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Diffstat (limited to 'textwrap/src/indentation.rs')
| -rw-r--r-- | textwrap/src/indentation.rs | 294 |
1 files changed, 0 insertions, 294 deletions
diff --git a/textwrap/src/indentation.rs b/textwrap/src/indentation.rs deleted file mode 100644 index 276ba10..0000000 --- a/textwrap/src/indentation.rs +++ /dev/null @@ -1,294 +0,0 @@ -//! Functions related to adding and removing indentation from lines of -//! text. -//! -//! The functions here can be used to uniformly indent or dedent -//! (unindent) word wrapped lines of text. - -/// Add prefix to each non-empty line. -/// -/// ``` -/// use textwrap::indent; -/// -/// assert_eq!(indent(" -/// Foo -/// Bar -/// ", " "), " -/// Foo -/// Bar -/// "); -/// ``` -/// -/// Empty lines (lines consisting only of whitespace) are not indented -/// and the whitespace is replaced by a single newline (`\n`): -/// -/// ``` -/// use textwrap::indent; -/// -/// assert_eq!(indent(" -/// Foo -/// -/// Bar -/// \t -/// Baz -/// ", "->"), " -/// ->Foo -/// -/// ->Bar -/// -/// ->Baz -/// "); -/// ``` -/// -/// Leading and trailing whitespace on non-empty lines is kept -/// unchanged: -/// -/// ``` -/// use textwrap::indent; -/// -/// assert_eq!(indent(" \t Foo ", "->"), "-> \t Foo \n"); -/// ``` -pub fn indent(s: &str, prefix: &str) -> String { - let mut result = String::new(); - for line in s.lines() { - if line.chars().any(|c| !c.is_whitespace()) { - result.push_str(prefix); - result.push_str(line); - } - result.push('\n'); - } - result -} - -/// Removes common leading whitespace from each line. -/// -/// This function will look at each non-empty line and determine the -/// maximum amount of whitespace that can be removed from all lines: -/// -/// ``` -/// use textwrap::dedent; -/// -/// assert_eq!(dedent(" -/// 1st line -/// 2nd line -/// 3rd line -/// "), " -/// 1st line -/// 2nd line -/// 3rd line -/// "); -/// ``` -pub fn dedent(s: &str) -> String { - let mut prefix = ""; - let mut lines = s.lines(); - - // We first search for a non-empty line to find a prefix. - for line in &mut lines { - let mut whitespace_idx = line.len(); - for (idx, ch) in line.char_indices() { - if !ch.is_whitespace() { - whitespace_idx = idx; - break; - } - } - - // Check if the line had anything but whitespace - if whitespace_idx < line.len() { - prefix = &line[..whitespace_idx]; - break; - } - } - - // We then continue looking through the remaining lines to - // possibly shorten the prefix. - for line in &mut lines { - let mut whitespace_idx = line.len(); - for ((idx, a), b) in line.char_indices().zip(prefix.chars()) { - if a != b { - whitespace_idx = idx; - break; - } - } - - // Check if the line had anything but whitespace and if we - // have found a shorter prefix - if whitespace_idx < line.len() && whitespace_idx < prefix.len() { - prefix = &line[..whitespace_idx]; - } - } - - // We now go over the lines a second time to build the result. - let mut result = String::new(); - for line in s.lines() { - if line.starts_with(&prefix) && line.chars().any(|c| !c.is_whitespace()) { - let (_, tail) = line.split_at(prefix.len()); - result.push_str(tail); - } - result.push('\n'); - } - - if result.ends_with('\n') && !s.ends_with('\n') { - let new_len = result.len() - 1; - result.truncate(new_len); - } - - result -} - -#[cfg(test)] -mod tests { - use super::*; - - /// Add newlines. Ensures that the final line in the vector also - /// has a newline. - fn add_nl(lines: &[&str]) -> String { - lines.join("\n") + "\n" - } - - #[test] - fn indent_empty() { - assert_eq!(indent("\n", " "), "\n"); - } - - #[test] - #[cfg_attr(rustfmt, rustfmt_skip)] - fn indent_nonempty() { - let x = vec![" foo", - "bar", - " baz"]; - let y = vec!["// foo", - "//bar", - "// baz"]; - assert_eq!(indent(&add_nl(&x), "//"), add_nl(&y)); - } - - #[test] - #[cfg_attr(rustfmt, rustfmt_skip)] - fn indent_empty_line() { - let x = vec![" foo", - "bar", - "", - " baz"]; - let y = vec!["// foo", - "//bar", - "", - "// baz"]; - assert_eq!(indent(&add_nl(&x), "//"), add_nl(&y)); - } - - #[test] - fn dedent_empty() { - assert_eq!(dedent(""), ""); - } - - #[test] - #[cfg_attr(rustfmt, rustfmt_skip)] - fn dedent_multi_line() { - let x = vec![" foo", - " bar", - " baz"]; - let y = vec![" foo", - "bar", - " baz"]; - assert_eq!(dedent(&add_nl(&x)), add_nl(&y)); - } - - #[test] - #[cfg_attr(rustfmt, rustfmt_skip)] - fn dedent_empty_line() { - let x = vec![" foo", - " bar", - " ", - " baz"]; - let y = vec![" foo", - "bar", - "", - " baz"]; - assert_eq!(dedent(&add_nl(&x)), add_nl(&y)); - } - - #[test] - #[cfg_attr(rustfmt, rustfmt_skip)] - fn dedent_blank_line() { - let x = vec![" foo", - "", - " bar", - " foo", - " bar", - " baz"]; - let y = vec!["foo", - "", - " bar", - " foo", - " bar", - " baz"]; - assert_eq!(dedent(&add_nl(&x)), add_nl(&y)); - } - - #[test] - #[cfg_attr(rustfmt, rustfmt_skip)] - fn dedent_whitespace_line() { - let x = vec![" foo", - " ", - " bar", - " foo", - " bar", - " baz"]; - let y = vec!["foo", - "", - " bar", - " foo", - " bar", - " baz"]; - assert_eq!(dedent(&add_nl(&x)), add_nl(&y)); - } - - #[test] - #[cfg_attr(rustfmt, rustfmt_skip)] - fn dedent_mixed_whitespace() { - let x = vec!["\tfoo", - " bar"]; - let y = vec!["\tfoo", - " bar"]; - assert_eq!(dedent(&add_nl(&x)), add_nl(&y)); - } - - #[test] - #[cfg_attr(rustfmt, rustfmt_skip)] - fn dedent_tabbed_whitespace() { - let x = vec!["\t\tfoo", - "\t\t\tbar"]; - let y = vec!["foo", - "\tbar"]; - assert_eq!(dedent(&add_nl(&x)), add_nl(&y)); - } - - #[test] - #[cfg_attr(rustfmt, rustfmt_skip)] - fn dedent_mixed_tabbed_whitespace() { - let x = vec!["\t \tfoo", - "\t \t\tbar"]; - let y = vec!["foo", - "\tbar"]; - assert_eq!(dedent(&add_nl(&x)), add_nl(&y)); - } - - #[test] - #[cfg_attr(rustfmt, rustfmt_skip)] - fn dedent_mixed_tabbed_whitespace2() { - let x = vec!["\t \tfoo", - "\t \tbar"]; - let y = vec!["\tfoo", - " \tbar"]; - assert_eq!(dedent(&add_nl(&x)), add_nl(&y)); - } - - #[test] - #[cfg_attr(rustfmt, rustfmt_skip)] - fn dedent_preserve_no_terminating_newline() { - let x = vec![" foo", - " bar"].join("\n"); - let y = vec!["foo", - " bar"].join("\n"); - assert_eq!(dedent(&x), y); - } -} |