rust/src/rustdoc/unindent_pass.rs
2012-09-18 16:48:58 -07:00

120 lines
3.3 KiB
Rust

/*!
* Removes the common level of indention from description strings. For
* instance, if an entire doc comment is indented 8 spaces we want to
* remove those 8 spaces from every line.
*
* The first line of a string is allowed to be intend less than
* subsequent lines in the same paragraph in order to account for
* instances where the string containing the doc comment is opened in the
* middle of a line, and each of the following lines is indented.
*/
export mk_pass;
fn mk_pass() -> Pass {
text_pass::mk_pass(~"unindent", unindent)
}
fn unindent(s: ~str) -> ~str {
let lines = str::lines_any(s);
let mut saw_first_line = false;
let mut saw_second_line = false;
let min_indent = do vec::foldl(uint::max_value, lines)
|min_indent, line| {
// After we see the first non-whitespace line, look at
// the line we have. If it is not whitespace, and therefore
// part of the first paragraph, then ignore the indentation
// level of the first line
let ignore_previous_indents =
saw_first_line &&
!saw_second_line &&
!str::is_whitespace(line);
let min_indent = if ignore_previous_indents {
uint::max_value
} else {
min_indent
};
if saw_first_line {
saw_second_line = true;
}
if str::is_whitespace(line) {
min_indent
} else {
saw_first_line = true;
let mut spaces = 0;
do str::all(line) |char| {
// Only comparing against space because I wouldn't
// know what to do with mixed whitespace chars
if char == ' ' {
spaces += 1;
true
} else {
false
}
};
uint::min(min_indent, spaces)
}
};
if vec::is_not_empty(lines) {
let unindented = ~[str::trim(vec::head(lines))]
+ do par::map(vec::tail(lines)) |line| {
if str::is_whitespace(line) {
line
} else {
assert str::len(line) >= min_indent;
str::slice(line, min_indent, str::len(line))
}
};
str::connect(unindented, ~"\n")
} else {
s
}
}
#[test]
fn should_unindent() {
let s = ~" line1\n line2";
let r = unindent(s);
assert r == ~"line1\nline2";
}
#[test]
fn should_unindent_multiple_paragraphs() {
let s = ~" line1\n\n line2";
let r = unindent(s);
assert r == ~"line1\n\nline2";
}
#[test]
fn should_leave_multiple_indent_levels() {
// Line 2 is indented another level beyond the
// base indentation and should be preserved
let s = ~" line1\n\n line2";
let r = unindent(s);
assert r == ~"line1\n\n line2";
}
#[test]
fn should_ignore_first_line_indent() {
// Thi first line of the first paragraph may not be indented as
// far due to the way the doc string was written:
//
// #[doc = "Start way over here
// and continue here"]
let s = ~"line1\n line2";
let r = unindent(s);
assert r == ~"line1\nline2";
}
#[test]
fn should_not_ignore_first_line_indent_in_a_single_line_para() {
let s = ~"line1\n\n line2";
let r = unindent(s);
assert r == ~"line1\n\n line2";
}