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};
19 /// Rewrite self into offset and width.
20 /// `offset` is the indentation of the first line. The next lines
21 /// should begin with a least `offset` spaces (except backwards
22 /// indentation). The first line should not begin with indentation.
23 /// `width` is the maximum number of characters on the last line
24 /// (excluding offset). The width of other lines is not limited by
26 fn rewrite(&self, context: &RewriteContext, width: usize, offset: Indent) -> Option<String>;
29 pub struct RewriteContext<'a> {
30 pub codemap: &'a CodeMap,
31 pub config: &'a Config,
33 // Indentation due to nesting of blocks.
34 pub block_indent: Indent,
35 // *Extra* indentation due to overflowing to the next line, e.g.,
38 // The extra 4 spaces when formatting `bar()` is overflow_indent.
39 pub overflow_indent: Indent,
42 impl<'a> RewriteContext<'a> {
43 pub fn nested_context(&self) -> RewriteContext<'a> {
45 codemap: self.codemap,
47 block_indent: self.block_indent.block_indent(self.config.tab_spaces),
48 overflow_indent: self.overflow_indent,
52 pub fn overflow_context(&self, overflow: Indent) -> RewriteContext<'a> {
54 codemap: self.codemap,
56 block_indent: self.block_indent,
57 overflow_indent: overflow,
61 pub fn snippet(&self, span: Span) -> String {
62 self.codemap.span_to_snippet(span).unwrap()