Format tuple like structs

src/comment.rs

@@ -0,0 +1,202 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Format comments.
+
+use string::{StringFormat, rewrite_string};
+use utils::make_indent;
+
+pub fn rewrite_comment(orig: &str, block_style: bool, width: usize, offset: usize) -> String {
+    let s = orig.trim();
+
+    // Edge case: block comments. Let's not trim their lines (for now).
+    let opener = if block_style { "/* " } else { "// " };
+    let closer = if block_style { " */" } else { "" };
+    let line_start = if block_style { " * " } else { "// " };
+
+    let max_chars = width.checked_sub(closer.len()).unwrap_or(1)
+                         .checked_sub(opener.len()).unwrap_or(1);
+
+    let fmt = StringFormat {
+        opener: "",
+        closer: "",
+        line_start: line_start,
+        line_end: "",
+        width: max_chars,
+        offset: offset + opener.len() - line_start.len(),
+        trim_end: true
+    };
+
+    let indent_str = make_indent(offset);
+    let line_breaks = s.chars().filter(|&c| c == '\n').count();
+
+    let (_, mut s) = s.lines().enumerate()
+        .map(|(i, mut line)| {
+            line = line.trim();
+
+            // Drop old closer.
+            if i == line_breaks && line.ends_with("*/") && !line.starts_with("//") {
+                line = &line[..(line.len() - 2)];
+            }
+
+            line.trim_right_matches(' ')
+        })
+        .map(left_trim_comment_line)
+        .fold((true, opener.to_owned()), |(first, mut acc), line| {
+            if !first {
+                acc.push('\n');
+                acc.push_str(&indent_str);
+                acc.push_str(line_start);
+            }
+
+            if line.len() > max_chars {
+                acc.push_str(&rewrite_string(line, &fmt));
+            } else {
+                acc.push_str(line);
+            }
+
+            (false, acc)
+        });
+
+    s.push_str(closer);
+
+    s
+}
+
+fn left_trim_comment_line<'a>(line: &'a str) -> &'a str {
+    if line.starts_with("/* ") || line.starts_with("// ") {
+        &line[3..]
+    } else if line.starts_with("/*") || line.starts_with("* ") || line.starts_with("//") {
+        &line[2..]
+    } else if line.starts_with("*") {
+        &line[1..]
+    } else {
+        line
+    }
+}
+
+#[test]
+fn format_comments() {
+    assert_eq!("/* test */", rewrite_comment(" //test", true, 100, 100));
+    assert_eq!("// comment\n// on a", rewrite_comment("// comment on a", false, 10, 0));
+
+    assert_eq!("//  A multi line comment\n            // between args.",
+               rewrite_comment("//  A multi line comment\n             // between args.",
+                               false,
+                               60,
+                               12));
+
+    let input = "// comment";
+    let expected_output = "/* com\n                                                                      \
+                            * men\n                                                                      \
+                            * t */";
+    assert_eq!(expected_output, rewrite_comment(input, true, 9, 69));
+}
+
+
+pub trait FindUncommented {
+    fn find_uncommented(&self, pat: &str) -> Option<usize>;
+}
+
+impl FindUncommented for str {
+    fn find_uncommented(&self, pat: &str) -> Option<usize> {
+        let mut needle_iter = pat.chars();
+        let mut possible_comment = false;
+
+        for (i, b) in self.char_indices() {
+            match needle_iter.next() {
+                Some(c) => {
+                    if b != c {
+                        needle_iter = pat.chars();
+                    }
+                },
+                None => return Some(i - pat.len())
+            }
+
+            if possible_comment && (b == '/' || b == '*') {
+                return find_comment_end(&self[(i-1)..])
+                    .and_then(|end| {
+                        self[(end + i - 1)..].find_uncommented(pat)
+                                             .map(|idx| idx + end + i - 1)
+                    });
+            }
+
+            possible_comment = b == '/';
+        }
+
+        // Handle case where the pattern is a suffix of the search string
+        match needle_iter.next() {
+            Some(_) => None,
+            None => Some(self.len() - pat.len())
+        }
+    }
+}
+
+#[test]
+fn test_find_uncommented() {
+    fn check(haystack: &str, needle: &str, expected: Option<usize>) {
+        println!("haystack {:?}, needle: {:?}", haystack, needle);
+        assert_eq!(expected, haystack.find_uncommented(needle));
+    }
+
+    check("/*/ */test", "test", Some(6));
+    check("//test\ntest", "test", Some(7));
+    check("/* comment only */", "whatever", None);
+    check("/* comment */ some text /* more commentary */ result", "result", Some(46));
+    check("sup // sup", "p", Some(2));
+    check("sup", "x", None);
+    check("π? /**/ π is nice!", "π is nice", Some(9));
+    check("/*sup yo? \n sup*/ sup", "p", Some(20));
+    check("hel/*lohello*/lo", "hello", None);
+    check("acb", "ab", None);
+}
+
+// Returns the first byte position after the first comment. The given string
+// is expected to be prefixed by a comment, including delimiters.
+// Good: "/* /* inner */ outer */ code();"
+// Bad:  "code(); // hello\n world!"
+pub fn find_comment_end(s: &str) -> Option<usize> {
+    if s.starts_with("//") {
+        s.find('\n').map(|idx| idx + 1)
+    } else {
+        // Block comment
+        let mut levels = 0;
+        let mut prev_char = 'a';
+
+        for (i, mut c) in s.char_indices() {
+            if c == '*' && prev_char == '/' {
+                levels += 1;
+                c = 'a'; // Invalidate prev_char
+            } else if c == '/' && prev_char == '*' {
+                levels -= 1;
+
+                if levels == 0 {
+                    return Some(i + 1);
+                }
+                c = 'a';
+            }
+
+            prev_char = c;
+        }
+
+        None
+    }
+}
+
+#[test]
+fn comment_end() {
+    assert_eq!(Some(6), find_comment_end("// hi\n"));
+    assert_eq!(Some(9), find_comment_end("/* sup */ "));
+    assert_eq!(Some(9), find_comment_end("/*/**/ */ "));
+    assert_eq!(Some(6), find_comment_end("/*/ */ weird!"));
+    assert_eq!(None, find_comment_end("/* hi /* test */"));
+    assert_eq!(None, find_comment_end("// hi /* test */"));
+    assert_eq!(Some(9), find_comment_end("// hi /*\n."));
+}

src/config.rs

@@ -24,7 +24,7 @@ pub struct Config {
     pub fn_brace_style: BraceStyle,
     pub fn_return_indent: ReturnIndent,
     pub fn_args_paren_newline: bool,
-    pub struct_trailing_comma: bool,
+    pub struct_trailing_comma: SeparatorTactic,
     pub struct_lit_trailing_comma: SeparatorTactic,
     pub enum_trailing_comma: bool,
     pub report_todo: ReportTactic,

src/default.toml

@@ -6,7 +6,7 @@ newline_style = "Unix"
 fn_brace_style = "SameLineWhere"
 fn_return_indent = "WithArgs"
 fn_args_paren_newline = true
-struct_trailing_comma = true
+struct_trailing_comma = "Vertical"
 struct_lit_trailing_comma = "Vertical"
 enum_trailing_comma = true
 report_todo = "Always"