---
name: "unicode::wordbreak_callback_base"
section: "3"
platform: "linux"
package: "libcourier-unicode-dev"
version: "2.3.2-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/unicode::wordbreak_callback_base"
---

# unicode::wordbreak\_callback\_base(3)

unicode word-breaking rules

## NAME

unicode::wordbreak\_callback\_base, unicode::wordbreak - unicode word-breaking rules

## SYNOPSIS

```
#include <courier-unicode.h>
class wordbreak : public unicode::wordbreak_callback_base {
public:
    using unicode::wordbreak_callback_base::operator<<;
    using unicode::wordbreak_callback_base::operator();
    int callback(bool flag)
    {
        // ...
    }
};
char32_t c;
std::u32string buf;
wordbreak compute_wordbreak;
compute_wordbreak << c;
compute_wordbreak(buf);
compute_wordbreak(buf.begin(), buf.end());
compute_wordbreak.finish();
// ...
unicode_wordbreakscan scan;
scan << c;
size_t nchars=scan.finish();
```

## DESCRIPTION

unicode::wordbreak\_callback\_base is a C++ binding for the unicode word-breaking rule implementation described in [**unicode\_word\_break**(3)](/unicode_word_break/3.md).

Subclass unicode::wordbreak\_callback\_base and implement callback() that's virtually inherited from unicode::wordbreak\_callback\_base. The callback() callback function receives the output values from the word-breaking algorithm, namely a bool indicating whether a word break exists before the unicode character in the underlying input sequence.

callback() should return 0. A non-zero return reports an error, that stops the word-breaking algorithm. See [**unicode\_word\_break**(3)](/unicode_word_break/3.md) for more information.

The input unicode characters for the word-breaking algorithm are provided by the \<\< operator, one unicode character at a time; or by the () operator, passing either a container, or a beginning and an ending iterator value for an input sequence of unicode characters. finish() indicates the end of the unicode character sequence.

unicode::wordbreakscan is a C++ binding for the **unicode\_wbscan\_init**(), **unicode\_wbscan\_next**() and **unicode\_wbscan\_end** methods described in [**unicode\_word\_break**(3)](/unicode_word_break/3.md). Its \<\< iterates over the unicode characters, and finish() indicates the number of characters before the first unicode word break. The \<\< iterator returns a bool indicating when the first word break has already been found, so further calls are not necessary.

## SEE ALSO

[**courier-unicode**(7)](/courier-unicode/7.md), [**unicode\_word\_break**(3)](/unicode_word_break/3.md).

## AUTHOR

**Sam Varshavchik**

Author