Method prev

src/ore/src/lex.rs:61–68

Returns the previous character in the buffer, positioning the internal cursor to before the character. The next call to `LexBuf::next` will return the same character. # Panics Panics if `prev` is called when the internal cursor is positioned at the beginning of the buffer.

(&mut self)

    /// Panics if `prev` is called when the internal cursor is positioned at
    /// the beginning of the buffer.
    pub fn prev(&mut self) -> char {
        if let Some(c) = self.buf[..self.pos].chars().rev().next() {
            self.pos -= c.len_utf8();
            c
        } else {
            panic!("LexBuf::prev called on buffer at position 0")
        }
    }

    /// Advances the internal cursor past the next character in the buffer if
    /// the character is `ch`.