Splitting a bill

Package: FINANCE_PACKAGE. Registered by createEngine(); for a slimmer engine, register it explicitly (see choosing packages).

Splitting a bill is the most common money note there is: an amount divided by the number of people paying it. split <amount> between <N>, or <amount> split <N> ways, answers it in place.

split $120 between 3 // $40.00 each
$120 split 3 ways // $40.00 each
split $100 between 4 people // $25.00 each

The amount stays exact, so a tip written as a percentage composes with the split on one line: $120 + 18% is $141.60, and split three ways that is $47.20 each. A bare number splits to a bare number, so no currency is invented where none was written.

$120 + 18% split 3 ways // $47.20 each
10 split 3 ways // 3.33 each

The boundary is the odd penny. split $100 between 3 is not a bare $33.33 each that quietly loses a penny: the extra penny is named, and the shares add back to the total to the cent.

split $100 between 3 // $33.33 each, with 1 share paying $33.34

The odd amount is the currency’s smallest one, its minor unit (see money precision). A yen has no subunit, so a yen bill is shared out in whole yen, and a Kuwaiti dinar is counted to the thousandth, so a dinar bill is shared to the fils.

¥100 split 3 ways // ¥33 each, with 1 share paying ¥34
split ¥1000 between 3 // ¥333 each, with 1 share paying ¥334
split 10 KWD between 3 // 3.333 KWD each, with 1 share paying 3.334 KWD

The amount can be a fraction of a sum, written as a fraction: 1/2 KWD is half a dinar, as it is on a line of its own, and it is shared to the fils as 0.5 KWD would be. A fraction that ends in base ten (a half, three eighths) is an exact amount; one that does not (a third) is its nearest decimal.

split 1/2 KWD between 3 // 0.166 KWD each, with 2 shares paying 0.167 KWD
split 3/8 KWD between 2 // 0.187 KWD each, with 1 share paying 0.188 KWD

split, ways and people are ordinary words everywhere else. They are read as the split grammar only inside the full shape, so a variable named split, or :split = 5, is untouched. The count must be a whole number of at least one, and a literal: a parenthesised or worded count leaves split an ordinary word.