Crate cj_bitmask_vec

Crate cj_bitmask_vec 

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BitmaskVec is a vector that pairs bitmasks with T. Bitmasks u8 through u128 are supported.

Items can be added with or without supplying bitmasks. The bitmask will default to zero if not supplied.

Filtering iterator using bitmasks:

    use cj_bitmask_vec::prelude::*;
    
    let mut v = BitmaskVec::<u8, i32>::new();
    // Bitmasks hold whatever meaning the developer gives them.
    // In this example any u8 is a valid bitmask.
    //                (bitmask)  (T)      
    v.push_with_mask(0b00000000, 100);
    v.push_with_mask(0b00000010, 101);
    v.push_with_mask(0b00000011, 102);
    v.push_with_mask(0b00000100, 103);
    v.push_with_mask(0b00000110, 104);
    v.push(105);  // <- bitmask will default to zero
    // or an easier way to add items   
    v += (0b00000000, 106);
    v += (0b00010000, 107);
    v += (0b00100000, 108);
    v += (0b00000100, 109);
    v += (0b10000001, 110);
    v += (0b00000001, 111);
    v += (0b00000000, 112);
    v += 113; // <- bitmask will default to zero

    assert_eq!(v[6], 106);
     
    // here we're going to iterate over all items that have bitmask bit 1 set
    let mut count = 0;
    let mut iter = v.iter_with_mask();
    //                                (mask with bit 1 set)
    //                                               V
    while let Some(pair) = iter.filter_mask(&0b00000010) {
        // only items 101, 102, and 104 in the Vec above have
        // bitmask bit 1 set.
        assert!([101, 102, 104].contains(&pair.item));
        count += 1;
    }
    assert_eq!(count, 3);

Iterating over T:

    use cj_bitmask_vec::prelude::*;
     
    let mut v = BitmaskVec::<u8, i32>::new();
    v.push_with_mask(0b00000000, 100);
    v.push_with_mask(0b00000010, 101);
    v.push_with_mask(0b00000010, 102);
    v.push_with_mask(0b00000110, 103);
    v.push_with_mask(0b00000001, 104);
    v.push_with_mask(0b00000001, 105);
    v.push_with_mask(0b00000000, 106);

    let mut total = 0;
    // iter excludes the bitmask
    for x in v.iter() {
        total += x;
    }
    assert_eq!(total, 721);

Iterating over T and bitmask:

    use cj_bitmask_vec::prelude::*;
    use cj_common::prelude::CjMatchesMask;
     
    let mut v = BitmaskVec::<u8, i32>::new();
    v.push_with_mask(0b00000000, 100);
    v.push_with_mask(0b00000010, 101);
    v.push_with_mask(0b00000010, 102);
    v.push_with_mask(0b00000110, 103);
    v.push_with_mask(0b00000001, 104);
    v.push_with_mask(0b00000001, 105);
    v.push_with_mask(0b00000000, 106);

    let mut total = 0;
    for x in v.iter_with_mask() {
        if x.matches_mask(&0b00000010) {
            total += x.item;
        }
    }
    assert_eq!(total, 306);

Mutably iterating over T:

    use cj_bitmask_vec::prelude::*;

    let mut v = BitmaskVec::<u8, i32>::new();
    v.push_with_mask(0b00000000, 100);
    v.push_with_mask(0b00000010, 101);
    v.push_with_mask(0b00000010, 102);
    v.push_with_mask(0b00000100, 103);
    v.push_with_mask(0b00000011, 104);
    v.push_with_mask(0b00000001, 105);
    v.push_with_mask(0b00000000, 106);

    let mut total = 0;
    // iter_mut excludes the bitmask
    let x = v.iter_mut();
    for z in x {
        // here we modify T
        total += *z;
        *z *= 2;
    }

    // verify the changes from above
    let mut total_2 = 0;
    let x = v.iter();
    for z in x {
        total_2 += *z;
    }

    assert_eq!(total_2, total * 2);

Mutably iterating over T and bitmask:

    use cj_bitmask_vec::prelude::*;
    use cj_common::prelude::{Bitflag, CjMatchesMask};

    let mut v = BitmaskVec::<u8, i32>::new();
    v.push_with_mask(0b00000000, 100);
    v.push_with_mask(0b00000010, 101);
    v.push_with_mask(0b00000010, 102);
    v.push_with_mask(0b00000100, 103);
    v.push_with_mask(0b00000011, 104);
    v.push_with_mask(0b00000001, 105);
    v.push_with_mask(0b00000000, 106);

    let mut total = 0;
    let x = v.iter_with_mask_mut();
    for z in x {
        total += z.item;
        // here we modify T
        z.item *= 2;

        // here we modify the 8th bit of the bitmask.
        // - Note that set_bit() only modifies a single bit,
        //   leaving the rest of the bitmask unchanged.
        z.bitmask.set_bit(7, true);
    }
     
    // verify the changes from above
    let mut total_2 = 0;
    let x = v.iter_with_mask();
    for z in x {
        total_2 += z.item;
        // test that the 8th bit is now set.
        assert!(z.matches_mask(&0b10000000));
    }
    // test that T was modified
    assert_eq!(total_2, total * 2);

Modulesยง

cj_bitmask_item
Struct that pairs bitmask with T
cj_bitmask_vec
Vec of BitmaskItem
prelude
Easiest way to import all functionality