[Rust] generate slice ref setter in Encoder for fixed size array

[wbprime]

Releated to #1021

For field of primitive array type, generate 2 more setter methods in its Encoder:

1. one named with _at_most_N_items_from_slice to enable copy as more as items less than array length to encoding bytes buffer.
2. one named with _at_most_N_items_from_slice to enable copy as more as items less than array length to encoding bytes buffer. If no enough items provided, will continue padding using a given value provided via a third parameter.

Generated methods differs on backing primitive type for u8 and non u8.

If there exists following SBE definition:

<type name="Fixed4U8" length="4" primitiveType="uint8" semanticType="Data"/>
<type name="Fixed4i32" length="4" primitiveType="int32" />

<field name="fixedU8" id="11" type="Fixed4U8"/>
<field name="fixedi32" id="23" type="Fixed4i32"/>

Then following new methods would be generated:

// primitive array field 'fixedU8'
/// - min value: 0
/// - max value: 254
/// - null value: 255
/// - characterEncoding: null
/// - semanticType: Data
/// - encodedOffset: 0
/// - encodedLength: 4
/// - version: 0
#[inline]
pub fn fixed_u8(&mut self, value: &[u8; 4]) {
    let offset = self.offset;
    let buf = self.get_buf_mut();
    buf.put_bytes_at(offset, value);
}

/// primitive array field 'fixedU8': copy at most 4 items from slice without padding
/// - min value: 0
/// - max value: 254
/// - null value: 255
/// - characterEncoding: null
/// - semanticType: Data
/// - encodedOffset: 0
/// - encodedLength: 4
/// - version: 0
#[inline]
pub fn fixed_u8_at_most_4_items_from_slice(&mut self, value: &[u8]) {
    let offset = self.offset;
    let buf = self.get_buf_mut();
    match value.len() {
        0 => {
            // Copy all 0 items from 'value' into 'fixedU8' of [u8; 4]

            // Leave 4 left items unchanged
        }
        1 => {
            // Copy all 1 items from 'value' into 'fixedU8' of [u8; 4]
            buf.put_slice_at(offset, value);

            // Leave 3 left items unchanged
        }
        2 => {
            // Copy all 2 items from 'value' into 'fixedU8' of [u8; 4]
            buf.put_slice_at(offset, value);

            // Leave 2 left items unchanged
        }
        3 => {
            // Copy all 3 items from 'value' into 'fixedU8' of [u8; 4]
            buf.put_slice_at(offset, value);

            // Leave 1 left items unchanged
        }
        _ => {
            // Copy all 4 items from 'value' into 'fixedU8' of [u8; 4]
            buf.put_slice_at(offset, value);

            // Leave 0 left items unchanged
        }
    }
}

/// primitive array field 'fixedU8': copy at most 4 items from slice with padding
/// - min value: 0
/// - max value: 254
/// - null value: 255
/// - characterEncoding: null
/// - semanticType: Data
/// - encodedOffset: 0
/// - encodedLength: 4
/// - version: 0
#[inline]
pub fn fixed_u8_at_most_4_items_from_slice_padded(&mut self, value: &[u8], padded: u8) {
    let offset = self.offset;
    let buf = self.get_buf_mut();
    match value.len() {
        0 => {
            // Copy all 0 items from 'value' into 'fixedU8' of [u8; 4]

            // Pad 4 left items of 'fixedU8' with parameter "padded"
            buf.put_bytes_at(offset, &[padded; 4]);
        }
        1 => {
            // Copy all 1 items from 'value' into 'fixedU8' of [u8; 4]
            buf.put_slice_at(offset, value);

            // Pad 3 left items of 'fixedU8' with parameter "padded"
            buf.put_bytes_at(offset + 1, &[padded; 3]);
        }
        2 => {
            // Copy all 2 items from 'value' into 'fixedU8' of [u8; 4]
            buf.put_slice_at(offset, value);

            // Pad 2 left items of 'fixedU8' with parameter "padded"
            buf.put_bytes_at(offset + 2, &[padded; 2]);
        }
        3 => {
            // Copy all 3 items from 'value' into 'fixedU8' of [u8; 4]
            buf.put_slice_at(offset, value);

            // Pad 1 left items of 'fixedU8' with parameter "padded"
            buf.put_bytes_at(offset + 3, &[padded; 1]);
        }
        _ => {
            // Copy all 4 items from 'value' into 'fixedU8' of [u8; 4]
            buf.put_slice_at(offset, value);

            // Pad 0 left items of 'fixedU8' with parameter "padded"
        }
    }
}

/// primitive array field 'fixedi32'
/// - min value: -2147483647
/// - max value: 2147483647
/// - null value: -2147483648
/// - characterEncoding: null
/// - semanticType: null
/// - encodedOffset: 4
/// - encodedLength: 16
/// - version: 0
#[inline]
pub fn fixedi_32(&mut self, value: &[i32; 4]) {
    let offset = self.offset + 4;
    let buf = self.get_buf_mut();
    buf.put_i32_at(offset, value[0]);
    buf.put_i32_at(offset + 4, value[1]);
    buf.put_i32_at(offset + 8, value[2]);
    buf.put_i32_at(offset + 12, value[3]);
}

/// primitive array field 'fixedi32': copy at most 4 items from slice without padding
/// - min value: -2147483647
/// - max value: 2147483647
/// - null value: -2147483648
/// - characterEncoding: null
/// - semanticType: null
/// - encodedOffset: 4
/// - encodedLength: 16
/// - version: 0
#[inline]
pub fn fixedi_32_at_most_4_items_from_slice(&mut self, value: &[i32]) {
    let offset = self.offset + 4;
    let buf = self.get_buf_mut();
    match value.len() {
        0 => {
            // Copy all 0 items from 'value' into 'fixedi32' of [i32; 4]

            // Leave 4 left items unchanged
        }
        1 => {
            // Copy all 1 items from 'value' into 'fixedi32' of [i32; 4]
            buf.put_i32_at(offset, value[0]);

            // Leave 3 left items unchanged
        }
        2 => {
            // Copy all 2 items from 'value' into 'fixedi32' of [i32; 4]
            buf.put_i32_at(offset, value[0]);
            buf.put_i32_at(offset + 4, value[1]);

            // Leave 2 left items unchanged
        }
        3 => {
            // Copy all 3 items from 'value' into 'fixedi32' of [i32; 4]
            buf.put_i32_at(offset, value[0]);
            buf.put_i32_at(offset + 4, value[1]);
            buf.put_i32_at(offset + 8, value[2]);

            // Leave 1 left items unchanged
        }
        _ => {
            // Copy all 4 items from 'value' into 'fixedi32' of [i32; 4]
            buf.put_i32_at(offset, value[0]);
            buf.put_i32_at(offset + 4, value[1]);
            buf.put_i32_at(offset + 8, value[2]);
            buf.put_i32_at(offset + 12, value[3]);

            // Leave 0 left items unchanged
        }
    }
}

/// primitive array field 'fixedi32': copy at most 4 items from slice with padding
/// - min value: -2147483647
/// - max value: 2147483647
/// - null value: -2147483648
/// - characterEncoding: null
/// - semanticType: null
/// - encodedOffset: 4
/// - encodedLength: 16
/// - version: 0
#[inline]
pub fn fixedi_32_at_most_4_items_from_slice_padded(&mut self, value: &[i32], padded: i32) {
    let offset = self.offset + 4;
    let buf = self.get_buf_mut();
    match value.len() {
        0 => {
            // Copy all 0 items from 'value' into 'fixedi32' of [i32; 4]

            // Pad 4 left items of 'fixedi32' with parameter "padded"
            buf.put_i32_at(offset, padded);
            buf.put_i32_at(offset + 4, padded);
            buf.put_i32_at(offset + 8, padded);
            buf.put_i32_at(offset + 12, padded);
        }
        1 => {
            // Copy all 1 items from 'value' into 'fixedi32' of [i32; 4]
            buf.put_i32_at(offset, value[0]);

            // Pad 3 left items of 'fixedi32' with parameter "padded"
            buf.put_i32_at(offset + 4, padded);
            buf.put_i32_at(offset + 8, padded);
            buf.put_i32_at(offset + 12, padded);
        }
        2 => {
            // Copy all 2 items from 'value' into 'fixedi32' of [i32; 4]
            buf.put_i32_at(offset, value[0]);
            buf.put_i32_at(offset + 4, value[1]);

            // Pad 2 left items of 'fixedi32' with parameter "padded"
            buf.put_i32_at(offset + 8, padded);
            buf.put_i32_at(offset + 12, padded);
        }
        3 => {
            // Copy all 3 items from 'value' into 'fixedi32' of [i32; 4]
            buf.put_i32_at(offset, value[0]);
            buf.put_i32_at(offset + 4, value[1]);
            buf.put_i32_at(offset + 8, value[2]);

            // Pad 1 left items of 'fixedi32' with parameter "padded"
            buf.put_i32_at(offset + 12, padded);
        }
        _ => {
            // Copy all 4 items from 'value' into 'fixedi32' of [i32; 4]
            buf.put_i32_at(offset, value[0]);
            buf.put_i32_at(offset + 4, value[1]);
            buf.put_i32_at(offset + 8, value[2]);
            buf.put_i32_at(offset + 12, value[3]);

            // Pad 0 left items of 'fixedi32' with parameter "padded"
        }
    }
}

[wbprime]

Closed as is deprecated by #1040 from @mward .