rewrite_result for GenericBounds, GenericParam, SegmentParam

Author: ding-young

src/types.rs

@@ -168,11 +168,15 @@ impl<'a> Spanned for SegmentParam<'a> {
 
 impl<'a> Rewrite for SegmentParam<'a> {
  fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
+ self.rewrite_result(context, shape).ok()
+ }
+
+ fn rewrite_result(&self, context: &RewriteContext<'_>, shape: Shape) -> RewriteResult {
  match *self {
- SegmentParam::Const(const_) => const_.rewrite(context, shape),
- SegmentParam::LifeTime(lt) => lt.rewrite(context, shape),
- SegmentParam::Type(ty) => ty.rewrite(context, shape),
- SegmentParam::Binding(atc) => atc.rewrite(context, shape),
+ SegmentParam::Const(const_) => const_.rewrite_result(context, shape),
+ SegmentParam::LifeTime(lt) => lt.rewrite_result(context, shape),
+ SegmentParam::Type(ty) => ty.rewrite_result(context, shape),
+ SegmentParam::Binding(atc) => atc.rewrite_result(context, shape),
  }
  }
 }
@@ -542,7 +546,7 @@ fn rewrite_bounded_lifetime(
  "{}{}{}",
  result,
  colon,
- join_bounds(context, shape.sub_width(overhead)?, bounds, true)?
+ join_bounds(context, shape.sub_width(overhead)?, bounds, true).ok()?
  );
  Some(result)
  }
@@ -605,8 +609,12 @@ impl Rewrite for ast::GenericBound {
 
 impl Rewrite for ast::GenericBounds {
  fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
+ self.rewrite_result(context, shape).ok()
+ }
+
+ fn rewrite_result(&self, context: &RewriteContext<'_>, shape: Shape) -> RewriteResult {
  if self.is_empty() {
- return Some(String::new());
+ return Ok(String::new());
  }
 
  join_bounds(context, shape, self, true)
@@ -615,8 +623,15 @@ impl Rewrite for ast::GenericBounds {
 
 impl Rewrite for ast::GenericParam {
  fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
+ self.rewrite_result(context, shape).ok()
+ }
+
+ fn rewrite_result(&self, context: &RewriteContext<'_>, shape: Shape) -> RewriteResult {
  // FIXME: If there are more than one attributes, this will force multiline.
- let mut result = self.attrs.rewrite(context, shape).unwrap_or(String::new());
+ let mut result = self
+ .attrs
+ .rewrite_result(context, shape)
+ .unwrap_or(String::new());
  let has_attrs = !result.is_empty();
 
  let mut param = String::with_capacity(128);
@@ -630,15 +645,19 @@ impl Rewrite for ast::GenericParam {
  param.push_str("const ");
  param.push_str(rewrite_ident(context, self.ident));
  param.push_str(": ");
- param.push_str(&ty.rewrite(context, shape)?);
+ param.push_str(&ty.rewrite_result(context, shape)?);
  if let Some(default) = default {
  let eq_str = match context.config.type_punctuation_density() {
  TypeDensity::Compressed => "=",
  TypeDensity::Wide => " = ",
  };
  param.push_str(eq_str);
- let budget = shape.width.checked_sub(param.len())?;
- let rewrite = default.rewrite(context, Shape::legacy(budget, shape.indent))?;
+ let budget = shape
+ .width
+ .checked_sub(param.len())
+ .max_width_error(shape.width, self.span())?;
+ let rewrite =
+ default.rewrite_result(context, Shape::legacy(budget, shape.indent))?;
  param.push_str(&rewrite);
  }
  kw_span.lo()
@@ -649,7 +668,7 @@ impl Rewrite for ast::GenericParam {
 
  if !self.bounds.is_empty() {
  param.push_str(type_bound_colon(context));
- param.push_str(&self.bounds.rewrite(context, shape)?)
+ param.push_str(&self.bounds.rewrite_result(context, shape)?)
  }
  if let ast::GenericParamKind::Type {
  default: Some(ref def),
@@ -660,9 +679,12 @@ impl Rewrite for ast::GenericParam {
  TypeDensity::Wide => " = ",
  };
  param.push_str(eq_str);
- let budget = shape.width.checked_sub(param.len())?;
+ let budget = shape
+ .width
+ .checked_sub(param.len())
+ .max_width_error(shape.width, self.span())?;
  let rewrite =
- def.rewrite(context, Shape::legacy(budget, shape.indent + param.len()))?;
+ def.rewrite_result(context, Shape::legacy(budget, shape.indent + param.len()))?;
  param.push_str(&rewrite);
  }
 
@@ -676,7 +698,8 @@ impl Rewrite for ast::GenericParam {
  mk_sp(last_attr.span.hi(), param_start),
  shape,
  !last_attr.is_doc_comment(),
- )?;
+ )
+ .unknown_error()?;
  } else {
  // When rewriting generic params, an extra newline should be put
  // if the attributes end with a doc comment
@@ -688,7 +711,7 @@ impl Rewrite for ast::GenericParam {
  result.push_str(&param);
  }
 
- Some(result)
+ Ok(result)
  }
 }
 
@@ -725,18 +748,18 @@ impl Rewrite for ast::Ty {
  ast::TyKind::TraitObject(ref bounds, tobj_syntax) => {
  // we have to consider 'dyn' keyword is used or not!!!
  let (shape, prefix) = match tobj_syntax {
- ast::TraitObjectSyntax::Dyn => (
- shape
+ ast::TraitObjectSyntax::Dyn => {
+ let shape = shape
  .offset_left(4)
- .max_width_error(shape.width, self.span())?,
- "dyn ",
- ),
- ast::TraitObjectSyntax::DynStar => (
- shape
+ .max_width_error(shape.width, self.span())?;
+ (shape, "dyn ")
+ }
+ ast::TraitObjectSyntax::DynStar => {
+ let shape = shape
  .offset_left(5)
- .max_width_error(shape.width, self.span())?,
- "dyn* ",
- ),
+ .max_width_error(shape.width, self.span())?;
+ (shape, "dyn* ")
+ }
  ast::TraitObjectSyntax::None => (shape, ""),
  };
  let mut res = bounds.rewrite_result(context, shape)?;
@@ -924,7 +947,7 @@ impl Rewrite for ast::Ty {
  let rw = if context.config.version() == Version::One {
  it.rewrite_result(context, shape)
  } else {
- join_bounds(context, shape, it, false).unknown_error()
+ join_bounds(context, shape, it, false)
  };
  rw.map(|it_str| {
  let space = if it_str.is_empty() { "" } else { " " };
@@ -1024,7 +1047,7 @@ fn join_bounds(
  shape: Shape,
  items: &[ast::GenericBound],
  need_indent: bool,
-) -> Option<String> {
+) -> RewriteResult {
  join_bounds_inner(context, shape, items, need_indent, false)
 }
 
@@ -1034,7 +1057,7 @@ fn join_bounds_inner(
  items: &[ast::GenericBound],
  need_indent: bool,
  force_newline: bool,
-) -> Option<String> {
+) -> RewriteResult {
  debug_assert!(!items.is_empty());
 
  let generic_bounds_in_order = is_generic_bounds_in_order(items);
@@ -1129,16 +1152,17 @@ fn join_bounds_inner(
  };
 
  let (extendable, trailing_str) = if i == 0 {
- let bound_str = item.rewrite(context, shape)?;
+ let bound_str = item.rewrite_result(context, shape)?;
  (is_bound_extendable(&bound_str, item), bound_str)
  } else {
- let bound_str = &item.rewrite(context, shape)?;
+ let bound_str = &item.rewrite_result(context, shape)?;
  match leading_span {
  Some(ls) if has_leading_comment => (
  is_bound_extendable(bound_str, item),
  combine_strs_with_missing_comments(
  context, joiner, bound_str, ls, shape, true,
- )?,
+ )
+ .unknown_error()?,
  ),
  _ => (
  is_bound_extendable(bound_str, item),
@@ -1155,8 +1179,9 @@ fn join_bounds_inner(
  shape,
  true,
  )
+ .unknown_error()
  .map(|v| (v, trailing_span, extendable)),
- _ => Some((strs + &trailing_str, trailing_span, extendable)),
+ _ => Ok((strs + &trailing_str, trailing_span, extendable)),
  }
  },
  )?;
@@ -1181,7 +1206,7 @@ fn join_bounds_inner(
  if retry_with_force_newline {
  join_bounds_inner(context, shape, items, need_indent, true)
  } else {
- Some(result.0)
+ Ok(result.0)
  }
 }