prevGraphemeClusterBreak

Return the previous extended grapheme cluster break in a string before a specified position.

Usage

var prevGraphemeClusterBreak = require( '@stdlib/string/prev-grapheme-cluster-break' );

prevGraphemeClusterBreak( string[, fromIndex] )

Returns the previous extended grapheme cluster break in a string before a specified position.

var out = prevGraphemeClusterBreak( 'last man standing' );
// returns 15

By default, the last extended grapheme cluster break in the string is returned. For the previous extended grapheme cluster break before a specified position in the string, provide a fromIndex.

var out = prevGraphemeClusterBreak( 'last man standing', 4 );
// returns 3

Notes

If string is an empty string, the function returns -1 irrespective of fromIndex.
If there is no extended grapheme cluster break before fromIndex, the function returns -1.
Note that fromIndex does not refer to a visual character position, but to an index in the ordered sequence of UTF-16 code units.

Examples

var prevGraphemeClusterBreak = require( '@stdlib/string/prev-grapheme-cluster-break' );

console.log( prevGraphemeClusterBreak( 'last man standing', 4 ) );
// => 3

console.log( prevGraphemeClusterBreak( 'presidential election', 8 ) );
// => 7

console.log( prevGraphemeClusterBreak( 'अनुच्छेद', 2 ) );
// => 0

console.log( prevGraphemeClusterBreak( '🌷', 1 ) );
// => -1

CLI

Usage

Usage: prev-grapheme-cluster-break [options] [<string>]

Options:

  -h,    --help                Print this message.
  -V,    --version             Print the package version.
         --fromIndex index     Position in string. Default: string.length-1.

Examples

$ prev-grapheme-cluster-break --fromIndex=2 अनुच्छेद
0

To use as a standard stream,

$ echo -n 'अनुच्छेद' | prev-grapheme-cluster-break --fromIndex=2
0