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libfmt_macros: resolve all implicit refs while parsing

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This commit is contained in:
Wang Xuerui 2016-05-16 14:10:54 +08:00
parent 4a12a70a5c
commit 71949f3b0d
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GPG key ID: 78396CEF692310EC
1 changed files with 46 additions and 11 deletions
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57
src/libfmt_macros/lib.rs
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@ -144,6 +144,8 @@ pub struct Parser<'a> {
cur: iter::Peekable<str::CharIndices<'a>>,
/// Error messages accumulated during parsing
pub errors: Vec<string::String>,
/// Current position of implicit positional argument pointer
curarg: usize,
}
impl<'a> Iterator for Parser<'a> {
@ -186,6 +188,7 @@ impl<'a> Parser<'a> {
input: s,
cur: s.char_indices().peekable(),
errors: vec![],
curarg: 0,
}
}
@ -259,9 +262,41 @@ impl<'a> Parser<'a> {
/// Parses an Argument structure, or what's contained within braces inside
/// the format string
fn argument(&mut self) -> Argument<'a> {
let mut pos = self.position();
let mut format = self.format();
// Resolve CountIsNextParam's into absolute references.
// Current argument's position must be known so this is done after
// format parsing.
// Curiously, currently {:.*} for named arguments is implemented,
// and it consumes a positional arg slot just like a positional {:.*}
// does. The current behavior is reproduced to prevent any
// incompatibilities.
match format.precision {
CountIsNextParam => {
// eat the current implicit arg
let i = self.curarg;
self.curarg += 1;
format.precision = CountIsParam(i);
}
_ => {}
}
// Resolve ArgumentNext's into absolute references.
// This must come after count resolution because we may consume one
// more arg if precision is CountIsNextParam.
match pos {
ArgumentNext => {
let i = self.curarg;
self.curarg += 1;
pos = ArgumentIs(i);
}
_ => {}
}
Argument {
position: self.position(),
format: self.format(),
position: pos,
format: format,
}
}
@ -487,7 +522,7 @@ mod tests {
fn format_nothing() {
same("{}",
&[NextArgument(Argument {
position: ArgumentNext,
position: ArgumentIs(0),
format: fmtdflt(),
})]);
}
@ -565,7 +600,7 @@ mod tests {
fn format_counts() {
same("{:10s}",
&[NextArgument(Argument {
position: ArgumentNext,
position: ArgumentIs(0),
format: FormatSpec {
fill: None,
align: AlignUnknown,
@ -577,7 +612,7 @@ mod tests {
})]);
same("{:10$.10s}",
&[NextArgument(Argument {
position: ArgumentNext,
position: ArgumentIs(0),
format: FormatSpec {
fill: None,
align: AlignUnknown,
@ -589,19 +624,19 @@ mod tests {
})]);
same("{:.*s}",
&[NextArgument(Argument {
position: ArgumentNext,
position: ArgumentIs(1),
format: FormatSpec {
fill: None,
align: AlignUnknown,
flags: 0,
precision: CountIsNextParam,
precision: CountIsParam(0),
width: CountImplied,
ty: "s",
},
})]);
same("{:.10$s}",
&[NextArgument(Argument {
position: ArgumentNext,
position: ArgumentIs(0),
format: FormatSpec {
fill: None,
align: AlignUnknown,
@ -613,7 +648,7 @@ mod tests {
})]);
same("{:a$.b$s}",
&[NextArgument(Argument {
position: ArgumentNext,
position: ArgumentIs(0),
format: FormatSpec {
fill: None,
align: AlignUnknown,
@ -628,7 +663,7 @@ mod tests {
fn format_flags() {
same("{:-}",
&[NextArgument(Argument {
position: ArgumentNext,
position: ArgumentIs(0),
format: FormatSpec {
fill: None,
align: AlignUnknown,
@ -640,7 +675,7 @@ mod tests {
})]);
same("{:+#}",
&[NextArgument(Argument {
position: ArgumentNext,
position: ArgumentIs(0),
format: FormatSpec {
fill: None,
align: AlignUnknown,