use console::AnsiCodeIterator; /// Expand tabs like an ANSI-enabled expand(1). pub fn expand_tabs(line: &str, width: usize, cursor: &mut usize) -> String { let mut buffer = String::with_capacity(line.len() * 2); for chunk in AnsiCodeIterator::new(line) { match chunk { (text, true) => buffer.push_str(text), (mut text, false) => { while let Some(index) = text.find('\t') { // Add previous text. if index > 0 { *cursor += index; buffer.push_str(&text[0..index]); } // Add tab. let spaces = width - (*cursor % width); *cursor += spaces; buffer.push_str(&*" ".repeat(spaces)); // Next. text = &text[index + 1..text.len()]; } *cursor += text.len(); buffer.push_str(text); } } } buffer } fn try_parse_utf8_char(input: &[u8]) -> Option<(char, usize)> { let str_from_utf8 = |seq| std::str::from_utf8(seq).ok(); let decoded = input .get(0..1) .and_then(str_from_utf8) .map(|c| (c, 1)) .or_else(|| input.get(0..2).and_then(str_from_utf8).map(|c| (c, 2))) .or_else(|| input.get(0..3).and_then(str_from_utf8).map(|c| (c, 3))) .or_else(|| input.get(0..4).and_then(str_from_utf8).map(|c| (c, 4))); decoded.map(|(seq, n)| (seq.chars().next().unwrap(), n)) } pub fn replace_nonprintable(input: &[u8], tab_width: usize) -> String { let mut output = String::new(); let tab_width = if tab_width == 0 { 4 } else { tab_width }; let mut idx = 0; let len = input.len(); while idx < len { if let Some((chr, skip_ahead)) = try_parse_utf8_char(&input[idx..]) { idx += skip_ahead; match chr { // space ' ' => output.push('•'), // tab '\t' => { if tab_width == 1 { output.push('↹'); } else { output.push('├'); output.push_str(&"─".repeat(tab_width - 2)); output.push('┤'); } } // line feed '\x0A' => output.push('␊'), // carriage return '\x0D' => output.push('␍'), // null '\x00' => output.push('␀'), // bell '\x07' => output.push('␇'), // backspace '\x08' => output.push('␈'), // escape '\x1B' => output.push('␛'), // printable ASCII c if c.is_ascii_alphanumeric() || c.is_ascii_punctuation() || c.is_ascii_graphic() => { output.push(c) } // everything else c => output.push_str(&c.escape_unicode().collect::()), } } else { output.push_str(&format!("\\x{:02X}", input[idx])); idx += 1; } } output } #[test] fn test_try_parse_utf8_char() { assert_eq!(try_parse_utf8_char(&[0x20]), Some((' ', 1))); assert_eq!(try_parse_utf8_char(&[0x20, 0x20]), Some((' ', 1))); assert_eq!(try_parse_utf8_char(&[0x20, 0xef]), Some((' ', 1))); assert_eq!(try_parse_utf8_char(&[0x00]), Some(('\x00', 1))); assert_eq!(try_parse_utf8_char(&[0x1b]), Some(('\x1b', 1))); assert_eq!(try_parse_utf8_char(&[0xc3, 0xa4]), Some(('ä', 2))); assert_eq!(try_parse_utf8_char(&[0xc3, 0xa4, 0xef]), Some(('ä', 2))); assert_eq!(try_parse_utf8_char(&[0xc3, 0xa4, 0x20]), Some(('ä', 2))); assert_eq!(try_parse_utf8_char(&[0xe2, 0x82, 0xac]), Some(('€', 3))); assert_eq!( try_parse_utf8_char(&[0xe2, 0x82, 0xac, 0xef]), Some(('€', 3)) ); assert_eq!( try_parse_utf8_char(&[0xe2, 0x82, 0xac, 0x20]), Some(('€', 3)) ); assert_eq!(try_parse_utf8_char(&[0xe2, 0x88, 0xb0]), Some(('∰', 3))); assert_eq!( try_parse_utf8_char(&[0xf0, 0x9f, 0x8c, 0x82]), Some(('🌂', 4)) ); assert_eq!( try_parse_utf8_char(&[0xf0, 0x9f, 0x8c, 0x82, 0xef]), Some(('🌂', 4)) ); assert_eq!( try_parse_utf8_char(&[0xf0, 0x9f, 0x8c, 0x82, 0x20]), Some(('🌂', 4)) ); assert_eq!(try_parse_utf8_char(&[]), None); assert_eq!(try_parse_utf8_char(&[0xef]), None); assert_eq!(try_parse_utf8_char(&[0xef, 0x20]), None); assert_eq!(try_parse_utf8_char(&[0xf0, 0xf0]), None); }