1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // A generic trait to abstract the rewriting of an element (of the AST).
13 use syntax::codemap::{CodeMap, Span};
18 /// Rewrite self into offset and width.
19 /// `offset` is the indentation of the first line. The next lines
20 /// should begin with a least `offset` spaces (except backwards
21 /// indentation). The first line should not begin with indentation.
22 /// `width` is the maximum number of characters on the last line
23 /// (excluding offset). The width of other lines is not limited by
25 fn rewrite(&self, context: &RewriteContext, width: usize, offset: usize) -> Option<String>;
28 pub struct RewriteContext<'a> {
29 pub codemap: &'a CodeMap,
30 pub config: &'a Config,
32 // Indentation due to nesting of blocks.
33 pub block_indent: usize,
34 // *Extra* indentation due to overflowing to the next line, e.g.,
37 // The extra 4 spaces when formatting `bar()` is overflow_indent.
38 pub overflow_indent: usize,
41 impl<'a> RewriteContext<'a> {
42 pub fn nested_context(&self) -> RewriteContext<'a> {
44 codemap: self.codemap,
46 block_indent: self.block_indent + self.config.tab_spaces,
47 overflow_indent: self.overflow_indent,
51 pub fn overflow_context(&self, overflow: usize) -> RewriteContext<'a> {
53 codemap: self.codemap,
55 block_indent: self.block_indent,
56 overflow_indent: overflow,
60 pub fn snippet(&self, span: Span) -> String {
61 self.codemap.span_to_snippet(span).unwrap()