solar-parse 0.1.8

Solidity and Yul lexer and parser
Documentation 
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// UTF-8 ranges and tags for encoding characters
const TAG_CONT: u8 = 0b1000_0000;
const TAG_TWO_B: u8 = 0b1100_0000;
const TAG_THREE_B: u8 = 0b1110_0000;
const TAG_FOUR_B: u8 = 0b1111_0000;
const MAX_ONE_B: u32 = 0x80;
const MAX_TWO_B: u32 = 0x800;
const MAX_THREE_B: u32 = 0x10000;

#[inline]
const fn len_utf8(code: u32) -> usize {
    if code < MAX_ONE_B {
        1
    } else if code < MAX_TWO_B {
        2
    } else if code < MAX_THREE_B {
        3
    } else {
        4
    }
}

/// Copied from [`core::char::encode_utf8_raw`].
#[inline]
#[allow(clippy::precedence)]
pub(super) fn encode_utf8_raw(code: u32, dst: &mut [u8]) -> &mut [u8] {
    let len = len_utf8(code);
    match (len, &mut dst[..]) {
        (1, [a, ..]) => {
            *a = code as u8;
        }
        (2, [a, b, ..]) => {
            *a = (code >> 6 & 0x1F) as u8 | TAG_TWO_B;
            *b = (code & 0x3F) as u8 | TAG_CONT;
        }
        (3, [a, b, c, ..]) => {
            *a = (code >> 12 & 0x0F) as u8 | TAG_THREE_B;
            *b = (code >> 6 & 0x3F) as u8 | TAG_CONT;
            *c = (code & 0x3F) as u8 | TAG_CONT;
        }
        (4, [a, b, c, d, ..]) => {
            *a = (code >> 18 & 0x07) as u8 | TAG_FOUR_B;
            *b = (code >> 12 & 0x3F) as u8 | TAG_CONT;
            *c = (code >> 6 & 0x3F) as u8 | TAG_CONT;
            *d = (code & 0x3F) as u8 | TAG_CONT;
        }
        _ => panic!(
            "encode_utf8: need {} bytes to encode U+{:X}, but the buffer has {}",
            len,
            code,
            dst.len(),
        ),
    };
    &mut dst[..len]
}