4b1c669037
* Add spaces_within_square_brackets config option. Enabling the config enforces spaces within various array/slice brackets. * Fixed budget-calculations for [] spacing
1991 lines
76 KiB
Rust
1991 lines
76 KiB
Rust
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use std::cmp::Ordering;
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use std::borrow::Borrow;
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use std::mem::swap;
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use std::ops::Deref;
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use std::iter::ExactSizeIterator;
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use std::fmt::Write;
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use {Indent, Spanned};
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use codemap::SpanUtils;
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use rewrite::{Rewrite, RewriteContext};
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use lists::{write_list, itemize_list, ListFormatting, SeparatorTactic, ListTactic,
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DefinitiveListTactic, definitive_tactic, ListItem, format_item_list};
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use string::{StringFormat, rewrite_string};
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use utils::{extra_offset, last_line_width, wrap_str, binary_search, first_line_width,
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semicolon_for_stmt, trimmed_last_line_width, left_most_sub_expr, stmt_block, stmt_expr};
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use visitor::FmtVisitor;
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use config::{Config, StructLitStyle, MultilineStyle, ElseIfBraceStyle, ControlBraceStyle};
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use comment::{FindUncommented, rewrite_comment, contains_comment, recover_comment_removed};
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use types::rewrite_path;
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use items::{span_lo_for_arg, span_hi_for_arg};
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use chains::rewrite_chain;
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use macros::rewrite_macro;
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use syntax::{ast, ptr};
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use syntax::codemap::{CodeMap, Span, BytePos, mk_sp};
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use syntax::parse::classify;
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impl Rewrite for ast::Expr {
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fn rewrite(&self, context: &RewriteContext, width: usize, offset: Indent) -> Option<String> {
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format_expr(self, ExprType::SubExpression, context, width, offset)
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}
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}
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#[derive(PartialEq)]
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enum ExprType {
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Statement,
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SubExpression,
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}
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fn format_expr(expr: &ast::Expr,
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expr_type: ExprType,
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context: &RewriteContext,
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width: usize,
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offset: Indent)
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-> Option<String> {
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let result = match expr.node {
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ast::ExprKind::Vec(ref expr_vec) => {
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rewrite_array(expr_vec.iter().map(|e| &**e),
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mk_sp(context.codemap.span_after(expr.span, "["), expr.span.hi),
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context,
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width,
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offset)
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}
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ast::ExprKind::Lit(ref l) => {
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match l.node {
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ast::LitKind::Str(_, ast::StrStyle::Cooked) => {
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rewrite_string_lit(context, l.span, width, offset)
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}
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_ => {
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wrap_str(context.snippet(expr.span),
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context.config.max_width,
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width,
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offset)
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}
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}
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}
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ast::ExprKind::Call(ref callee, ref args) => {
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let inner_span = mk_sp(callee.span.hi, expr.span.hi);
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rewrite_call(context, &**callee, args, inner_span, width, offset)
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}
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ast::ExprKind::Paren(ref subexpr) => rewrite_paren(context, subexpr, width, offset),
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ast::ExprKind::Binary(ref op, ref lhs, ref rhs) => {
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rewrite_binary_op(context, op, lhs, rhs, width, offset)
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}
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ast::ExprKind::Unary(ref op, ref subexpr) => {
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rewrite_unary_op(context, op, subexpr, width, offset)
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}
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ast::ExprKind::Struct(ref path, ref fields, ref base) => {
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rewrite_struct_lit(context,
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path,
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fields,
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base.as_ref().map(|e| &**e),
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expr.span,
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width,
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offset)
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}
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ast::ExprKind::Tup(ref items) => {
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rewrite_tuple(context,
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items.iter().map(|x| &**x),
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expr.span,
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width,
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offset)
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}
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ast::ExprKind::While(ref cond, ref block, label) => {
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Loop::new_while(None, cond, block, label).rewrite(context, width, offset)
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}
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ast::ExprKind::WhileLet(ref pat, ref cond, ref block, label) => {
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Loop::new_while(Some(pat), cond, block, label).rewrite(context, width, offset)
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}
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ast::ExprKind::ForLoop(ref pat, ref cond, ref block, label) => {
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Loop::new_for(pat, cond, block, label).rewrite(context, width, offset)
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}
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ast::ExprKind::Loop(ref block, label) => {
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Loop::new_loop(block, label).rewrite(context, width, offset)
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}
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ast::ExprKind::Block(ref block) => block.rewrite(context, width, offset),
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ast::ExprKind::If(ref cond, ref if_block, ref else_block) => {
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rewrite_if_else(context,
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cond,
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expr_type,
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if_block,
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else_block.as_ref().map(|e| &**e),
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expr.span,
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None,
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width,
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offset,
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true)
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}
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ast::ExprKind::IfLet(ref pat, ref cond, ref if_block, ref else_block) => {
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rewrite_if_else(context,
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cond,
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expr_type,
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if_block,
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else_block.as_ref().map(|e| &**e),
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expr.span,
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Some(pat),
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width,
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offset,
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true)
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}
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ast::ExprKind::Match(ref cond, ref arms) => {
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rewrite_match(context, cond, arms, width, offset, expr.span)
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}
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ast::ExprKind::Path(ref qself, ref path) => {
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rewrite_path(context, true, qself.as_ref(), path, width, offset)
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}
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ast::ExprKind::Assign(ref lhs, ref rhs) => {
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rewrite_assignment(context, lhs, rhs, None, width, offset)
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}
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ast::ExprKind::AssignOp(ref op, ref lhs, ref rhs) => {
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rewrite_assignment(context, lhs, rhs, Some(op), width, offset)
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}
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ast::ExprKind::Continue(ref opt_ident) => {
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let id_str = match *opt_ident {
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Some(ident) => format!(" {}", ident.node),
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None => String::new(),
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};
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wrap_str(format!("continue{}", id_str),
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context.config.max_width,
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width,
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offset)
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}
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ast::ExprKind::Break(ref opt_ident) => {
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let id_str = match *opt_ident {
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Some(ident) => format!(" {}", ident.node),
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None => String::new(),
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};
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wrap_str(format!("break{}", id_str),
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context.config.max_width,
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width,
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offset)
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}
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ast::ExprKind::Closure(capture, ref fn_decl, ref body, _) => {
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rewrite_closure(capture, fn_decl, body, expr.span, context, width, offset)
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}
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ast::ExprKind::Try(..) |
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ast::ExprKind::Field(..) |
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ast::ExprKind::TupField(..) |
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ast::ExprKind::MethodCall(..) => rewrite_chain(expr, context, width, offset),
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ast::ExprKind::Mac(ref mac) => {
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// Failure to rewrite a marco should not imply failure to
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// rewrite the expression.
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rewrite_macro(mac, None, context, width, offset).or_else(|| {
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wrap_str(context.snippet(expr.span),
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context.config.max_width,
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width,
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offset)
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})
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}
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ast::ExprKind::Ret(None) => {
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wrap_str("return".to_owned(), context.config.max_width, width, offset)
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}
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ast::ExprKind::Ret(Some(ref expr)) => {
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rewrite_unary_prefix(context, "return ", &**expr, width, offset)
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}
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ast::ExprKind::Box(ref expr) => {
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rewrite_unary_prefix(context, "box ", &**expr, width, offset)
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}
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ast::ExprKind::AddrOf(mutability, ref expr) => {
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rewrite_expr_addrof(context, mutability, expr, width, offset)
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}
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ast::ExprKind::Cast(ref expr, ref ty) => {
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rewrite_pair(&**expr, &**ty, "", " as ", "", context, width, offset)
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}
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ast::ExprKind::Type(ref expr, ref ty) => {
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rewrite_pair(&**expr, &**ty, "", ": ", "", context, width, offset)
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}
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ast::ExprKind::Index(ref expr, ref index) => {
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let use_spaces = context.config.spaces_within_square_brackets;
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let lbr = if use_spaces { "[ " } else { "[" };
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let rbr = if use_spaces { " ]" } else { "]" };
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rewrite_pair(&**expr, &**index, "", lbr, rbr, context, width, offset)
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}
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ast::ExprKind::Repeat(ref expr, ref repeats) => {
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let use_spaces = context.config.spaces_within_square_brackets;
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let lbr = if use_spaces { "[ " } else { "[" };
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let rbr = if use_spaces { " ]" } else { "]" };
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rewrite_pair(&**expr, &**repeats, lbr, "; ", rbr, context, width, offset)
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}
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ast::ExprKind::Range(ref lhs, ref rhs, limits) => {
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let delim = match limits {
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ast::RangeLimits::HalfOpen => "..",
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ast::RangeLimits::Closed => "...",
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};
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match (lhs.as_ref().map(|x| &**x), rhs.as_ref().map(|x| &**x)) {
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(Some(ref lhs), Some(ref rhs)) => {
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let sp_delim = if context.config.spaces_around_ranges {
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format!(" {} ", delim)
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} else {
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delim.into()
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};
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rewrite_pair(&**lhs, &**rhs, "", &sp_delim, "", context, width, offset)
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}
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(None, Some(ref rhs)) => {
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let sp_delim = if context.config.spaces_around_ranges {
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format!("{} ", delim)
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} else {
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delim.into()
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};
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rewrite_unary_prefix(context, &sp_delim, &**rhs, width, offset)
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}
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(Some(ref lhs), None) => {
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let sp_delim = if context.config.spaces_around_ranges {
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format!(" {}", delim)
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} else {
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delim.into()
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};
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rewrite_unary_suffix(context, &sp_delim, &**lhs, width, offset)
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}
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(None, None) => wrap_str(delim.into(), context.config.max_width, width, offset),
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}
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}
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// We do not format these expressions yet, but they should still
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// satisfy our width restrictions.
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ast::ExprKind::InPlace(..) |
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ast::ExprKind::InlineAsm(..) => {
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wrap_str(context.snippet(expr.span),
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context.config.max_width,
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width,
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offset)
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}
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};
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result.and_then(|res| recover_comment_removed(res, expr.span, context, width, offset))
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}
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pub fn rewrite_pair<LHS, RHS>(lhs: &LHS,
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rhs: &RHS,
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prefix: &str,
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infix: &str,
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suffix: &str,
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context: &RewriteContext,
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width: usize,
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offset: Indent)
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-> Option<String>
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where LHS: Rewrite,
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RHS: Rewrite
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{
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let max_width = try_opt!(width.checked_sub(prefix.len() + infix.len() + suffix.len()));
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binary_search(1, max_width, |lhs_budget| {
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let lhs_offset = offset + prefix.len();
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let lhs_str = match lhs.rewrite(context, lhs_budget, lhs_offset) {
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Some(result) => result,
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None => return Err(Ordering::Greater),
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};
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let last_line_width = last_line_width(&lhs_str);
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let rhs_budget = match max_width.checked_sub(last_line_width) {
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Some(b) => b,
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None => return Err(Ordering::Less),
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};
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let rhs_indent = offset + last_line_width + prefix.len() + infix.len();
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let rhs_str = match rhs.rewrite(context, rhs_budget, rhs_indent) {
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Some(result) => result,
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None => return Err(Ordering::Less),
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};
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Ok(format!("{}{}{}{}{}", prefix, lhs_str, infix, rhs_str, suffix))
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})
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}
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pub fn rewrite_array<'a, I>(expr_iter: I,
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span: Span,
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context: &RewriteContext,
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width: usize,
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offset: Indent)
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-> Option<String>
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where I: Iterator<Item = &'a ast::Expr>
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{
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let bracket_size = if context.config.spaces_within_square_brackets {
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2 // "[ "
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} else {
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1 // "["
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};
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let offset = offset + bracket_size;
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let inner_context = &RewriteContext { block_indent: offset, ..*context };
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let max_item_width = try_opt!(width.checked_sub(bracket_size * 2));
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let items = itemize_list(context.codemap,
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expr_iter,
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"]",
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|item| item.span.lo,
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|item| item.span.hi,
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|item| item.rewrite(inner_context, max_item_width, offset),
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span.lo,
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span.hi)
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.collect::<Vec<_>>();
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let has_long_item = try_opt!(items.iter()
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.map(|li| li.item.as_ref().map(|s| s.len() > 10))
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.fold(Some(false), |acc, x| acc.and_then(|y| x.map(|x| x || y))));
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let tactic = if has_long_item || items.iter().any(ListItem::is_multiline) {
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definitive_tactic(&items, ListTactic::HorizontalVertical, max_item_width)
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} else {
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DefinitiveListTactic::Mixed
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};
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let fmt = ListFormatting {
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tactic: tactic,
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separator: ",",
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trailing_separator: SeparatorTactic::Never,
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indent: offset,
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width: max_item_width,
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ends_with_newline: false,
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config: context.config,
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};
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let list_str = try_opt!(write_list(&items, &fmt));
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Some(if context.config.spaces_within_square_brackets && list_str.len() > 0 {
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format!("[ {} ]", list_str)
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} else {
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format!("[{}]", list_str)
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})
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}
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// This functions is pretty messy because of the rules around closures and blocks:
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// * the body of a closure is represented by an ast::Block, but that does not
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// imply there are `{}` (unless the block is empty) (see rust issue #27872),
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// * if there is a return type, then there must be braces,
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// * given a closure with braces, whether that is parsed to give an inner block
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// or not depends on if there is a return type and if there are statements
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// in that block,
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// * if the first expression in the body ends with a block (i.e., is a
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// statement without needing a semi-colon), then adding or removing braces
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// can change whether it is treated as an expression or statement.
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fn rewrite_closure(capture: ast::CaptureBy,
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fn_decl: &ast::FnDecl,
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body: &ast::Block,
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span: Span,
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context: &RewriteContext,
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width: usize,
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offset: Indent)
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-> Option<String> {
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let mover = if capture == ast::CaptureBy::Value {
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"move "
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} else {
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""
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};
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let offset = offset + mover.len();
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// 4 = "|| {".len(), which is overconservative when the closure consists of
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// a single expression.
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let budget = try_opt!(width.checked_sub(4 + mover.len()));
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// 1 = |
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let argument_offset = offset + 1;
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let ret_str = try_opt!(fn_decl.output.rewrite(context, budget, argument_offset));
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let force_block = !ret_str.is_empty();
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// 1 = space between arguments and return type.
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let horizontal_budget = budget.checked_sub(ret_str.len() + 1).unwrap_or(0);
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let arg_items = itemize_list(context.codemap,
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fn_decl.inputs.iter(),
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"|",
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|arg| span_lo_for_arg(arg),
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|arg| span_hi_for_arg(arg),
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|arg| arg.rewrite(context, budget, argument_offset),
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context.codemap.span_after(span, "|"),
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body.span.lo);
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let item_vec = arg_items.collect::<Vec<_>>();
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let tactic = definitive_tactic(&item_vec, ListTactic::HorizontalVertical, horizontal_budget);
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let budget = match tactic {
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DefinitiveListTactic::Horizontal => horizontal_budget,
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_ => budget,
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};
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let fmt = ListFormatting {
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tactic: tactic,
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separator: ",",
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trailing_separator: SeparatorTactic::Never,
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indent: argument_offset,
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width: budget,
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ends_with_newline: false,
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config: context.config,
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};
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let list_str = try_opt!(write_list(&item_vec, &fmt));
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let mut prefix = format!("{}|{}|", mover, list_str);
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if !ret_str.is_empty() {
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if prefix.contains('\n') {
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prefix.push('\n');
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prefix.push_str(&argument_offset.to_string(context.config));
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} else {
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prefix.push(' ');
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}
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prefix.push_str(&ret_str);
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}
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if body.stmts.is_empty() {
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return Some(format!("{} {{}}", prefix));
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}
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// 1 = space between `|...|` and body.
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let extra_offset = extra_offset(&prefix, offset) + 1;
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let budget = try_opt!(width.checked_sub(extra_offset));
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// This is where we figure out whether to use braces or not.
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let mut had_braces = true;
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let mut inner_block = body;
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let mut trailing_expr = stmt_expr(&inner_block.stmts[inner_block.stmts.len() - 1]);
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// If there is an inner block and we can ignore it, do so.
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if body.stmts.len() == 1 && trailing_expr.is_some() {
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if let Some(ref inner) = stmt_block(&inner_block.stmts[0]) {
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inner_block = inner;
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trailing_expr = if inner_block.stmts.is_empty() {
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None
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} else {
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stmt_expr(&inner_block.stmts[inner_block.stmts.len() - 1])
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};
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} else if !force_block {
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had_braces = false;
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}
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}
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let try_single_line = is_simple_block(inner_block, context.codemap) &&
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inner_block.rules == ast::BlockCheckMode::Default;
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if try_single_line && !force_block {
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let must_preserve_braces =
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trailing_expr.is_none() ||
|
|
!classify::expr_requires_semi_to_be_stmt(left_most_sub_expr(trailing_expr.unwrap()));
|
|
if !(must_preserve_braces && had_braces) &&
|
|
(must_preserve_braces || !prefix.contains('\n')) {
|
|
// If we got here, then we can try to format without braces.
|
|
|
|
let inner_expr = &inner_block.stmts[0];
|
|
let mut rewrite = inner_expr.rewrite(context, budget, offset + extra_offset);
|
|
|
|
if must_preserve_braces {
|
|
// If we are here, then failure to rewrite is unacceptable.
|
|
if rewrite.is_none() {
|
|
return None;
|
|
}
|
|
} else {
|
|
// Checks if rewrite succeeded and fits on a single line.
|
|
rewrite = and_one_line(rewrite);
|
|
}
|
|
|
|
if let Some(rewrite) = rewrite {
|
|
return Some(format!("{} {}", prefix, rewrite));
|
|
}
|
|
}
|
|
}
|
|
|
|
// If we fell through the above block, then we need braces, but we might
|
|
// still prefer a one-liner (we might also have fallen through because of
|
|
// lack of space).
|
|
if try_single_line && !prefix.contains('\n') {
|
|
let inner_expr = &inner_block.stmts[0];
|
|
// 4 = braces and spaces.
|
|
let mut rewrite = inner_expr.rewrite(context,
|
|
try_opt!(budget.checked_sub(4)),
|
|
offset + extra_offset);
|
|
|
|
// Checks if rewrite succeeded and fits on a single line.
|
|
rewrite = and_one_line(rewrite);
|
|
|
|
if let Some(rewrite) = rewrite {
|
|
return Some(format!("{} {{ {} }}", prefix, rewrite));
|
|
}
|
|
}
|
|
|
|
// We couldn't format the closure body as a single line expression; fall
|
|
// back to block formatting.
|
|
let body_rewrite = try_opt!(inner_block.rewrite(&context, budget, Indent::empty()));
|
|
|
|
let block_threshold = context.config.closure_block_indent_threshold;
|
|
if block_threshold < 0 || body_rewrite.matches('\n').count() <= block_threshold as usize {
|
|
return Some(format!("{} {}", prefix, body_rewrite));
|
|
}
|
|
|
|
// The body of the closure is big enough to be block indented, that means we
|
|
// must re-format.
|
|
let mut context = context.clone();
|
|
context.block_indent.alignment = 0;
|
|
let body_rewrite = try_opt!(inner_block.rewrite(&context, budget, Indent::empty()));
|
|
Some(format!("{} {}", prefix, body_rewrite))
|
|
}
|
|
|
|
fn and_one_line(x: Option<String>) -> Option<String> {
|
|
x.and_then(|x| if x.contains('\n') { None } else { Some(x) })
|
|
}
|
|
|
|
fn nop_block_collapse(block_str: Option<String>, budget: usize) -> Option<String> {
|
|
block_str.map(|block_str| {
|
|
if block_str.starts_with('{') && budget >= 2 &&
|
|
(block_str[1..].find(|c: char| !c.is_whitespace()).unwrap() == block_str.len() - 2) {
|
|
"{}".to_owned()
|
|
} else {
|
|
block_str.to_owned()
|
|
}
|
|
})
|
|
}
|
|
|
|
impl Rewrite for ast::Block {
|
|
fn rewrite(&self, context: &RewriteContext, width: usize, offset: Indent) -> Option<String> {
|
|
// width is used only for the single line case: either the empty block `{}`,
|
|
// or an unsafe expression `unsafe { e }`.
|
|
|
|
let user_str = context.snippet(self.span);
|
|
if user_str == "{}" && width >= 2 {
|
|
return Some(user_str);
|
|
}
|
|
|
|
let mut visitor = FmtVisitor::from_codemap(context.parse_session, context.config);
|
|
visitor.block_indent = context.block_indent;
|
|
|
|
let prefix = match self.rules {
|
|
ast::BlockCheckMode::Unsafe(..) => {
|
|
let snippet = context.snippet(self.span);
|
|
let open_pos = try_opt!(snippet.find_uncommented("{"));
|
|
visitor.last_pos = self.span.lo + BytePos(open_pos as u32);
|
|
|
|
// Extract comment between unsafe and block start.
|
|
let trimmed = &snippet[6..open_pos].trim();
|
|
|
|
let prefix = if !trimmed.is_empty() {
|
|
// 9 = "unsafe {".len(), 7 = "unsafe ".len()
|
|
let budget = try_opt!(width.checked_sub(9));
|
|
format!("unsafe {} ",
|
|
try_opt!(rewrite_comment(trimmed,
|
|
true,
|
|
budget,
|
|
offset + 7,
|
|
context.config)))
|
|
} else {
|
|
"unsafe ".to_owned()
|
|
};
|
|
|
|
if is_simple_block(self, context.codemap) && prefix.len() < width {
|
|
let expr_str = self.stmts[0].rewrite(context, width - prefix.len(), offset);
|
|
let expr_str = try_opt!(expr_str);
|
|
let result = format!("{}{{ {} }}", prefix, expr_str);
|
|
if result.len() <= width && !result.contains('\n') {
|
|
return Some(result);
|
|
}
|
|
}
|
|
|
|
prefix
|
|
}
|
|
ast::BlockCheckMode::Default => {
|
|
visitor.last_pos = self.span.lo;
|
|
|
|
String::new()
|
|
}
|
|
};
|
|
|
|
visitor.visit_block(self);
|
|
|
|
Some(format!("{}{}", prefix, visitor.buffer))
|
|
}
|
|
}
|
|
|
|
impl Rewrite for ast::Stmt {
|
|
fn rewrite(&self, context: &RewriteContext, _width: usize, offset: Indent) -> Option<String> {
|
|
let result = match self.node {
|
|
ast::StmtKind::Local(ref local) => {
|
|
local.rewrite(context, context.config.max_width, offset)
|
|
}
|
|
ast::StmtKind::Expr(ref ex) |
|
|
ast::StmtKind::Semi(ref ex) => {
|
|
let suffix = if semicolon_for_stmt(self) { ";" } else { "" };
|
|
|
|
format_expr(ex,
|
|
match self.node {
|
|
ast::StmtKind::Expr(_) => ExprType::SubExpression,
|
|
ast::StmtKind::Semi(_) => ExprType::Statement,
|
|
_ => unreachable!(),
|
|
},
|
|
context,
|
|
context.config.max_width - offset.width() - suffix.len(),
|
|
offset)
|
|
.map(|s| s + suffix)
|
|
}
|
|
ast::StmtKind::Mac(..) |
|
|
ast::StmtKind::Item(..) => None,
|
|
};
|
|
result.and_then(|res| recover_comment_removed(res, self.span, context, _width, offset))
|
|
}
|
|
}
|
|
|
|
// Abstraction over for, while and loop expressions
|
|
struct Loop<'a> {
|
|
cond: Option<&'a ast::Expr>,
|
|
block: &'a ast::Block,
|
|
label: Option<ast::SpannedIdent>,
|
|
pat: Option<&'a ast::Pat>,
|
|
keyword: &'a str,
|
|
matcher: &'a str,
|
|
connector: &'a str,
|
|
}
|
|
|
|
impl<'a> Loop<'a> {
|
|
fn new_loop(block: &'a ast::Block, label: Option<ast::SpannedIdent>) -> Loop<'a> {
|
|
Loop {
|
|
cond: None,
|
|
block: block,
|
|
label: label,
|
|
pat: None,
|
|
keyword: "loop",
|
|
matcher: "",
|
|
connector: "",
|
|
}
|
|
}
|
|
|
|
fn new_while(pat: Option<&'a ast::Pat>,
|
|
cond: &'a ast::Expr,
|
|
block: &'a ast::Block,
|
|
label: Option<ast::SpannedIdent>)
|
|
-> Loop<'a> {
|
|
Loop {
|
|
cond: Some(cond),
|
|
block: block,
|
|
label: label,
|
|
pat: pat,
|
|
keyword: "while ",
|
|
matcher: match pat {
|
|
Some(..) => "let ",
|
|
None => "",
|
|
},
|
|
connector: " =",
|
|
}
|
|
}
|
|
|
|
fn new_for(pat: &'a ast::Pat,
|
|
cond: &'a ast::Expr,
|
|
block: &'a ast::Block,
|
|
label: Option<ast::SpannedIdent>)
|
|
-> Loop<'a> {
|
|
Loop {
|
|
cond: Some(cond),
|
|
block: block,
|
|
label: label,
|
|
pat: Some(pat),
|
|
keyword: "for ",
|
|
matcher: "",
|
|
connector: " in",
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a> Rewrite for Loop<'a> {
|
|
fn rewrite(&self, context: &RewriteContext, width: usize, offset: Indent) -> Option<String> {
|
|
let label_string = rewrite_label(self.label);
|
|
// 2 = " {".len()
|
|
let inner_width = try_opt!(width.checked_sub(self.keyword.len() + 2 + label_string.len()));
|
|
let inner_offset = offset + self.keyword.len() + label_string.len();
|
|
|
|
let pat_expr_string = match self.cond {
|
|
Some(cond) => {
|
|
try_opt!(rewrite_pat_expr(context,
|
|
self.pat,
|
|
cond,
|
|
self.matcher,
|
|
self.connector,
|
|
inner_width,
|
|
inner_offset))
|
|
}
|
|
None => String::new(),
|
|
};
|
|
|
|
let alt_block_sep = String::from("\n") + &context.block_indent.to_string(context.config);
|
|
let block_sep = match context.config.control_brace_style {
|
|
ControlBraceStyle::AlwaysNextLine => alt_block_sep.as_str(),
|
|
ControlBraceStyle::AlwaysSameLine => " ",
|
|
};
|
|
|
|
// This is used only for the empty block case: `{}`
|
|
let block_width = try_opt!(width.checked_sub(label_string.len() + self.keyword.len() +
|
|
extra_offset(&pat_expr_string, inner_offset) +
|
|
1));
|
|
|
|
// FIXME: this drops any comment between "loop" and the block.
|
|
self.block
|
|
.rewrite(context, block_width, offset)
|
|
.map(|result| {
|
|
format!("{}{}{}{}{}",
|
|
label_string,
|
|
self.keyword,
|
|
pat_expr_string,
|
|
block_sep,
|
|
result)
|
|
})
|
|
}
|
|
}
|
|
|
|
fn rewrite_label(label: Option<ast::SpannedIdent>) -> String {
|
|
match label {
|
|
Some(ident) => format!("{}: ", ident.node),
|
|
None => "".to_owned(),
|
|
}
|
|
}
|
|
|
|
fn extract_comment(span: Span,
|
|
context: &RewriteContext,
|
|
offset: Indent,
|
|
width: usize)
|
|
-> Option<String> {
|
|
let comment_str = context.snippet(span);
|
|
if contains_comment(&comment_str) {
|
|
let comment =
|
|
try_opt!(rewrite_comment(comment_str.trim(), false, width, offset, context.config));
|
|
Some(format!("\n{indent}{}\n{indent}",
|
|
comment,
|
|
indent = offset.to_string(context.config)))
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
// Rewrites if-else blocks. If let Some(_) = pat, the expression is
|
|
// treated as an if-let-else expression.
|
|
fn rewrite_if_else(context: &RewriteContext,
|
|
cond: &ast::Expr,
|
|
expr_type: ExprType,
|
|
if_block: &ast::Block,
|
|
else_block_opt: Option<&ast::Expr>,
|
|
span: Span,
|
|
pat: Option<&ast::Pat>,
|
|
width: usize,
|
|
offset: Indent,
|
|
allow_single_line: bool)
|
|
-> Option<String> {
|
|
let (budget, indent) = if !allow_single_line {
|
|
// We are part of an if-elseif-else chain. Our constraints are tightened.
|
|
// 7 = "} else" .len()
|
|
(try_opt!(width.checked_sub(7)), offset + 7)
|
|
} else {
|
|
(width, offset)
|
|
};
|
|
|
|
// 3 = "if ", 2 = " {"
|
|
let pat_penalty = match context.config.else_if_brace_style {
|
|
ElseIfBraceStyle::AlwaysNextLine => 3,
|
|
_ => 3 + 2,
|
|
};
|
|
let pat_expr_string = try_opt!(rewrite_pat_expr(context,
|
|
pat,
|
|
cond,
|
|
"let ",
|
|
" =",
|
|
try_opt!(budget.checked_sub(pat_penalty)),
|
|
indent + 3));
|
|
|
|
// Try to format if-else on single line.
|
|
if expr_type == ExprType::SubExpression && allow_single_line &&
|
|
context.config.single_line_if_else_max_width > 0 {
|
|
let trial = single_line_if_else(context, &pat_expr_string, if_block, else_block_opt, width);
|
|
|
|
if trial.is_some() &&
|
|
trial.as_ref().unwrap().len() <= context.config.single_line_if_else_max_width {
|
|
return trial;
|
|
}
|
|
}
|
|
|
|
let if_block_string = try_opt!(if_block.rewrite(context, width, offset));
|
|
|
|
let between_if_cond = mk_sp(context.codemap.span_after(span, "if"),
|
|
pat.map_or(cond.span.lo,
|
|
|_| context.codemap.span_before(span, "let")));
|
|
|
|
let between_if_cond_comment = extract_comment(between_if_cond, context, offset, width);
|
|
|
|
let after_cond_comment = extract_comment(mk_sp(cond.span.hi, if_block.span.lo),
|
|
context,
|
|
offset,
|
|
width);
|
|
|
|
let alt_block_sep = String::from("\n") + &context.block_indent.to_string(context.config);
|
|
let after_sep = match context.config.else_if_brace_style {
|
|
ElseIfBraceStyle::AlwaysNextLine => alt_block_sep.as_str(),
|
|
_ => " ",
|
|
};
|
|
let mut result = format!("if{}{}{}{}",
|
|
between_if_cond_comment.as_ref().map_or(" ", |str| &**str),
|
|
pat_expr_string,
|
|
after_cond_comment.as_ref().map_or(after_sep, |str| &**str),
|
|
if_block_string);
|
|
|
|
if let Some(else_block) = else_block_opt {
|
|
let mut last_in_chain = false;
|
|
let rewrite = match else_block.node {
|
|
// If the else expression is another if-else expression, prevent it
|
|
// from being formatted on a single line.
|
|
// Note how we're passing the original width and offset, as the
|
|
// cost of "else" should not cascade.
|
|
ast::ExprKind::IfLet(ref pat, ref cond, ref if_block, ref next_else_block) => {
|
|
rewrite_if_else(context,
|
|
cond,
|
|
expr_type,
|
|
if_block,
|
|
next_else_block.as_ref().map(|e| &**e),
|
|
mk_sp(else_block.span.lo, span.hi),
|
|
Some(pat),
|
|
width,
|
|
offset,
|
|
false)
|
|
}
|
|
ast::ExprKind::If(ref cond, ref if_block, ref next_else_block) => {
|
|
rewrite_if_else(context,
|
|
cond,
|
|
expr_type,
|
|
if_block,
|
|
next_else_block.as_ref().map(|e| &**e),
|
|
mk_sp(else_block.span.lo, span.hi),
|
|
None,
|
|
width,
|
|
offset,
|
|
false)
|
|
}
|
|
_ => {
|
|
last_in_chain = true;
|
|
else_block.rewrite(context, width, offset)
|
|
}
|
|
};
|
|
|
|
let between_if_else_block =
|
|
mk_sp(if_block.span.hi,
|
|
context.codemap.span_before(mk_sp(if_block.span.hi, else_block.span.lo), "else"));
|
|
let between_if_else_block_comment =
|
|
extract_comment(between_if_else_block, context, offset, width);
|
|
|
|
let after_else = mk_sp(context.codemap
|
|
.span_after(mk_sp(if_block.span.hi, else_block.span.lo),
|
|
"else"),
|
|
else_block.span.lo);
|
|
let after_else_comment = extract_comment(after_else, context, offset, width);
|
|
|
|
let between_sep = match context.config.else_if_brace_style {
|
|
ElseIfBraceStyle::AlwaysNextLine |
|
|
ElseIfBraceStyle::ClosingNextLine => alt_block_sep.as_str(),
|
|
ElseIfBraceStyle::AlwaysSameLine => " ",
|
|
};
|
|
let after_sep = match context.config.else_if_brace_style {
|
|
ElseIfBraceStyle::AlwaysNextLine if last_in_chain => alt_block_sep.as_str(),
|
|
_ => " ",
|
|
};
|
|
try_opt!(write!(&mut result,
|
|
"{}else{}",
|
|
between_if_else_block_comment.as_ref()
|
|
.map_or(between_sep, |str| &**str),
|
|
after_else_comment.as_ref().map_or(after_sep, |str| &**str))
|
|
.ok());
|
|
result.push_str(&try_opt!(rewrite));
|
|
}
|
|
|
|
Some(result)
|
|
}
|
|
|
|
fn single_line_if_else(context: &RewriteContext,
|
|
pat_expr_str: &str,
|
|
if_node: &ast::Block,
|
|
else_block_opt: Option<&ast::Expr>,
|
|
width: usize)
|
|
-> Option<String> {
|
|
let else_block = try_opt!(else_block_opt);
|
|
let fixed_cost = "if { } else { }".len();
|
|
|
|
if let ast::ExprKind::Block(ref else_node) = else_block.node {
|
|
if !is_simple_block(if_node, context.codemap) ||
|
|
!is_simple_block(else_node, context.codemap) || pat_expr_str.contains('\n') {
|
|
return None;
|
|
}
|
|
|
|
let new_width = try_opt!(width.checked_sub(pat_expr_str.len() + fixed_cost));
|
|
let if_expr = &if_node.stmts[0];
|
|
let if_str = try_opt!(if_expr.rewrite(context, new_width, Indent::empty()));
|
|
|
|
let new_width = try_opt!(new_width.checked_sub(if_str.len()));
|
|
let else_expr = &else_node.stmts[0];
|
|
let else_str = try_opt!(else_expr.rewrite(context, new_width, Indent::empty()));
|
|
|
|
// FIXME: this check shouldn't be necessary. Rewrites should either fail
|
|
// or wrap to a newline when the object does not fit the width.
|
|
let fits_line = fixed_cost + pat_expr_str.len() + if_str.len() + else_str.len() <= width;
|
|
|
|
if fits_line && !if_str.contains('\n') && !else_str.contains('\n') {
|
|
return Some(format!("if {} {{ {} }} else {{ {} }}",
|
|
pat_expr_str,
|
|
if_str,
|
|
else_str));
|
|
}
|
|
}
|
|
|
|
None
|
|
}
|
|
|
|
fn block_contains_comment(block: &ast::Block, codemap: &CodeMap) -> bool {
|
|
let snippet = codemap.span_to_snippet(block.span).unwrap();
|
|
contains_comment(&snippet)
|
|
}
|
|
|
|
// Checks that a block contains no statements, an expression and no comments.
|
|
// FIXME: incorrectly returns false when comment is contained completely within
|
|
// the expression.
|
|
pub fn is_simple_block(block: &ast::Block, codemap: &CodeMap) -> bool {
|
|
block.stmts.len() == 1 && stmt_is_expr(&block.stmts[0]) &&
|
|
!block_contains_comment(block, codemap)
|
|
}
|
|
|
|
/// Checks whether a block contains at most one statement or expression, and no comments.
|
|
pub fn is_simple_block_stmt(block: &ast::Block, codemap: &CodeMap) -> bool {
|
|
block.stmts.len() <= 1 && !block_contains_comment(block, codemap)
|
|
}
|
|
|
|
/// Checks whether a block contains no statements, expressions, or comments.
|
|
pub fn is_empty_block(block: &ast::Block, codemap: &CodeMap) -> bool {
|
|
block.stmts.is_empty() && !block_contains_comment(block, codemap)
|
|
}
|
|
|
|
pub fn stmt_is_expr(stmt: &ast::Stmt) -> bool {
|
|
match stmt.node {
|
|
ast::StmtKind::Expr(..) => true,
|
|
_ => false,
|
|
}
|
|
}
|
|
|
|
fn is_unsafe_block(block: &ast::Block) -> bool {
|
|
if let ast::BlockCheckMode::Unsafe(..) = block.rules {
|
|
true
|
|
} else {
|
|
false
|
|
}
|
|
}
|
|
|
|
// inter-match-arm-comment-rules:
|
|
// - all comments following a match arm before the start of the next arm
|
|
// are about the second arm
|
|
fn rewrite_match_arm_comment(context: &RewriteContext,
|
|
missed_str: &str,
|
|
width: usize,
|
|
arm_indent: Indent,
|
|
arm_indent_str: &str)
|
|
-> Option<String> {
|
|
// The leading "," is not part of the arm-comment
|
|
let missed_str = match missed_str.find_uncommented(",") {
|
|
Some(n) => &missed_str[n + 1..],
|
|
None => &missed_str[..],
|
|
};
|
|
|
|
let mut result = String::new();
|
|
// any text not preceeded by a newline is pushed unmodified to the block
|
|
let first_brk = missed_str.find(|c: char| c == '\n').unwrap_or(0);
|
|
result.push_str(&missed_str[..first_brk]);
|
|
let missed_str = &missed_str[first_brk..]; // If missed_str had one newline, it starts with it
|
|
|
|
let first = missed_str.find(|c: char| !c.is_whitespace()).unwrap_or(missed_str.len());
|
|
if missed_str[..first].chars().filter(|c| c == &'\n').count() >= 2 {
|
|
// Excessive vertical whitespace before comment should be preserved
|
|
// TODO handle vertical whitespace better
|
|
result.push('\n');
|
|
}
|
|
let missed_str = missed_str[first..].trim();
|
|
if !missed_str.is_empty() {
|
|
let comment =
|
|
try_opt!(rewrite_comment(&missed_str, false, width, arm_indent, context.config));
|
|
result.push('\n');
|
|
result.push_str(arm_indent_str);
|
|
result.push_str(&comment);
|
|
}
|
|
|
|
Some(result)
|
|
}
|
|
|
|
fn rewrite_match(context: &RewriteContext,
|
|
cond: &ast::Expr,
|
|
arms: &[ast::Arm],
|
|
width: usize,
|
|
offset: Indent,
|
|
span: Span)
|
|
-> Option<String> {
|
|
if arms.is_empty() {
|
|
return None;
|
|
}
|
|
|
|
// `match `cond` {`
|
|
let cond_budget = try_opt!(width.checked_sub(8));
|
|
let cond_str = try_opt!(cond.rewrite(context, cond_budget, offset + 6));
|
|
let alt_block_sep = String::from("\n") + &context.block_indent.to_string(context.config);
|
|
let block_sep = match context.config.control_brace_style {
|
|
ControlBraceStyle::AlwaysSameLine => " ",
|
|
ControlBraceStyle::AlwaysNextLine => alt_block_sep.as_str(),
|
|
};
|
|
let mut result = format!("match {}{}{{", cond_str, block_sep);
|
|
|
|
let nested_context = context.nested_context();
|
|
let arm_indent = nested_context.block_indent;
|
|
let arm_indent_str = arm_indent.to_string(context.config);
|
|
|
|
let open_brace_pos = context.codemap
|
|
.span_after(mk_sp(cond.span.hi, arm_start_pos(&arms[0])), "{");
|
|
|
|
for (i, arm) in arms.iter().enumerate() {
|
|
// Make sure we get the stuff between arms.
|
|
let missed_str = if i == 0 {
|
|
context.snippet(mk_sp(open_brace_pos, arm_start_pos(arm)))
|
|
} else {
|
|
context.snippet(mk_sp(arm_end_pos(&arms[i - 1]), arm_start_pos(arm)))
|
|
};
|
|
let comment = try_opt!(rewrite_match_arm_comment(context,
|
|
&missed_str,
|
|
width,
|
|
arm_indent,
|
|
&arm_indent_str));
|
|
result.push_str(&comment);
|
|
result.push('\n');
|
|
result.push_str(&arm_indent_str);
|
|
|
|
let arm_str = arm.rewrite(&nested_context,
|
|
context.config.max_width - arm_indent.width(),
|
|
arm_indent);
|
|
if let Some(ref arm_str) = arm_str {
|
|
result.push_str(arm_str);
|
|
} else {
|
|
// We couldn't format the arm, just reproduce the source.
|
|
let snippet = context.snippet(mk_sp(arm_start_pos(arm), arm_end_pos(arm)));
|
|
result.push_str(&snippet);
|
|
result.push_str(arm_comma(context.config, arm, &arm.body));
|
|
}
|
|
}
|
|
// BytePos(1) = closing match brace.
|
|
let last_span = mk_sp(arm_end_pos(&arms[arms.len() - 1]), span.hi - BytePos(1));
|
|
let last_comment = context.snippet(last_span);
|
|
let comment = try_opt!(rewrite_match_arm_comment(context,
|
|
&last_comment,
|
|
width,
|
|
arm_indent,
|
|
&arm_indent_str));
|
|
result.push_str(&comment);
|
|
result.push('\n');
|
|
result.push_str(&context.block_indent.to_string(context.config));
|
|
result.push('}');
|
|
Some(result)
|
|
}
|
|
|
|
fn arm_start_pos(arm: &ast::Arm) -> BytePos {
|
|
let &ast::Arm { ref attrs, ref pats, .. } = arm;
|
|
if !attrs.is_empty() {
|
|
return attrs[0].span.lo;
|
|
}
|
|
|
|
pats[0].span.lo
|
|
}
|
|
|
|
fn arm_end_pos(arm: &ast::Arm) -> BytePos {
|
|
arm.body.span.hi
|
|
}
|
|
|
|
fn arm_comma(config: &Config, arm: &ast::Arm, body: &ast::Expr) -> &'static str {
|
|
if !config.match_wildcard_trailing_comma {
|
|
if arm.pats.len() == 1 && arm.pats[0].node == ast::PatKind::Wild && arm.guard.is_none() {
|
|
return "";
|
|
}
|
|
}
|
|
|
|
if config.match_block_trailing_comma {
|
|
","
|
|
} else if let ast::ExprKind::Block(ref block) = body.node {
|
|
if let ast::BlockCheckMode::Default = block.rules {
|
|
""
|
|
} else {
|
|
","
|
|
}
|
|
} else {
|
|
","
|
|
}
|
|
}
|
|
|
|
// Match arms.
|
|
impl Rewrite for ast::Arm {
|
|
fn rewrite(&self, context: &RewriteContext, width: usize, offset: Indent) -> Option<String> {
|
|
let &ast::Arm { ref attrs, ref pats, ref guard, ref body } = self;
|
|
|
|
// FIXME this is all a bit grotty, would be nice to abstract out the
|
|
// treatment of attributes.
|
|
let attr_str = if !attrs.is_empty() {
|
|
// We only use this visitor for the attributes, should we use it for
|
|
// more?
|
|
let mut attr_visitor = FmtVisitor::from_codemap(context.parse_session, context.config);
|
|
attr_visitor.block_indent = context.block_indent;
|
|
attr_visitor.last_pos = attrs[0].span.lo;
|
|
if attr_visitor.visit_attrs(attrs) {
|
|
// Attributes included a skip instruction.
|
|
return None;
|
|
}
|
|
attr_visitor.format_missing(pats[0].span.lo);
|
|
attr_visitor.buffer.to_string()
|
|
} else {
|
|
String::new()
|
|
};
|
|
|
|
// Patterns
|
|
// 5 = ` => {`
|
|
let pat_budget = try_opt!(width.checked_sub(5));
|
|
let pat_strs = try_opt!(pats.iter()
|
|
.map(|p| p.rewrite(context, pat_budget, offset))
|
|
.collect::<Option<Vec<_>>>());
|
|
|
|
let all_simple = pat_strs.iter().all(|p| pat_is_simple(p));
|
|
let items: Vec<_> = pat_strs.into_iter().map(ListItem::from_str).collect();
|
|
let fmt = ListFormatting {
|
|
tactic: if all_simple {
|
|
DefinitiveListTactic::Mixed
|
|
} else {
|
|
DefinitiveListTactic::Vertical
|
|
},
|
|
separator: " |",
|
|
trailing_separator: SeparatorTactic::Never,
|
|
indent: offset,
|
|
width: pat_budget,
|
|
ends_with_newline: false,
|
|
config: context.config,
|
|
};
|
|
let pats_str = try_opt!(write_list(items, &fmt));
|
|
|
|
let budget = if pats_str.contains('\n') {
|
|
context.config.max_width - offset.width()
|
|
} else {
|
|
width
|
|
};
|
|
|
|
let guard_str = try_opt!(rewrite_guard(context,
|
|
guard,
|
|
budget,
|
|
offset,
|
|
trimmed_last_line_width(&pats_str)));
|
|
|
|
let pats_str = format!("{}{}", pats_str, guard_str);
|
|
// Where the next text can start.
|
|
let mut line_start = last_line_width(&pats_str);
|
|
if !pats_str.contains('\n') {
|
|
line_start += offset.width();
|
|
}
|
|
|
|
let body = match body.node {
|
|
ast::ExprKind::Block(ref block) if !is_unsafe_block(block) &&
|
|
is_simple_block(block, context.codemap) &&
|
|
context.config.wrap_match_arms => {
|
|
if let ast::StmtKind::Expr(ref expr) = block.stmts[0].node {
|
|
expr
|
|
} else {
|
|
&**body
|
|
}
|
|
}
|
|
_ => &**body,
|
|
};
|
|
|
|
let comma = arm_comma(&context.config, self, body);
|
|
let alt_block_sep = String::from("\n") + &context.block_indent.to_string(context.config);
|
|
|
|
// Let's try and get the arm body on the same line as the condition.
|
|
// 4 = ` => `.len()
|
|
if context.config.max_width > line_start + comma.len() + 4 {
|
|
let budget = context.config.max_width - line_start - comma.len() - 4;
|
|
let offset = Indent::new(offset.block_indent, line_start + 4 - offset.block_indent);
|
|
let rewrite = nop_block_collapse(body.rewrite(context, budget, offset), budget);
|
|
let is_block = if let ast::ExprKind::Block(..) = body.node {
|
|
true
|
|
} else {
|
|
false
|
|
};
|
|
|
|
let block_sep = match context.config.control_brace_style {
|
|
ControlBraceStyle::AlwaysNextLine if is_block => alt_block_sep.as_str(),
|
|
_ => " ",
|
|
};
|
|
match rewrite {
|
|
Some(ref body_str) if !body_str.contains('\n') || !context.config.wrap_match_arms ||
|
|
is_block => {
|
|
return Some(format!("{}{} =>{}{}{}",
|
|
attr_str.trim_left(),
|
|
pats_str,
|
|
block_sep,
|
|
body_str,
|
|
comma));
|
|
}
|
|
_ => {}
|
|
}
|
|
}
|
|
|
|
// FIXME: we're doing a second rewrite of the expr; This may not be
|
|
// necessary.
|
|
let body_budget = try_opt!(width.checked_sub(context.config.tab_spaces));
|
|
let indent = context.block_indent.block_indent(context.config);
|
|
let inner_context = &RewriteContext { block_indent: indent, ..*context };
|
|
let next_line_body =
|
|
try_opt!(nop_block_collapse(body.rewrite(inner_context, body_budget, indent),
|
|
body_budget));
|
|
let indent_str = offset.block_indent(context.config).to_string(context.config);
|
|
let (body_prefix, body_suffix) = if context.config.wrap_match_arms {
|
|
if context.config.match_block_trailing_comma {
|
|
(" {", "},")
|
|
} else {
|
|
(" {", "}")
|
|
}
|
|
} else {
|
|
("", "")
|
|
};
|
|
|
|
let block_sep = match context.config.control_brace_style {
|
|
ControlBraceStyle::AlwaysNextLine => alt_block_sep,
|
|
ControlBraceStyle::AlwaysSameLine => String::from(body_prefix) + "\n",
|
|
};
|
|
Some(format!("{}{} =>{}{}{}\n{}{}",
|
|
attr_str.trim_left(),
|
|
pats_str,
|
|
block_sep,
|
|
indent_str,
|
|
next_line_body,
|
|
offset.to_string(context.config),
|
|
body_suffix))
|
|
}
|
|
}
|
|
|
|
// A pattern is simple if it is very short or it is short-ish and just a path.
|
|
// E.g. `Foo::Bar` is simple, but `Foo(..)` is not.
|
|
fn pat_is_simple(pat_str: &str) -> bool {
|
|
pat_str.len() <= 16 ||
|
|
(pat_str.len() <= 24 && pat_str.chars().all(|c| c.is_alphabetic() || c == ':'))
|
|
}
|
|
|
|
// The `if ...` guard on a match arm.
|
|
fn rewrite_guard(context: &RewriteContext,
|
|
guard: &Option<ptr::P<ast::Expr>>,
|
|
width: usize,
|
|
offset: Indent,
|
|
// The amount of space used up on this line for the pattern in
|
|
// the arm (excludes offset).
|
|
pattern_width: usize)
|
|
-> Option<String> {
|
|
if let Some(ref guard) = *guard {
|
|
// First try to fit the guard string on the same line as the pattern.
|
|
// 4 = ` if `, 5 = ` => {`
|
|
let overhead = pattern_width + 4 + 5;
|
|
if overhead < width {
|
|
let cond_str = guard.rewrite(context, width - overhead, offset + pattern_width + 4);
|
|
if let Some(cond_str) = cond_str {
|
|
return Some(format!(" if {}", cond_str));
|
|
}
|
|
}
|
|
|
|
// Not enough space to put the guard after the pattern, try a newline.
|
|
let overhead = offset.block_indent(context.config).width() + 4 + 5;
|
|
if overhead < width {
|
|
let cond_str = guard.rewrite(context,
|
|
width - overhead,
|
|
// 3 == `if `
|
|
offset.block_indent(context.config) + 3);
|
|
if let Some(cond_str) = cond_str {
|
|
return Some(format!("\n{}if {}",
|
|
offset.block_indent(context.config).to_string(context.config),
|
|
cond_str));
|
|
}
|
|
}
|
|
|
|
None
|
|
} else {
|
|
Some(String::new())
|
|
}
|
|
}
|
|
|
|
fn rewrite_pat_expr(context: &RewriteContext,
|
|
pat: Option<&ast::Pat>,
|
|
expr: &ast::Expr,
|
|
matcher: &str,
|
|
// Connecting piece between pattern and expression,
|
|
// *without* trailing space.
|
|
connector: &str,
|
|
width: usize,
|
|
offset: Indent)
|
|
-> Option<String> {
|
|
let pat_offset = offset + matcher.len();
|
|
let mut result = match pat {
|
|
Some(pat) => {
|
|
let pat_budget = try_opt!(width.checked_sub(connector.len() + matcher.len()));
|
|
let pat_string = try_opt!(pat.rewrite(context, pat_budget, pat_offset));
|
|
format!("{}{}{}", matcher, pat_string, connector)
|
|
}
|
|
None => String::new(),
|
|
};
|
|
|
|
// Consider only the last line of the pat string.
|
|
let extra_offset = extra_offset(&result, offset);
|
|
|
|
// The expression may (partionally) fit on the current line.
|
|
if width > extra_offset + 1 {
|
|
let spacer = if pat.is_some() { " " } else { "" };
|
|
|
|
let expr_rewrite = expr.rewrite(context,
|
|
try_opt!(width.checked_sub(extra_offset + spacer.len())),
|
|
offset + extra_offset + spacer.len());
|
|
|
|
if let Some(expr_string) = expr_rewrite {
|
|
let pat_simple =
|
|
pat.and_then(|p| p.rewrite(context, context.config.max_width, Indent::empty()))
|
|
.map(|s| pat_is_simple(&s));
|
|
|
|
if pat.is_none() || pat_simple.unwrap_or(false) || !expr_string.contains('\n') {
|
|
result.push_str(spacer);
|
|
result.push_str(&expr_string);
|
|
return Some(result);
|
|
}
|
|
}
|
|
}
|
|
|
|
let nested = context.nested_context();
|
|
|
|
// The expression won't fit on the current line, jump to next.
|
|
result.push('\n');
|
|
result.push_str(&nested.block_indent.to_string(context.config));
|
|
|
|
let expr_rewrite =
|
|
expr.rewrite(&nested,
|
|
try_opt!(context.config.max_width.checked_sub(nested.block_indent.width())),
|
|
nested.block_indent);
|
|
result.push_str(&try_opt!(expr_rewrite));
|
|
|
|
Some(result)
|
|
}
|
|
|
|
fn rewrite_string_lit(context: &RewriteContext,
|
|
span: Span,
|
|
width: usize,
|
|
offset: Indent)
|
|
-> Option<String> {
|
|
let string_lit = context.snippet(span);
|
|
|
|
if !context.config.format_strings && !context.config.force_format_strings {
|
|
return Some(string_lit);
|
|
}
|
|
|
|
if !context.config.force_format_strings &&
|
|
!string_requires_rewrite(context, span, &string_lit, width, offset) {
|
|
return Some(string_lit);
|
|
}
|
|
|
|
let fmt = StringFormat {
|
|
opener: "\"",
|
|
closer: "\"",
|
|
line_start: " ",
|
|
line_end: "\\",
|
|
width: width,
|
|
offset: offset,
|
|
trim_end: false,
|
|
config: context.config,
|
|
};
|
|
|
|
// Remove the quote characters.
|
|
let str_lit = &string_lit[1..string_lit.len() - 1];
|
|
|
|
rewrite_string(str_lit, &fmt)
|
|
}
|
|
|
|
fn string_requires_rewrite(context: &RewriteContext,
|
|
span: Span,
|
|
string: &str,
|
|
width: usize,
|
|
offset: Indent)
|
|
-> bool {
|
|
if context.codemap.lookup_char_pos(span.lo).col.0 != offset.width() {
|
|
return true;
|
|
}
|
|
|
|
for (i, line) in string.lines().enumerate() {
|
|
if i == 0 {
|
|
if line.len() > width {
|
|
return true;
|
|
}
|
|
} else {
|
|
if line.len() > width + offset.width() {
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
false
|
|
}
|
|
|
|
pub fn rewrite_call<R>(context: &RewriteContext,
|
|
callee: &R,
|
|
args: &[ptr::P<ast::Expr>],
|
|
span: Span,
|
|
width: usize,
|
|
offset: Indent)
|
|
-> Option<String>
|
|
where R: Rewrite
|
|
{
|
|
let closure = |callee_max_width| {
|
|
rewrite_call_inner(context, callee, callee_max_width, args, span, width, offset)
|
|
};
|
|
|
|
// 2 is for parens
|
|
let max_width = try_opt!(width.checked_sub(2));
|
|
binary_search(1, max_width, closure)
|
|
}
|
|
|
|
fn rewrite_call_inner<R>(context: &RewriteContext,
|
|
callee: &R,
|
|
max_callee_width: usize,
|
|
args: &[ptr::P<ast::Expr>],
|
|
span: Span,
|
|
width: usize,
|
|
offset: Indent)
|
|
-> Result<String, Ordering>
|
|
where R: Rewrite
|
|
{
|
|
let callee = callee.borrow();
|
|
// FIXME using byte lens instead of char lens (and probably all over the
|
|
// place too)
|
|
let callee_str = match callee.rewrite(context, max_callee_width, offset) {
|
|
Some(string) => {
|
|
if !string.contains('\n') && string.len() > max_callee_width {
|
|
panic!("{:?} {}", string, max_callee_width);
|
|
} else {
|
|
string
|
|
}
|
|
}
|
|
None => return Err(Ordering::Greater),
|
|
};
|
|
|
|
let span_lo = context.codemap.span_after(span, "(");
|
|
let span = mk_sp(span_lo, span.hi);
|
|
|
|
let extra_offset = extra_offset(&callee_str, offset);
|
|
// 2 is for parens.
|
|
let remaining_width = match width.checked_sub(extra_offset + 2) {
|
|
Some(str) => str,
|
|
None => return Err(Ordering::Greater),
|
|
};
|
|
let offset = offset + extra_offset + 1;
|
|
let arg_count = args.len();
|
|
let block_indent = if arg_count == 1 {
|
|
context.block_indent
|
|
} else {
|
|
offset
|
|
};
|
|
let inner_context = &RewriteContext { block_indent: block_indent, ..*context };
|
|
|
|
let items = itemize_list(context.codemap,
|
|
args.iter(),
|
|
")",
|
|
|item| item.span.lo,
|
|
|item| item.span.hi,
|
|
|item| item.rewrite(inner_context, remaining_width, offset),
|
|
span.lo,
|
|
span.hi);
|
|
let mut item_vec: Vec<_> = items.collect();
|
|
|
|
// Try letting the last argument overflow to the next line with block
|
|
// indentation. If its first line fits on one line with the other arguments,
|
|
// we format the function arguments horizontally.
|
|
let overflow_last = match args.last().map(|x| &x.node) {
|
|
Some(&ast::ExprKind::Closure(..)) |
|
|
Some(&ast::ExprKind::Block(..)) if arg_count > 1 => true,
|
|
_ => false,
|
|
} && context.config.chains_overflow_last;
|
|
|
|
let mut orig_last = None;
|
|
let mut placeholder = None;
|
|
|
|
// Replace the last item with its first line to see if it fits with
|
|
// first arguments.
|
|
if overflow_last {
|
|
let inner_context = &RewriteContext { block_indent: context.block_indent, ..*context };
|
|
let rewrite = args.last().unwrap().rewrite(inner_context, remaining_width, offset);
|
|
|
|
if let Some(rewrite) = rewrite {
|
|
let rewrite_first_line = Some(rewrite[..first_line_width(&rewrite)].to_owned());
|
|
placeholder = Some(rewrite);
|
|
|
|
swap(&mut item_vec[arg_count - 1].item, &mut orig_last);
|
|
item_vec[arg_count - 1].item = rewrite_first_line;
|
|
}
|
|
}
|
|
|
|
let tactic = definitive_tactic(&item_vec,
|
|
ListTactic::LimitedHorizontalVertical(context.config
|
|
.fn_call_width),
|
|
remaining_width);
|
|
|
|
// Replace the stub with the full overflowing last argument if the rewrite
|
|
// succeeded and its first line fits with the other arguments.
|
|
match (overflow_last, tactic, placeholder) {
|
|
(true, DefinitiveListTactic::Horizontal, placeholder @ Some(..)) => {
|
|
item_vec[arg_count - 1].item = placeholder;
|
|
}
|
|
(true, _, _) => {
|
|
item_vec[arg_count - 1].item = orig_last;
|
|
}
|
|
(false, _, _) => {}
|
|
}
|
|
|
|
let fmt = ListFormatting {
|
|
tactic: tactic,
|
|
separator: ",",
|
|
trailing_separator: SeparatorTactic::Never,
|
|
indent: offset,
|
|
width: width,
|
|
ends_with_newline: false,
|
|
config: context.config,
|
|
};
|
|
|
|
let list_str = match write_list(&item_vec, &fmt) {
|
|
Some(str) => str,
|
|
None => return Err(Ordering::Less),
|
|
};
|
|
|
|
Ok(if context.config.spaces_within_parens && list_str.len() > 0 {
|
|
format!("{}( {} )", callee_str, list_str)
|
|
} else {
|
|
format!("{}({})", callee_str, list_str)
|
|
})
|
|
}
|
|
|
|
fn rewrite_paren(context: &RewriteContext,
|
|
subexpr: &ast::Expr,
|
|
width: usize,
|
|
offset: Indent)
|
|
-> Option<String> {
|
|
debug!("rewrite_paren, width: {}, offset: {:?}", width, offset);
|
|
// 1 is for opening paren, 2 is for opening+closing, we want to keep the closing
|
|
// paren on the same line as the subexpr.
|
|
let subexpr_str = subexpr.rewrite(context, try_opt!(width.checked_sub(2)), offset + 1);
|
|
debug!("rewrite_paren, subexpr_str: `{:?}`", subexpr_str);
|
|
|
|
subexpr_str.map(|s| if context.config.spaces_within_parens && s.len() > 0 {
|
|
format!("( {} )", s)
|
|
} else {
|
|
format!("({})", s)
|
|
})
|
|
}
|
|
|
|
fn rewrite_struct_lit<'a>(context: &RewriteContext,
|
|
path: &ast::Path,
|
|
fields: &'a [ast::Field],
|
|
base: Option<&'a ast::Expr>,
|
|
span: Span,
|
|
width: usize,
|
|
offset: Indent)
|
|
-> Option<String> {
|
|
debug!("rewrite_struct_lit: width {}, offset {:?}", width, offset);
|
|
|
|
enum StructLitField<'a> {
|
|
Regular(&'a ast::Field),
|
|
Base(&'a ast::Expr),
|
|
}
|
|
|
|
// 2 = " {".len()
|
|
let path_budget = try_opt!(width.checked_sub(2));
|
|
let path_str = try_opt!(rewrite_path(context, true, None, path, path_budget, offset));
|
|
|
|
// Foo { a: Foo } - indent is +3, width is -5.
|
|
let h_budget = width.checked_sub(path_str.len() + 5).unwrap_or(0);
|
|
// The 1 taken from the v_budget is for the comma.
|
|
let (indent, v_budget) = match context.config.struct_lit_style {
|
|
StructLitStyle::Visual => (offset + path_str.len() + 3, h_budget),
|
|
StructLitStyle::Block => {
|
|
// If we are all on one line, then we'll ignore the indent, and we
|
|
// have a smaller budget.
|
|
let indent = context.block_indent.block_indent(context.config);
|
|
let v_budget = context.config.max_width.checked_sub(indent.width()).unwrap_or(0);
|
|
(indent, v_budget)
|
|
}
|
|
};
|
|
|
|
let field_iter = fields.into_iter()
|
|
.map(StructLitField::Regular)
|
|
.chain(base.into_iter().map(StructLitField::Base));
|
|
|
|
let inner_context = &RewriteContext { block_indent: indent, ..*context };
|
|
|
|
let items = itemize_list(context.codemap,
|
|
field_iter,
|
|
"}",
|
|
|item| {
|
|
match *item {
|
|
StructLitField::Regular(field) => field.span.lo,
|
|
StructLitField::Base(expr) => {
|
|
let last_field_hi = fields.last().map_or(span.lo, |field| field.span.hi);
|
|
let snippet = context.snippet(mk_sp(last_field_hi, expr.span.lo));
|
|
let pos = snippet.find_uncommented("..").unwrap();
|
|
last_field_hi + BytePos(pos as u32)
|
|
}
|
|
}
|
|
},
|
|
|item| {
|
|
match *item {
|
|
StructLitField::Regular(field) => field.span.hi,
|
|
StructLitField::Base(expr) => expr.span.hi,
|
|
}
|
|
},
|
|
|item| {
|
|
match *item {
|
|
StructLitField::Regular(field) => {
|
|
rewrite_field(inner_context,
|
|
field,
|
|
v_budget.checked_sub(1).unwrap_or(0),
|
|
indent)
|
|
}
|
|
StructLitField::Base(expr) => {
|
|
// 2 = ..
|
|
expr.rewrite(inner_context, try_opt!(v_budget.checked_sub(2)), indent + 2)
|
|
.map(|s| format!("..{}", s))
|
|
}
|
|
}
|
|
},
|
|
context.codemap.span_after(span, "{"),
|
|
span.hi);
|
|
let item_vec = items.collect::<Vec<_>>();
|
|
|
|
let tactic = {
|
|
let mut prelim_tactic = match (context.config.struct_lit_style, fields.len()) {
|
|
(StructLitStyle::Visual, 1) => ListTactic::HorizontalVertical,
|
|
_ => context.config.struct_lit_multiline_style.to_list_tactic(),
|
|
};
|
|
|
|
if prelim_tactic == ListTactic::HorizontalVertical && fields.len() > 1 {
|
|
prelim_tactic = ListTactic::LimitedHorizontalVertical(context.config.struct_lit_width);
|
|
}
|
|
|
|
definitive_tactic(&item_vec, prelim_tactic, h_budget)
|
|
};
|
|
|
|
let budget = match tactic {
|
|
DefinitiveListTactic::Horizontal => h_budget,
|
|
_ => v_budget,
|
|
};
|
|
|
|
let ends_with_newline = context.config.struct_lit_style != StructLitStyle::Visual &&
|
|
tactic == DefinitiveListTactic::Vertical;
|
|
|
|
let fmt = ListFormatting {
|
|
tactic: tactic,
|
|
separator: ",",
|
|
trailing_separator: if base.is_some() {
|
|
SeparatorTactic::Never
|
|
} else {
|
|
context.config.struct_lit_trailing_comma
|
|
},
|
|
indent: indent,
|
|
width: budget,
|
|
ends_with_newline: ends_with_newline,
|
|
config: context.config,
|
|
};
|
|
let fields_str = try_opt!(write_list(&item_vec, &fmt));
|
|
|
|
if fields_str.is_empty() {
|
|
return Some(format!("{} {{}}", path_str));
|
|
}
|
|
|
|
let format_on_newline = || {
|
|
let inner_indent = context.block_indent
|
|
.block_indent(context.config)
|
|
.to_string(context.config);
|
|
let outer_indent = context.block_indent.to_string(context.config);
|
|
Some(format!("{} {{\n{}{}\n{}}}",
|
|
path_str,
|
|
inner_indent,
|
|
fields_str,
|
|
outer_indent))
|
|
};
|
|
|
|
match (context.config.struct_lit_style, context.config.struct_lit_multiline_style) {
|
|
(StructLitStyle::Block, _) if fields_str.contains('\n') || fields_str.len() > h_budget => {
|
|
format_on_newline()
|
|
}
|
|
(StructLitStyle::Block, MultilineStyle::ForceMulti) => format_on_newline(),
|
|
_ => Some(format!("{} {{ {} }}", path_str, fields_str)),
|
|
}
|
|
|
|
// FIXME if context.config.struct_lit_style == Visual, but we run out
|
|
// of space, we should fall back to BlockIndent.
|
|
}
|
|
|
|
pub fn type_annotation_separator(config: &Config) -> &str {
|
|
match (config.space_before_type_annotation, config.space_after_type_annotation_colon) {
|
|
(true, true) => " : ",
|
|
(true, false) => " :",
|
|
(false, true) => ": ",
|
|
(false, false) => ":",
|
|
}
|
|
}
|
|
|
|
fn rewrite_field(context: &RewriteContext,
|
|
field: &ast::Field,
|
|
width: usize,
|
|
offset: Indent)
|
|
-> Option<String> {
|
|
let name = &field.ident.node.to_string();
|
|
let separator = type_annotation_separator(context.config);
|
|
let overhead = name.len() + separator.len();
|
|
let expr = field.expr.rewrite(context,
|
|
try_opt!(width.checked_sub(overhead)),
|
|
offset + overhead);
|
|
|
|
match expr {
|
|
Some(e) => Some(format!("{}{}{}", name, separator, e)),
|
|
None => {
|
|
let expr_offset = offset.block_indent(context.config);
|
|
let expr = field.expr.rewrite(context,
|
|
try_opt!(context.config
|
|
.max_width
|
|
.checked_sub(expr_offset.width())),
|
|
expr_offset);
|
|
expr.map(|s| format!("{}:\n{}{}", name, expr_offset.to_string(&context.config), s))
|
|
}
|
|
}
|
|
}
|
|
|
|
pub fn rewrite_tuple<'a, I>(context: &RewriteContext,
|
|
mut items: I,
|
|
span: Span,
|
|
width: usize,
|
|
offset: Indent)
|
|
-> Option<String>
|
|
where I: ExactSizeIterator,
|
|
<I as Iterator>::Item: Deref,
|
|
<I::Item as Deref>::Target: Rewrite + Spanned + 'a
|
|
{
|
|
let indent = offset + 1;
|
|
let aligned = RewriteContext { block_indent: indent, ..context.clone() };
|
|
|
|
// In case of length 1, need a trailing comma
|
|
if items.len() == 1 {
|
|
// 3 = "(" + ",)"
|
|
let budget = try_opt!(width.checked_sub(3));
|
|
return items.next()
|
|
.unwrap()
|
|
.rewrite(&aligned, budget, indent)
|
|
.map(|s| if context.config.spaces_within_parens {
|
|
format!("( {}, )", s)
|
|
} else {
|
|
format!("({},)", s)
|
|
});
|
|
}
|
|
|
|
let list_lo = context.codemap.span_after(span, "(");
|
|
let budget = try_opt!(width.checked_sub(2));
|
|
let items = itemize_list(context.codemap,
|
|
items,
|
|
")",
|
|
|item| item.span().lo,
|
|
|item| item.span().hi,
|
|
|item| item.rewrite(&aligned, budget, indent),
|
|
list_lo,
|
|
span.hi - BytePos(1));
|
|
let list_str = try_opt!(format_item_list(items, budget, indent, context.config));
|
|
|
|
if context.config.spaces_within_parens && list_str.len() > 0 {
|
|
Some(format!("( {} )", list_str))
|
|
} else {
|
|
Some(format!("({})", list_str))
|
|
}
|
|
}
|
|
|
|
fn rewrite_binary_op(context: &RewriteContext,
|
|
op: &ast::BinOp,
|
|
lhs: &ast::Expr,
|
|
rhs: &ast::Expr,
|
|
width: usize,
|
|
offset: Indent)
|
|
-> Option<String> {
|
|
// FIXME: format comments between operands and operator
|
|
|
|
let operator_str = context.snippet(op.span);
|
|
|
|
// 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.
|
|
let rhs_result = try_opt!(rhs.rewrite(context, width, offset));
|
|
|
|
// Second condition is needed in case of line break not caused by a
|
|
// shortage of space, but by end-of-line comments, for example.
|
|
// Note that this is non-conservative, but its just to see if it's even
|
|
// worth trying to put everything on one line.
|
|
if rhs_result.len() + 2 + operator_str.len() < width && !rhs_result.contains('\n') {
|
|
// 1 = space between lhs expr and operator
|
|
if let Some(mut result) = lhs.rewrite(context, width - 1 - operator_str.len(), offset) {
|
|
result.push(' ');
|
|
result.push_str(&operator_str);
|
|
result.push(' ');
|
|
|
|
let remaining_width = width.checked_sub(last_line_width(&result)).unwrap_or(0);
|
|
|
|
if rhs_result.len() <= remaining_width {
|
|
result.push_str(&rhs_result);
|
|
return Some(result);
|
|
}
|
|
|
|
if let Some(rhs_result) = rhs.rewrite(context, remaining_width, offset + result.len()) {
|
|
if rhs_result.len() <= remaining_width {
|
|
result.push_str(&rhs_result);
|
|
return Some(result);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// We have to use multiple lines.
|
|
|
|
// Re-evaluate the lhs because we have more space now:
|
|
let budget = try_opt!(context.config
|
|
.max_width
|
|
.checked_sub(offset.width() + 1 + operator_str.len()));
|
|
Some(format!("{} {}\n{}{}",
|
|
try_opt!(lhs.rewrite(context, budget, offset)),
|
|
operator_str,
|
|
offset.to_string(context.config),
|
|
rhs_result))
|
|
}
|
|
|
|
pub fn rewrite_unary_prefix<R: Rewrite>(context: &RewriteContext,
|
|
prefix: &str,
|
|
rewrite: &R,
|
|
width: usize,
|
|
offset: Indent)
|
|
-> Option<String> {
|
|
rewrite.rewrite(context,
|
|
try_opt!(width.checked_sub(prefix.len())),
|
|
offset + prefix.len())
|
|
.map(|r| format!("{}{}", prefix, r))
|
|
}
|
|
|
|
// FIXME: this is probably not correct for multi-line Rewrites. we should
|
|
// subtract suffix.len() from the last line budget, not the first!
|
|
pub fn rewrite_unary_suffix<R: Rewrite>(context: &RewriteContext,
|
|
suffix: &str,
|
|
rewrite: &R,
|
|
width: usize,
|
|
offset: Indent)
|
|
-> Option<String> {
|
|
rewrite.rewrite(context, try_opt!(width.checked_sub(suffix.len())), offset)
|
|
.map(|mut r| {
|
|
r.push_str(suffix);
|
|
r
|
|
})
|
|
}
|
|
|
|
fn rewrite_unary_op(context: &RewriteContext,
|
|
op: &ast::UnOp,
|
|
expr: &ast::Expr,
|
|
width: usize,
|
|
offset: Indent)
|
|
-> Option<String> {
|
|
// For some reason, an UnOp is not spanned like BinOp!
|
|
let operator_str = match *op {
|
|
ast::UnOp::Deref => "*",
|
|
ast::UnOp::Not => "!",
|
|
ast::UnOp::Neg => "-",
|
|
};
|
|
rewrite_unary_prefix(context, operator_str, expr, width, offset)
|
|
}
|
|
|
|
fn rewrite_assignment(context: &RewriteContext,
|
|
lhs: &ast::Expr,
|
|
rhs: &ast::Expr,
|
|
op: Option<&ast::BinOp>,
|
|
width: usize,
|
|
offset: Indent)
|
|
-> Option<String> {
|
|
let operator_str = match op {
|
|
Some(op) => context.snippet(op.span),
|
|
None => "=".to_owned(),
|
|
};
|
|
|
|
// 1 = space between lhs and operator.
|
|
let max_width = try_opt!(width.checked_sub(operator_str.len() + 1));
|
|
let lhs_str = format!("{} {}",
|
|
try_opt!(lhs.rewrite(context, max_width, offset)),
|
|
operator_str);
|
|
|
|
rewrite_assign_rhs(context, lhs_str, rhs, width, offset)
|
|
}
|
|
|
|
// The left hand side must contain everything up to, and including, the
|
|
// assignment operator.
|
|
pub fn rewrite_assign_rhs<S: Into<String>>(context: &RewriteContext,
|
|
lhs: S,
|
|
ex: &ast::Expr,
|
|
width: usize,
|
|
offset: Indent)
|
|
-> Option<String> {
|
|
let mut result = lhs.into();
|
|
let last_line_width = last_line_width(&result) -
|
|
if result.contains('\n') {
|
|
offset.width()
|
|
} else {
|
|
0
|
|
};
|
|
// 1 = space between operator and rhs.
|
|
let max_width = try_opt!(width.checked_sub(last_line_width + 1));
|
|
let rhs = ex.rewrite(context, max_width, offset + last_line_width + 1);
|
|
|
|
fn count_line_breaks(src: &str) -> usize {
|
|
src.chars().filter(|&x| x == '\n').count()
|
|
}
|
|
|
|
match rhs {
|
|
Some(ref new_str) if count_line_breaks(new_str) < 2 => {
|
|
result.push(' ');
|
|
result.push_str(new_str);
|
|
}
|
|
_ => {
|
|
// Expression did not fit on the same line as the identifier or is
|
|
// at least three lines big. Try splitting the line and see
|
|
// if that works better.
|
|
let new_offset = offset.block_indent(context.config);
|
|
let max_width = try_opt!((width + offset.width()).checked_sub(new_offset.width()));
|
|
let inner_context = context.nested_context();
|
|
let new_rhs = ex.rewrite(&inner_context, max_width, new_offset);
|
|
|
|
// FIXME: DRY!
|
|
match (rhs, new_rhs) {
|
|
(Some(ref orig_rhs), Some(ref replacement_rhs))
|
|
if count_line_breaks(orig_rhs) >
|
|
count_line_breaks(replacement_rhs) + 1 => {
|
|
result.push_str(&format!("\n{}", new_offset.to_string(context.config)));
|
|
result.push_str(replacement_rhs);
|
|
}
|
|
(None, Some(ref final_rhs)) => {
|
|
result.push_str(&format!("\n{}", new_offset.to_string(context.config)));
|
|
result.push_str(final_rhs);
|
|
}
|
|
(None, None) => return None,
|
|
(Some(ref orig_rhs), _) => {
|
|
result.push(' ');
|
|
result.push_str(orig_rhs);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
Some(result)
|
|
}
|
|
|
|
fn rewrite_expr_addrof(context: &RewriteContext,
|
|
mutability: ast::Mutability,
|
|
expr: &ast::Expr,
|
|
width: usize,
|
|
offset: Indent)
|
|
-> Option<String> {
|
|
let operator_str = match mutability {
|
|
ast::Mutability::Immutable => "&",
|
|
ast::Mutability::Mutable => "&mut ",
|
|
};
|
|
rewrite_unary_prefix(context, operator_str, expr, width, offset)
|
|
}
|