Crate line_column 

Simple calculate lines and columns of str index

Use LF (0x0A) to split newline, also compatible with CRLF (0x0D 0x0A)

Newline char line number is current line

For index and char_index:

• When index exceeds the string length, return string length
• When column exceeds the newline char, return the index of the newline char
• When column by zero, return previous char index

NOTE: This crate is lightweight and simple calculations. For high-performance and frequent calculations, please use line-index crate.

Examples

Byte index to line number:

use line_column::line_column;

assert_eq!(line_column("", 0),       (1, 1));
assert_eq!(line_column("a", 0),      (1, 1));
assert_eq!(line_column("a", 1),      (1, 2));
assert_eq!(line_column("ab", 1),     (1, 2));
assert_eq!(line_column("a\n", 1),    (1, 2));
assert_eq!(line_column("a\n", 2),    (2, 1));
assert_eq!(line_column("a\nb", 2),   (2, 1));
assert_eq!(line_column("a\r\nb", 2), (1, 3));
assert_eq!(line_column("a\r\nb", 3), (2, 1));

Character index to line number:

use line_column::char_line_column;

assert_eq!(char_line_column("", 0),         (1, 1));
assert_eq!(char_line_column("a", 0),        (1, 1));
assert_eq!(char_line_column("a", 1),        (1, 2));
assert_eq!(char_line_column("ab", 1),       (1, 2));
assert_eq!(char_line_column("😀\n", 1),     (1, 2));
assert_eq!(char_line_column("😀\n", 2),     (2, 1));
assert_eq!(char_line_column("😀\n❓", 2),   (2, 1));
assert_eq!(char_line_column("😀\n❓", 2),   (2, 1));

Line number to byte index:

use line_column::index;

assert_eq!(index("", 1, 1),             0);
assert_eq!(index("a", 1, 1),            0);
assert_eq!(index("a", 1, 2),            1);
assert_eq!(index("a\n", 1, 2),          1);
assert_eq!(index("a\n", 2, 1),          2);
assert_eq!(index("a\nx", 2, 2),         3);
assert_eq!(index("你好\n世界", 1, 2),   3); // byte index
assert_eq!(index("你好\n世界", 1, 3),   6);
assert_eq!(index("你好\n世界", 2, 1),   7);

Line number to character index:

use line_column::char_index;

assert_eq!(char_index("", 1, 1),            0);
assert_eq!(char_index("a", 1, 1),           0);
assert_eq!(char_index("你好\n世界", 1, 2),  1);
assert_eq!(char_index("你好\n世界", 1, 3),  2);
assert_eq!(char_index("你好\n世界", 2, 1),  3);

The end of string is considered a character:

use line_column::*;

assert_eq!(index("", 1, 1),             0);
assert_eq!(index("a", 1, 2),            1);
assert_eq!(char_index("", 1, 1),        0);
assert_eq!(char_index("a", 1, 2),       1);
assert_eq!(line_column("", 0),          (1, 1));
assert_eq!(line_column("a", 1),         (1, 2));
assert_eq!(char_line_column("", 0),     (1, 1));
assert_eq!(char_line_column("a", 1),    (1, 2));

Features

• span: Out of the box Span for storing source code and text range.
• sync: Span uses sync structs

Modules

spanspan

Out of the box Span for storing source code and text range.

Functions

char_index

Get str char index of line and column

char_line_column

Get tuple of line and column, use char index

char_line_columns

Get multiple pairs of lines and columns may be faster

index

Get str byte index of line and column

line_column

Get tuple of line and column, use byte index

line_columns

Get multiple pairs of lines and columns may be faster

line_columns_unchecked

Get multiple of lines and columns may be faster