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Simplify rewrite_pair

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This commit is contained in:
topecongiro 2017-07-26 17:40:57 +09:00
parent e523f053a3
commit 2ffe4d0563
1 changed files with 24 additions and 63 deletions
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87
src/expr.rs
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@ -370,56 +370,37 @@ where
LHS: Rewrite,
RHS: Rewrite,
{
// Get "full width" rhs and see if it fits on the current line. This
// usually works fairly well since it tends to place operands of
// operations with high precendence close together.
// Note that this is non-conservative, but its just to see if it's even
// worth trying to put everything on one line.
let rhs_shape = try_opt!(shape.sub_width(suffix.len()));
let rhs_orig_result = rhs.rewrite(context, rhs_shape);
let sep = if infix.ends_with(' ') { " " } else { "" };
let infix = infix.trim_right();
let lhs_overhead = shape.used_width() + prefix.len() + infix.len();
let lhs_shape = Shape {
width: try_opt!(context.config.max_width().checked_sub(lhs_overhead)),
..shape
};
let lhs_result = try_opt!(
lhs.rewrite(context, lhs_shape)
.map(|lhs_str| format!("{}{}{}", prefix, lhs_str, infix))
);
// Try to the both lhs and rhs on the same line.
let rhs_orig_result = shape
.offset_left(last_line_width(&lhs_result) + suffix.len() + sep.len())
.and_then(|rhs_shape| rhs.rewrite(context, rhs_shape));
if let Some(ref rhs_result) = rhs_orig_result {
// This is needed in case of line break not caused by a
// shortage of space, but by end-of-line comments, for example.
if !rhs_result.contains('\n') {
let lhs_shape =
try_opt!(try_opt!(shape.offset_left(prefix.len())).sub_width(infix.len()));
let lhs_result = lhs.rewrite(context, lhs_shape);
if let Some(lhs_result) = lhs_result {
let mut result = format!("{}{}{}", prefix, lhs_result, infix);
let remaining_width = shape
.width
.checked_sub(last_line_width(&result) + suffix.len())
.unwrap_or(0);
if rhs_result.len() <= remaining_width {
result.push_str(&rhs_result);
result.push_str(suffix);
return Some(result);
}
// Try rewriting the rhs into the remaining space.
let rhs_shape = shape.offset_left(last_line_width(&result) + suffix.len());
if let Some(rhs_shape) = rhs_shape {
if let Some(rhs_result) = rhs.rewrite(context, rhs_shape) {
// FIXME this should always hold.
if rhs_result.len() <= remaining_width {
result.push_str(&rhs_result);
result.push_str(suffix);
return Some(result);
}
}
}
}
// If the rhs looks like block expression, we allow it to stay on the same line
// with the lhs even if it is multi-lined.
let allow_same_line = rhs_result
.lines()
.next()
.map(|first_line| first_line.ends_with('{'))
.unwrap_or(false);
if !rhs_result.contains('\n') || allow_same_line {
return Some(format!("{}{}{}{}", lhs_result, sep, rhs_result, suffix));
}
}
// We have to use multiple lines.
// Re-evaluate the rhs because we have more space now:
let sep = if infix.ends_with(' ') { " " } else { "" };
let infix = infix.trim_right();
let rhs_shape = match context.config.control_style() {
Style::Legacy => {
try_opt!(shape.sub_width(suffix.len() + prefix.len())).visual_indent(prefix.len())
@ -434,26 +415,6 @@ where
}
};
let rhs_result = try_opt!(rhs.rewrite(context, rhs_shape));
let lhs_overhead = shape.used_width() + prefix.len() + infix.len();
let lhs_shape = Shape {
width: try_opt!(context.config.max_width().checked_sub(lhs_overhead)),
..shape
};
let lhs_result = try_opt!(
lhs.rewrite(context, lhs_shape)
.map(|lhs_str| format!("{}{}{}", prefix, lhs_str, infix))
);
if let Some(ref rhs_str) = rhs_orig_result {
if rhs_str.lines().count() <= rhs_result.lines().count() &&
rhs_str
.lines()
.next()
.map_or(false, |first_line| first_line.ends_with('{')) &&
last_line_width(&lhs_result) + sep.len() + first_line_width(rhs_str) <= shape.width
{
return Some(format!("{}{}{}{}", lhs_result, sep, rhs_str, suffix));
}
}
Some(format!(
"{}\n{}{}{}",
lhs_result,