syntax: Rewrite pp advance_left to use a constant stack size

This commit is contained in:
Erick Tryzelaar 2015-01-13 21:14:56 -08:00
parent 92b48556e0
commit caf4a90c66

View file

@ -317,9 +317,7 @@ impl Printer {
Token::Eof => {
if !self.scan_stack_empty {
self.check_stack(0);
let left = self.token[self.left].clone();
let left_size = self.size[self.left];
try!(self.advance_left(left, left_size));
try!(self.advance_left());
}
self.indent(0);
Ok(())
@ -370,16 +368,16 @@ impl Printer {
self.right_total += b.blank_space;
Ok(())
}
Token::String(ref s, len) => {
Token::String(s, len) => {
if self.scan_stack_empty {
debug!("pp String('{}')/print ~[{},{}]",
*s, self.left, self.right);
self.print(token.clone(), len)
s, self.left, self.right);
self.print(Token::String(s, len), len)
} else {
debug!("pp String('{}')/buffer ~[{},{}]",
*s, self.left, self.right);
s, self.left, self.right);
self.advance_right();
self.token[self.right] = token.clone();
self.token[self.right] = Token::String(s, len);
self.size[self.right] = len;
self.right_total += len;
self.check_stream()
@ -400,9 +398,7 @@ impl Printer {
self.size[scanned] = SIZE_INFINITY;
}
}
let left = self.token[self.left].clone();
let left_size = self.size[self.left];
try!(self.advance_left(left, left_size));
try!(self.advance_left());
if self.left != self.right {
try!(self.check_stream());
}
@ -449,29 +445,39 @@ impl Printer {
self.right %= self.buf_len;
assert!((self.right != self.left));
}
pub fn advance_left(&mut self, x: Token, l: int) -> io::IoResult<()> {
pub fn advance_left(&mut self) -> io::IoResult<()> {
debug!("advance_left ~[{},{}], sizeof({})={}", self.left, self.right,
self.left, l);
if l >= 0 {
let ret = self.print(x.clone(), l);
match x {
Token::Break(b) => self.left_total += b.blank_space,
Token::String(_, len) => {
assert_eq!(len, l); self.left_total += len;
}
_ => ()
self.left, self.size[self.left]);
let mut left_size = self.size[self.left];
while left_size >= 0 {
let left = self.token[self.left].clone();
let len = match left {
Token::Break(b) => b.blank_space,
Token::String(_, len) => {
assert_eq!(len, left_size);
len
}
_ => 0
};
try!(self.print(left, left_size));
self.left_total += len;
if self.left == self.right {
break;
}
if self.left != self.right {
self.left += 1u;
self.left %= self.buf_len;
let left = self.token[self.left].clone();
let left_size = self.size[self.left];
try!(self.advance_left(left, left_size));
}
ret
} else {
Ok(())
self.left += 1u;
self.left %= self.buf_len;
left_size = self.size[self.left];
}
Ok(())
}
pub fn check_stack(&mut self, k: int) {
if !self.scan_stack_empty {