led/src/buffer/line.rs

602 lines
16 KiB
Rust

#![allow(dead_code)]
use std::mem;
use std::str::Graphemes;
use string_utils::{grapheme_count, grapheme_pos_to_byte_pos, is_line_ending};
/// A single line of text
pub struct Line {
text: Vec<u8>, // The text data, stored as UTF8
pub ending: LineEnding, // The type of line ending, if any
}
impl Line {
/// Creates a new empty Line
pub fn new() -> Line {
Line {
text: Vec::new(),
ending: LineEnding::None,
}
}
/// Creates a new Line from a str.
pub fn new_from_str(text: &str) -> Line {
// Initialize Line
let mut tl = Line {
text: Vec::with_capacity(text.len()),
ending: LineEnding::None,
};
// Copy text data, stopping on a line ending if any is found
for g in text.graphemes(true) {
match g {
//==============
// Line endings
//==============
// CRLF
"\u{000D}\u{000A}" => {
tl.ending = LineEnding::CRLF;
break;
},
// LF
"\u{000A}" => {
tl.ending = LineEnding::LF;
break;
},
// VT
"\u{000B}" => {
tl.ending = LineEnding::VT;
break;
},
// FF
"\u{000C}" => {
tl.ending = LineEnding::FF;
break;
},
// CR
"\u{000D}" => {
tl.ending = LineEnding::CR;
break;
},
// NEL
"\u{0085}" => {
tl.ending = LineEnding::NEL;
break;
},
// LS
"\u{2028}" => {
tl.ending = LineEnding::LS;
break;
},
// PS
"\u{2029}" => {
tl.ending = LineEnding::PS;
break;
},
//==================
// Other characters
//==================
_ => {
for b in g.bytes() {
tl.text.push(b);
}
}
}
}
// Done!
return tl;
}
/// Returns the total number of unicode graphemes in the line
pub fn grapheme_count(&self) -> uint {
let mut count = grapheme_count(self.as_str());
match self.ending {
LineEnding::None => {},
_ => {count += 1;}
}
return count;
}
/// Returns the total number of unicode graphemes in the line,
/// not counting the line ending grapheme, if any.
pub fn grapheme_count_sans_line_ending(&self) -> uint {
grapheme_count(self.as_str())
}
/// Returns an immutable string slice into the text block's memory
pub fn as_str<'a>(&'a self) -> &'a str {
unsafe {
mem::transmute(self.text.as_slice())
}
}
/// Inserts `text` at grapheme index `pos`.
/// NOTE: panics if it encounters a line ending in the text.
pub fn insert_text(&mut self, text: &str, pos: uint) {
// Find insertion position in bytes
let byte_pos = grapheme_pos_to_byte_pos(self.as_str(), pos);
// Grow data size
self.text.grow(text.len(), 0);
// Move old bytes forward
let mut from = self.text.len() - text.len();
let mut to = self.text.len();
while from > byte_pos {
from -= 1;
to -= 1;
self.text[to] = self.text[from];
}
// Copy new bytes in
let mut i = byte_pos;
for g in text.graphemes(true) {
if is_line_ending(g) {
panic!("Line::insert_text(): line ending in inserted text.");
}
for b in g.bytes() {
self.text[i] = b;
i += 1
}
}
}
/// Remove the text between grapheme positions 'pos_a' and 'pos_b'.
pub fn remove_text(&mut self, pos_a: uint, pos_b: uint) {
// Bounds checks
if pos_a > pos_b {
panic!("Line::remove_text(): pos_a must be less than or equal to pos_b.");
}
// Find removal positions in bytes
let byte_pos_a = grapheme_pos_to_byte_pos(self.as_str(), pos_a);
let byte_pos_b = grapheme_pos_to_byte_pos(self.as_str(), pos_b);
// Move bytes to fill in the gap left by the removed bytes
let mut from = byte_pos_b;
let mut to = byte_pos_a;
while from < self.text.len() {
self.text[to] = self.text[from];
from += 1;
to += 1;
}
// Remove data from the end
let final_text_size = self.text.len() + byte_pos_a - byte_pos_b;
self.text.truncate(final_text_size);
}
/// Insert a line break into the line, splitting it into two.
/// This line stays as the first part of the split. The second
/// part is returned.
pub fn split(&mut self, ending: LineEnding, pos: uint) -> Line {
let mut other = Line::new();
// Inserting at very beginning: special cased for efficiency
if pos == 0 {
mem::swap(self, &mut other);
self.ending = ending;
}
// Otherwise, general case
else {
// Find the byte index to split at
let byte_pos = grapheme_pos_to_byte_pos(self.as_str(), pos);
// Copy the elements after the split index to the second line
other.text.push_all(self.text.slice_from_or_fail(&byte_pos));
// Truncate the first line
self.text.truncate(byte_pos);
// Set the line endings appropriately
other.ending = self.ending;
self.ending = ending;
}
return other;
}
/// Returns an iterator over the graphemes of the line
pub fn grapheme_iter<'a>(&'a self) -> LineGraphemeIter<'a> {
LineGraphemeIter {
graphemes: self.as_str().graphemes(true),
ending: self.ending,
done: false,
}
}
/// Returns an iterator over the graphemes of the line
pub fn grapheme_iter_at_index<'a>(&'a self, index: uint) -> LineGraphemeIter<'a> {
let temp: &str = unsafe{mem::transmute(self.text.as_slice())};
let mut iter = LineGraphemeIter {
graphemes: temp.graphemes(true),
ending: self.ending,
done: false,
};
for _ in range(0, index) {
iter.next();
}
return iter;
}
}
/// Represents one of the valid Unicode line endings.
/// Also acts as an index into `LINE_ENDINGS`.
#[deriving(PartialEq, Copy)]
pub enum LineEnding {
None = 0, // No line ending
CRLF = 1, // CarriageReturn followed by LineFeed
LF = 2, // U+000A -- LineFeed
VT = 3, // U+000B -- VerticalTab
FF = 4, // U+000C -- FormFeed
CR = 5, // U+000D -- CarriageReturn
NEL = 6, // U+0085 -- NextLine
LS = 7, // U+2028 -- Line Separator
PS = 8, // U+2029 -- ParagraphSeparator
}
pub fn str_to_line_ending(g: &str) -> LineEnding {
match g {
//==============
// Line endings
//==============
// CRLF
"\u{000D}\u{000A}" => {
return LineEnding::CRLF;
},
// LF
"\u{000A}" => {
return LineEnding::LF;
},
// VT
"\u{000B}" => {
return LineEnding::VT;
},
// FF
"\u{000C}" => {
return LineEnding::FF;
},
// CR
"\u{000D}" => {
return LineEnding::CR;
},
// NEL
"\u{0085}" => {
return LineEnding::NEL;
},
// LS
"\u{2028}" => {
return LineEnding::LS;
},
// PS
"\u{2029}" => {
return LineEnding::PS;
},
// Not a line ending
_ => {
return LineEnding::None;
}
}
}
/// An array of string literals corresponding to the possible
/// unicode line endings.
pub const LINE_ENDINGS: [&'static str, ..9] = ["",
"\u{000D}\u{000A}",
"\u{000A}",
"\u{000B}",
"\u{000C}",
"\u{000D}",
"\u{0085}",
"\u{2028}",
"\u{2029}"
];
/// An iterator over the graphemes of a Line
pub struct LineGraphemeIter<'a> {
graphemes: Graphemes<'a>,
ending: LineEnding,
done: bool,
}
impl<'a> Iterator<&'a str> for LineGraphemeIter<'a> {
fn next(&mut self) -> Option<&'a str> {
if self.done {
return None;
}
else {
let g = self.graphemes.next();
if let Some(_) = g {
return g;
}
else {
self.done = true;
if self.ending == LineEnding::None {
return None;
}
else {
return Some(LINE_ENDINGS[self.ending as uint]);
}
}
}
}
}
//=========================================================================
// Line tests
//=========================================================================
#[test]
fn new_text_line() {
let tl = Line::new();
assert!(tl.text.len() == 0);
assert!(tl.ending == LineEnding::None);
}
#[test]
fn new_text_line_from_str() {
let tl = Line::new_from_str("Hello!");
assert!(tl.text.len() == 6);
assert!(tl.text[0] == ('H' as u8));
assert!(tl.text[1] == ('e' as u8));
assert!(tl.text[2] == ('l' as u8));
assert!(tl.text[3] == ('l' as u8));
assert!(tl.text[4] == ('o' as u8));
assert!(tl.text[5] == ('!' as u8));
assert!(tl.ending == LineEnding::None);
}
#[test]
fn new_text_line_from_empty_str() {
let tl = Line::new_from_str("");
assert!(tl.text.len() == 0);
assert!(tl.ending == LineEnding::None);
}
#[test]
fn new_text_line_from_str_with_lf() {
let tl = Line::new_from_str("Hello!\n");
assert!(tl.text.len() == 6);
assert!(tl.text[0] == ('H' as u8));
assert!(tl.text[1] == ('e' as u8));
assert!(tl.text[2] == ('l' as u8));
assert!(tl.text[3] == ('l' as u8));
assert!(tl.text[4] == ('o' as u8));
assert!(tl.text[5] == ('!' as u8));
assert!(tl.ending == LineEnding::LF);
}
#[test]
fn new_text_line_from_str_with_crlf() {
let tl = Line::new_from_str("Hello!\r\n");
assert!(tl.text.len() == 6);
assert!(tl.text[0] == ('H' as u8));
assert!(tl.text[1] == ('e' as u8));
assert!(tl.text[2] == ('l' as u8));
assert!(tl.text[3] == ('l' as u8));
assert!(tl.text[4] == ('o' as u8));
assert!(tl.text[5] == ('!' as u8));
assert!(tl.ending == LineEnding::CRLF);
}
#[test]
fn new_text_line_from_str_with_crlf_and_too_long() {
let tl = Line::new_from_str("Hello!\r\nLa la la la");
assert!(tl.text.len() == 6);
assert!(tl.text[0] == ('H' as u8));
assert!(tl.text[1] == ('e' as u8));
assert!(tl.text[2] == ('l' as u8));
assert!(tl.text[3] == ('l' as u8));
assert!(tl.text[4] == ('o' as u8));
assert!(tl.text[5] == ('!' as u8));
assert!(tl.ending == LineEnding::CRLF);
}
#[test]
fn text_line_insert_text() {
let mut tl = Line::new_from_str("Hello!\r\n");
tl.insert_text(" world", 5);
assert!(tl.text.len() == 12);
assert!(tl.text[0] == ('H' as u8));
assert!(tl.text[1] == ('e' as u8));
assert!(tl.text[2] == ('l' as u8));
assert!(tl.text[3] == ('l' as u8));
assert!(tl.text[4] == ('o' as u8));
assert!(tl.text[5] == (' ' as u8));
assert!(tl.text[6] == ('w' as u8));
assert!(tl.text[7] == ('o' as u8));
assert!(tl.text[8] == ('r' as u8));
assert!(tl.text[9] == ('l' as u8));
assert!(tl.text[10] == ('d' as u8));
assert!(tl.text[11] == ('!' as u8));
assert!(tl.ending == LineEnding::CRLF);
}
#[test]
fn text_line_remove_text() {
let mut tl = Line::new_from_str("Hello world!\r\n");
tl.remove_text(5, 11);
assert!(tl.text.len() == 6);
assert!(tl.text[0] == ('H' as u8));
assert!(tl.text[1] == ('e' as u8));
assert!(tl.text[2] == ('l' as u8));
assert!(tl.text[3] == ('l' as u8));
assert!(tl.text[4] == ('o' as u8));
assert!(tl.text[5] == ('!' as u8));
assert!(tl.ending == LineEnding::CRLF);
}
#[test]
fn text_line_split() {
let mut tl1 = Line::new_from_str("Hello world!\r\n");
let tl2 = tl1.split(LineEnding::LF, 5);
assert!(tl1.text.len() == 5);
assert!(tl1.text[0] == ('H' as u8));
assert!(tl1.text[1] == ('e' as u8));
assert!(tl1.text[2] == ('l' as u8));
assert!(tl1.text[3] == ('l' as u8));
assert!(tl1.text[4] == ('o' as u8));
assert!(tl1.ending == LineEnding::LF);
assert!(tl2.text.len() == 7);
assert!(tl2.text[0] == (' ' as u8));
assert!(tl2.text[1] == ('w' as u8));
assert!(tl2.text[2] == ('o' as u8));
assert!(tl2.text[3] == ('r' as u8));
assert!(tl2.text[4] == ('l' as u8));
assert!(tl2.text[5] == ('d' as u8));
assert!(tl2.text[6] == ('!' as u8));
assert!(tl2.ending == LineEnding::CRLF);
}
#[test]
fn text_line_split_beginning() {
let mut tl1 = Line::new_from_str("Hello!\r\n");
let tl2 = tl1.split(LineEnding::LF, 0);
assert!(tl1.text.len() == 0);
assert!(tl1.ending == LineEnding::LF);
assert!(tl2.text.len() == 6);
assert!(tl2.text[0] == ('H' as u8));
assert!(tl2.text[1] == ('e' as u8));
assert!(tl2.text[2] == ('l' as u8));
assert!(tl2.text[3] == ('l' as u8));
assert!(tl2.text[4] == ('o' as u8));
assert!(tl2.text[5] == ('!' as u8));
assert!(tl2.ending == LineEnding::CRLF);
}
//=========================================================================
// LineGraphemeIter tests
//=========================================================================
#[test]
fn text_line_grapheme_iter() {
let tl = Line::new_from_str("Hello!");
let mut iter = tl.grapheme_iter();
assert!(iter.next() == Some("H"));
assert!(iter.next() == Some("e"));
assert!(iter.next() == Some("l"));
assert!(iter.next() == Some("l"));
assert!(iter.next() == Some("o"));
assert!(iter.next() == Some("!"));
assert!(iter.next() == None);
}
#[test]
fn text_line_grapheme_iter_with_lf() {
let tl = Line::new_from_str("Hello!\n");
let mut iter = tl.grapheme_iter();
assert!(iter.next() == Some("H"));
assert!(iter.next() == Some("e"));
assert!(iter.next() == Some("l"));
assert!(iter.next() == Some("l"));
assert!(iter.next() == Some("o"));
assert!(iter.next() == Some("!"));
assert!(iter.next() == Some("\n"));
assert!(iter.next() == None);
}
#[test]
fn text_line_grapheme_iter_with_crlf() {
let tl = Line::new_from_str("Hello!\r\n");
let mut iter = tl.grapheme_iter();
assert!(iter.next() == Some("H"));
assert!(iter.next() == Some("e"));
assert!(iter.next() == Some("l"));
assert!(iter.next() == Some("l"));
assert!(iter.next() == Some("o"));
assert!(iter.next() == Some("!"));
assert!(iter.next() == Some("\r\n"));
assert!(iter.next() == None);
}
#[test]
fn text_line_grapheme_iter_at_index() {
let tl = Line::new_from_str("Hello!");
let mut iter = tl.grapheme_iter_at_index(2);
assert!(iter.next() == Some("l"));
assert!(iter.next() == Some("l"));
assert!(iter.next() == Some("o"));
assert!(iter.next() == Some("!"));
assert!(iter.next() == None);
}
#[test]
fn text_line_grapheme_iter_at_index_past_end() {
let tl = Line::new_from_str("Hello!");
let mut iter = tl.grapheme_iter_at_index(10);
assert!(iter.next() == None);
}
#[test]
fn text_line_grapheme_iter_at_index_at_lf() {
let tl = Line::new_from_str("Hello!\n");
let mut iter = tl.grapheme_iter_at_index(6);
assert!(iter.next() == Some("\n"));
assert!(iter.next() == None);
}