}

4
tests/data/parser/err/0001_item_recovery_in_file.txt
View File

@ -1,8 +1,10 @@
FILE@[0; 21)
ERROR@[0; 10)
ERROR@[0; 3)
err: `expected item`
IDENT@[0; 2)
WHITESPACE@[2; 3)
ERROR@[3; 10)
err: `expected item`
IDENT@[3; 8)
WHITESPACE@[8; 10)
STRUCT_ITEM@[10; 21)

5
tests/data/parser/err/0004_use_path_bad_segment.txt
View File

@ -11,7 +11,10 @@ FILE@[0; 12)
PATH_SEGMENT@[9; 9)
err: `expected identifier`
err: `expected SEMI`
ERROR@[9; 12)
ERROR@[9; 11)
err: `expected item`
INT_NUMBER@[9; 11)
ERROR@[11; 12)
err: `expected item, found `;`
consider removing this semicolon`
SEMI@[11; 12)