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Move to using % as an escape in format! #9161

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70 changes: 36 additions & 34 deletions src/libstd/fmt/parse.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -158,12 +158,10 @@ impl<'self> Iterator<Piece<'self>> for Parser<'self> {
Some((_, '{')) => {
self.cur.next();
let ret = Some(Argument(self.argument()));
if !self.consume('}') {
self.err(~"unterminated format string");
}
self.must_consume('}');
ret
}
Some((pos, '\\')) => {
Some((pos, '%')) => {
self.cur.next();
self.escape(); // ensure it's a valid escape sequence
Some(String(self.string(pos + 1))) // skip the '\' character
Expand Down Expand Up @@ -211,11 +209,29 @@ impl<'self> Parser<'self> {
}
}

/// Forcibly consume the specified character, or else emit an error
fn must_consume(&mut self, expected: char) {
match self.cur.clone().next() {
Some((_, maybe)) if expected == maybe => { self.cur.next(); }
Some((_, found)) => {
self.err(fmt!("expected '%c' but found '%c'", expected, found));
}
None => {
self.err(fmt!("expected '%c' but string was terminated", expected))
}
}
}

/// Attempts to consume any amount of whitespace followed by a character
fn wsconsume(&mut self, c: char) -> bool {
self.ws(); self.consume(c)
}

/// Similar to `wsconsume`, but invokes must_consume instead of consume
fn ws_must_consume(&mut self, c: char) {
self.ws(); self.must_consume(c)
}

/// Consumes all whitespace characters until the first non-whitespace
/// character
fn ws(&mut self) {
Expand All @@ -232,7 +248,7 @@ impl<'self> Parser<'self> {
fn escape(&mut self) -> char {
match self.cur.next() {
Some((_, c @ '#')) | Some((_, c @ '{')) |
Some((_, c @ '\\')) | Some((_, c @ '}')) => { c }
Some((_, c @ '%')) | Some((_, c @ '}')) => { c }
Some((_, c)) => {
self.err(fmt!("invalid escape character `%c`", c));
c
Expand All @@ -251,7 +267,7 @@ impl<'self> Parser<'self> {
loop {
// we may not consume the character, so clone the iterator
match self.cur.clone().next() {
Some((pos, '\\')) | Some((pos, '#')) |
Some((pos, '%')) | Some((pos, '#')) |
Some((pos, '}')) | Some((pos, '{')) => {
return self.input.slice(start, pos);
}
Expand Down Expand Up @@ -362,15 +378,11 @@ impl<'self> Parser<'self> {
self.ws();
match self.word() {
"select" => {
if !self.wsconsume(',') {
self.err(~"`select` must be followed by `,`");
}
self.ws_must_consume(',');
Some(self.select())
}
"plural" => {
if !self.wsconsume(',') {
self.err(~"`plural` must be followed by `,`");
}
self.ws_must_consume(',');
Some(self.plural())
}
"" => {
Expand All @@ -396,15 +408,11 @@ impl<'self> Parser<'self> {
self.err(~"cannot have an empty selector");
break
}
if !self.wsconsume('{') {
self.err(~"selector must be followed by `{`");
}
self.ws_must_consume('{');
self.depth += 1;
let pieces = self.collect();
self.depth -= 1;
if !self.wsconsume('}') {
self.err(~"selector case must be terminated by `}`");
}
self.ws_must_consume('}');
if selector == "other" {
if !other.is_none() {
self.err(~"multiple `other` statements in `select");
Expand Down Expand Up @@ -451,9 +459,7 @@ impl<'self> Parser<'self> {
self.err(fmt!("expected `offset`, found `%s`",
word));
} else {
if !self.consume(':') {
self.err(~"`offset` must be followed by `:`");
}
self.must_consume(':');
match self.integer() {
Some(i) => { offset = Some(i); }
None => {
Expand Down Expand Up @@ -499,15 +505,11 @@ impl<'self> Parser<'self> {
}
}
};
if !self.wsconsume('{') {
self.err(~"selector must be followed by `{`");
}
self.ws_must_consume('{');
self.depth += 1;
let pieces = self.collect();
self.depth -= 1;
if !self.wsconsume('}') {
self.err(~"selector case must be terminated by `}`");
}
self.ws_must_consume('}');
if isother {
if !other.is_none() {
self.err(~"multiple `other` statements in `select");
Expand Down Expand Up @@ -629,16 +631,16 @@ mod tests {
#[test]
fn simple() {
same("asdf", ~[String("asdf")]);
same("a\\{b", ~[String("a"), String("{b")]);
same("a\\#b", ~[String("a"), String("#b")]);
same("a\\}b", ~[String("a"), String("}b")]);
same("a\\}", ~[String("a"), String("}")]);
same("\\}", ~[String("}")]);
same("a%{b", ~[String("a"), String("{b")]);
same("a%#b", ~[String("a"), String("#b")]);
same("a%}b", ~[String("a"), String("}b")]);
same("a%}", ~[String("a"), String("}")]);
same("%}", ~[String("}")]);
}

#[test] #[should_fail] fn invalid01() { musterr("{") }
#[test] #[should_fail] fn invalid02() { musterr("\\") }
#[test] #[should_fail] fn invalid03() { musterr("\\a") }
#[test] #[should_fail] fn invalid02() { musterr("%") }
#[test] #[should_fail] fn invalid03() { musterr("%a") }
#[test] #[should_fail] fn invalid04() { musterr("{3a}") }
#[test] #[should_fail] fn invalid05() { musterr("{:|}") }
#[test] #[should_fail] fn invalid06() { musterr("{:>>>}") }
Expand Down
14 changes: 7 additions & 7 deletions src/test/compile-fail/ifmt-bad-arg.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -39,20 +39,20 @@ fn main() {

// bad syntax of the format string

format!("{"); //~ ERROR: unterminated format string
format!("\\ "); //~ ERROR: invalid escape
format!("\\"); //~ ERROR: expected an escape
format!("{"); //~ ERROR: expected '}'
format!("% "); //~ ERROR: invalid escape
format!("%"); //~ ERROR: expected an escape

format!("{0, }", 1); //~ ERROR: expected method
format!("{0, foo}", 1); //~ ERROR: unknown method
format!("{0, select}", "a"); //~ ERROR: must be followed by
format!("{0, plural}", 1); //~ ERROR: must be followed by
format!("{0, select}", "a"); //~ ERROR: expected ',' but found '}'
format!("{0, plural}", 1); //~ ERROR: expected ',' but found '}'

format!("{0, select, a{{}", 1); //~ ERROR: must be terminated
format!("{0, select, a{{}", 1); //~ ERROR: expected '}' but
format!("{0, select, {} other{}}", "a"); //~ ERROR: empty selector
format!("{0, select, other{} other{}}", "a"); //~ ERROR: multiple `other`
format!("{0, plural, offset: other{}}", "a"); //~ ERROR: must be an integer
format!("{0, plural, offset 1 other{}}", "a"); //~ ERROR: be followed by `:`
format!("{0, plural, offset 1 other{}}", "a"); //~ ERROR: expected ':'
format!("{0, plural, =a{} other{}}", "a"); //~ ERROR: followed by an integer
format!("{0, plural, a{} other{}}", "a"); //~ ERROR: unexpected plural
format!("{0, select, a{}}", "a"); //~ ERROR: must provide an `other`
Expand Down
10 changes: 5 additions & 5 deletions src/test/run-pass/ifmt.rs
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Expand Up @@ -43,7 +43,7 @@ pub fn main() {
// Various edge cases without formats
t!(format!(""), "");
t!(format!("hello"), "hello");
t!(format!("hello \\{"), "hello {");
t!(format!("hello %{"), "hello {");

// default formatters should work
t!(format!("{}", 1i), "1");
Expand Down Expand Up @@ -222,10 +222,10 @@ pub fn main() {
t!(format!("{:+10.3f}", -1.0f), " -1.000");

// Escaping
t!(format!("\\{"), "{");
t!(format!("\\}"), "}");
t!(format!("\\#"), "#");
t!(format!("\\\\"), "\\");
t!(format!("%{"), "{");
t!(format!("%}"), "}");
t!(format!("%#"), "#");
t!(format!("%%"), "%");

test_write();
test_print();
Expand Down