diff options
Diffstat (limited to 'src/expr.rs')
| -rw-r--r-- | src/expr.rs | 70 |
1 files changed, 40 insertions, 30 deletions
diff --git a/src/expr.rs b/src/expr.rs index 02372e7be13..35b7bada92d 100644 --- a/src/expr.rs +++ b/src/expr.rs @@ -194,10 +194,10 @@ pub(crate) fn format_expr( rewrite_path(context, PathContext::Expr, qself, path, shape).ok() } ast::ExprKind::Assign(ref lhs, ref rhs, _) => { - rewrite_assignment(context, lhs, rhs, None, shape) + rewrite_assignment(context, lhs, rhs, None, shape).ok() } ast::ExprKind::AssignOp(ref op, ref lhs, ref rhs) => { - rewrite_assignment(context, lhs, rhs, Some(op), shape) + rewrite_assignment(context, lhs, rhs, Some(op), shape).ok() } ast::ExprKind::Continue(ref opt_label) => { let id_str = match *opt_label { @@ -2050,15 +2050,21 @@ fn rewrite_assignment( rhs: &ast::Expr, op: Option<&ast::BinOp>, shape: Shape, -) -> Option<String> { +) -> RewriteResult { let operator_str = match op { Some(op) => context.snippet(op.span), None => "=", }; // 1 = space between lhs and operator. - let lhs_shape = shape.sub_width(operator_str.len() + 1)?; - let lhs_str = format!("{} {}", lhs.rewrite(context, lhs_shape)?, operator_str); + let lhs_shape = shape + .sub_width(operator_str.len() + 1) + .max_width_error(shape.width, lhs.span())?; + let lhs_str = format!( + "{} {}", + lhs.rewrite_result(context, lhs_shape)?, + operator_str + ); rewrite_assign_rhs( context, @@ -2089,7 +2095,7 @@ pub(crate) fn rewrite_assign_rhs<S: Into<String>, R: Rewrite>( ex: &R, rhs_kind: &RhsAssignKind<'_>, shape: Shape, -) -> Option<String> { +) -> RewriteResult { rewrite_assign_rhs_with(context, lhs, ex, shape, rhs_kind, RhsTactics::Default) } @@ -2100,7 +2106,7 @@ pub(crate) fn rewrite_assign_rhs_expr<R: Rewrite>( shape: Shape, rhs_kind: &RhsAssignKind<'_>, rhs_tactics: RhsTactics, -) -> Option<String> { +) -> RewriteResult { let last_line_width = last_line_width(lhs).saturating_sub(if lhs.contains('\n') { shape.indent.width() } else { @@ -2122,7 +2128,7 @@ pub(crate) fn rewrite_assign_rhs_expr<R: Rewrite>( context, ex, orig_shape, - ex.rewrite(context, orig_shape), + ex.rewrite_result(context, orig_shape), rhs_kind, rhs_tactics, has_rhs_comment, @@ -2136,10 +2142,10 @@ pub(crate) fn rewrite_assign_rhs_with<S: Into<String>, R: Rewrite>( shape: Shape, rhs_kind: &RhsAssignKind<'_>, rhs_tactics: RhsTactics, -) -> Option<String> { +) -> RewriteResult { let lhs = lhs.into(); let rhs = rewrite_assign_rhs_expr(context, &lhs, ex, shape, rhs_kind, rhs_tactics)?; - Some(lhs + &rhs) + Ok(lhs + &rhs) } pub(crate) fn rewrite_assign_rhs_with_comments<S: Into<String>, R: Rewrite + Spanned>( @@ -2161,8 +2167,7 @@ pub(crate) fn rewrite_assign_rhs_with_comments<S: Into<String>, R: Rewrite + Spa } else { shape }; - let rhs = - rewrite_assign_rhs_expr(context, &lhs, ex, shape, rhs_kind, rhs_tactics).unknown_error()?; + let rhs = rewrite_assign_rhs_expr(context, &lhs, ex, shape, rhs_kind, rhs_tactics)?; if contains_comment { let rhs = rhs.trim_start(); combine_strs_with_missing_comments(context, &lhs, rhs, between_span, shape, allow_extend) @@ -2175,23 +2180,25 @@ fn choose_rhs<R: Rewrite>( context: &RewriteContext<'_>, expr: &R, shape: Shape, - orig_rhs: Option<String>, + orig_rhs: RewriteResult, _rhs_kind: &RhsAssignKind<'_>, rhs_tactics: RhsTactics, has_rhs_comment: bool, -) -> Option<String> { +) -> RewriteResult { match orig_rhs { - Some(ref new_str) if new_str.is_empty() => Some(String::new()), - Some(ref new_str) - if !new_str.contains('\n') && unicode_str_width(new_str) <= shape.width => - { - Some(format!(" {new_str}")) + Ok(ref new_str) if new_str.is_empty() => Ok(String::new()), + Ok(ref new_str) if !new_str.contains('\n') && unicode_str_width(new_str) <= shape.width => { + Ok(format!(" {new_str}")) } _ => { // Expression did not fit on the same line as the identifier. // Try splitting the line and see if that works better. - let new_shape = shape_from_rhs_tactic(context, shape, rhs_tactics)?; - let new_rhs = expr.rewrite(context, new_shape); + let new_shape = shape_from_rhs_tactic(context, shape, rhs_tactics) + // TODO(ding-young) Ideally, we can replace unknown_error() with max_width_error(), + // but this requires either implementing the Spanned trait for ast::GenericBounds + // or grabbing the span from the call site. + .unknown_error()?; + let new_rhs = expr.rewrite_result(context, new_shape); let new_indent_str = &shape .indent .block_indent(context.config) @@ -2199,24 +2206,27 @@ fn choose_rhs<R: Rewrite>( let before_space_str = if has_rhs_comment { "" } else { " " }; match (orig_rhs, new_rhs) { - (Some(ref orig_rhs), Some(ref new_rhs)) + (Ok(ref orig_rhs), Ok(ref new_rhs)) if !filtered_str_fits(&new_rhs, context.config.max_width(), new_shape) => { - Some(format!("{before_space_str}{orig_rhs}")) + Ok(format!("{before_space_str}{orig_rhs}")) } - (Some(ref orig_rhs), Some(ref new_rhs)) + (Ok(ref orig_rhs), Ok(ref new_rhs)) if prefer_next_line(orig_rhs, new_rhs, rhs_tactics) => { - Some(format!("{new_indent_str}{new_rhs}")) + Ok(format!("{new_indent_str}{new_rhs}")) } - (None, Some(ref new_rhs)) => Some(format!("{new_indent_str}{new_rhs}")), - (None, None) if rhs_tactics == RhsTactics::AllowOverflow => { + (Err(_), Ok(ref new_rhs)) => Ok(format!("{new_indent_str}{new_rhs}")), + (Err(_), Err(_)) if rhs_tactics == RhsTactics::AllowOverflow => { let shape = shape.infinite_width(); - expr.rewrite(context, shape) + expr.rewrite_result(context, shape) .map(|s| format!("{}{}", before_space_str, s)) } - (None, None) => None, - (Some(orig_rhs), _) => Some(format!("{before_space_str}{orig_rhs}")), + // When both orig_rhs and new_rhs result in errors, we currently propagate + // the error from the second attempt since it is more generous with + // width constraints. This decision is somewhat arbitrary and is open to change. + (Err(_), Err(new_rhs_err)) => Err(new_rhs_err), + (Ok(orig_rhs), _) => Ok(format!("{before_space_str}{orig_rhs}")), } } } |