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Cleanup libsyntax a bit #7873

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200 changes: 100 additions & 100 deletions src/libsyntax/parse/parser.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -406,7 +406,9 @@ impl Parser {
// consume token 'tok' if it exists. Returns true if the given
// token was present, false otherwise.
pub fn eat(&self, tok: &token::Token) -> bool {
return if *self.token == *tok { self.bump(); true } else { false };
let is_present = *self.token == *tok;
if is_present { self.bump() }
is_present
}

pub fn is_keyword(&self, kw: keywords::Keyword) -> bool {
Expand Down Expand Up @@ -458,21 +460,16 @@ impl Parser {
// with a single > and continue. If a GT is not seen,
// signal an error.
pub fn expect_gt(&self) {
if *self.token == token::GT {
self.bump();
} else if *self.token == token::BINOP(token::SHR) {
self.replace_token(
match *self.token {
token::GT => self.bump(),
token::BINOP(token::SHR) => self.replace_token(
token::GT,
self.span.lo + BytePos(1u),
self.span.hi
);
} else {
let mut s: ~str = ~"expected `";
s.push_str(self.token_to_str(&token::GT));
s.push_str("`, found `");
s.push_str(self.this_token_to_str());
s.push_str("`");
self.fatal(s);
),
_ => self.fatal(fmt!("expected `%s`, found `%s`",
self.token_to_str(&token::GT),
self.this_token_to_str()))
}
}

Expand Down Expand Up @@ -1114,19 +1111,20 @@ impl Parser {
}

pub fn is_named_argument(&self) -> bool {
let offset = if *self.token == token::BINOP(token::AND) {
1
} else if *self.token == token::BINOP(token::MINUS) {
1
} else if *self.token == token::ANDAND {
1
} else if *self.token == token::BINOP(token::PLUS) {
if self.look_ahead(1, |t| *t == token::BINOP(token::PLUS)) {
2
} else {
1
}
} else { 0 };
let offset = match *self.token {
token::BINOP(token::AND) => 1,
token::BINOP(token::MINUS) => 1,
token::ANDAND => 1,
token::BINOP(token::PLUS) => {
if self.look_ahead(1, |t| *t == token::BINOP(token::PLUS)) {
2
} else {
1
}
},
_ => 0
};

if offset == 0 {
is_plain_ident(&*self.token)
&& self.look_ahead(1, |t| *t == token::COLON)
Expand Down Expand Up @@ -1868,21 +1866,26 @@ impl Parser {
// parse an optional separator followed by a kleene-style
// repetition token (+ or *).
pub fn parse_sep_and_zerok(&self) -> (Option<token::Token>, bool) {
if *self.token == token::BINOP(token::STAR)
|| *self.token == token::BINOP(token::PLUS) {
let zerok = *self.token == token::BINOP(token::STAR);
self.bump();
(None, zerok)
} else {
let sep = self.bump_and_get();
if *self.token == token::BINOP(token::STAR)
|| *self.token == token::BINOP(token::PLUS) {
let zerok = *self.token == token::BINOP(token::STAR);
self.bump();
(Some(sep), zerok)
} else {
self.fatal("expected `*` or `+`");
fn parse_zerok(parser: &Parser) -> Option<bool> {
match *parser.token {
token::BINOP(token::STAR) | token::BINOP(token::PLUS) => {
let zerok = *parser.token == token::BINOP(token::STAR);
parser.bump();
Some(zerok)
},
_ => None
}
};

match parse_zerok(self) {
Some(zerok) => return (None, zerok),
None => {}
}

let separator = self.bump_and_get();
match parse_zerok(self) {
Some(zerok) => (Some(separator), zerok),
None => self.fatal("expected `*` or `+`")
}
}

Expand Down Expand Up @@ -2144,39 +2147,45 @@ impl Parser {
// parse an expression of binops of at least min_prec precedence
pub fn parse_more_binops(&self, lhs: @expr, min_prec: uint) -> @expr {
if self.expr_is_complete(lhs) { return lhs; }
if token::BINOP(token::OR) == *self.token &&
(*self.restriction == RESTRICT_NO_BAR_OP ||
*self.restriction == RESTRICT_NO_BAR_OR_DOUBLEBAR_OP) {
lhs
} else if token::OROR == *self.token &&
*self.restriction == RESTRICT_NO_BAR_OR_DOUBLEBAR_OP {
lhs
} else {
let cur_opt = token_to_binop(self.token);
match cur_opt {
Some(cur_op) => {
let cur_prec = operator_prec(cur_op);
if cur_prec > min_prec {
self.bump();
let expr = self.parse_prefix_expr();
let rhs = self.parse_more_binops(expr, cur_prec);
let bin = self.mk_expr(lhs.span.lo, rhs.span.hi,
self.mk_binary(cur_op, lhs, rhs));
self.parse_more_binops(bin, min_prec)
} else {
lhs
}

// Prevent dynamic borrow errors later on by limiting the
// scope of the borrows.
{
let token: &token::Token = self.token;
let restriction: &restriction = self.restriction;
match (token, restriction) {
(&token::BINOP(token::OR), &RESTRICT_NO_BAR_OP) => return lhs,
(&token::BINOP(token::OR),
&RESTRICT_NO_BAR_OR_DOUBLEBAR_OP) => return lhs,
(&token::OROR, &RESTRICT_NO_BAR_OR_DOUBLEBAR_OP) => return lhs,
_ => { }
}
}

let cur_opt = token_to_binop(self.token);
match cur_opt {
Some(cur_op) => {
let cur_prec = operator_prec(cur_op);
if cur_prec > min_prec {
self.bump();
let expr = self.parse_prefix_expr();
let rhs = self.parse_more_binops(expr, cur_prec);
let bin = self.mk_expr(lhs.span.lo, rhs.span.hi,
self.mk_binary(cur_op, lhs, rhs));
self.parse_more_binops(bin, min_prec)
} else {
lhs
}
None => {
if as_prec > min_prec && self.eat_keyword(keywords::As) {
let rhs = self.parse_ty(true);
let _as = self.mk_expr(lhs.span.lo,
rhs.span.hi,
expr_cast(lhs, rhs));
self.parse_more_binops(_as, min_prec)
} else {
lhs
}
}
None => {
if as_prec > min_prec && self.eat_keyword(keywords::As) {
let rhs = self.parse_ty(true);
let _as = self.mk_expr(lhs.span.lo,
rhs.span.hi,
expr_cast(lhs, rhs));
self.parse_more_binops(_as, min_prec)
} else {
lhs
}
}
}
Expand All @@ -2197,19 +2206,18 @@ impl Parser {
token::BINOPEQ(op) => {
self.bump();
let rhs = self.parse_expr();
let aop;
match op {
token::PLUS => aop = add,
token::MINUS => aop = subtract,
token::STAR => aop = mul,
token::SLASH => aop = div,
token::PERCENT => aop = rem,
token::CARET => aop = bitxor,
token::AND => aop = bitand,
token::OR => aop = bitor,
token::SHL => aop = shl,
token::SHR => aop = shr
}
let aop = match op {
token::PLUS => add,
token::MINUS => subtract,
token::STAR => mul,
token::SLASH => div,
token::PERCENT => rem,
token::CARET => bitxor,
token::AND => bitand,
token::OR => bitor,
token::SHL => shl,
token::SHR => shr
};
self.mk_expr(lo, rhs.span.hi,
self.mk_assign_op(aop, lhs, rhs))
}
Expand Down Expand Up @@ -2758,6 +2766,7 @@ impl Parser {
self.bump();
let (before, slice, after) =
self.parse_pat_vec_elements();

self.expect(&token::RBRACKET);
pat = ast::pat_vec(before, slice, after);
hi = self.last_span.hi;
Expand Down Expand Up @@ -3349,19 +3358,15 @@ impl Parser {
}

// parse a generic use site
fn parse_generic_values(
&self) -> (OptVec<ast::Lifetime>, ~[Ty])
{
fn parse_generic_values(&self) -> (OptVec<ast::Lifetime>, ~[Ty]) {
if !self.eat(&token::LT) {
(opt_vec::Empty, ~[])
} else {
self.parse_generic_values_after_lt()
}
}

fn parse_generic_values_after_lt(
&self) -> (OptVec<ast::Lifetime>, ~[Ty])
{
fn parse_generic_values_after_lt(&self) -> (OptVec<ast::Lifetime>, ~[Ty]) {
let lifetimes = self.parse_lifetimes();
let result = self.parse_seq_to_gt(
Some(token::COMMA),
Expand Down Expand Up @@ -3390,11 +3395,7 @@ impl Parser {
}

fn is_self_ident(&self) -> bool {
match *self.token {
token::IDENT(id, false) if id == special_idents::self_
=> true,
_ => false
}
*self.token == token::IDENT(special_idents::self_, false)
}

fn expect_self_ident(&self) {
Expand Down Expand Up @@ -4649,14 +4650,12 @@ impl Parser {

pub fn parse_item(&self, attrs: ~[Attribute]) -> Option<@ast::item> {
match self.parse_item_or_view_item(attrs, true) {
iovi_none(_) =>
None,
iovi_none(_) => None,
iovi_view_item(_) =>
self.fatal("view items are not allowed here"),
iovi_foreign_item(_) =>
self.fatal("foreign items are not allowed here"),
iovi_item(item) =>
Some(item)
iovi_item(item) => Some(item)
}
}

Expand Down Expand Up @@ -4819,6 +4818,7 @@ impl Parser {
// First, parse view items.
let mut view_items : ~[ast::view_item] = ~[];
let mut items = ~[];

// I think this code would probably read better as a single
// loop with a mutable three-state-variable (for extern mods,
// view items, and regular items) ... except that because
Expand Down