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Choosing one of two numbers based on a condition

You already know to use the list selection [x,y][b] with a Boolean b for the ternary expression y if b else x. The variables x, y, and b can also be expressions, though note that both x and y are always evaluated unlike in the ternary.

Here's some potential optimizations when x and y are numbers.

• x=0 Use y*b
• x=1: Use y**b
• y=1: Use b or x
• y=x+1 (or y=x-1): Use x+b (or x-b)
• General explicit numbers x,y: Use x+z*b or y-z*b where z=y-x.

You can also switch x and y if you can rewrite b to be its negation instead.

Choosing one of two numbers based on a condition

You already know to use the list selection [x,y][b] with a Boolean b for the ternary expression y if b else x. The variables x, y, and b can also be expressions, though note that both x and y are evaluated even when not selected.

Here's some potential optimizations when x and y are numbers.

• [0,y][b] -> y*b
• [1,y][b] -> y**b
• [x,1][b] -> b or x
• [x,x+1][b] -> x+b 
• [x,x-1][b] -> x-b
• [1,-1][b] -> 1|-b
• [x,~x][b] -> x^-b
• [x,y][b] -> x+z*b (or y-z*b), where z=y-x.

You can also switch x and y if you can rewrite b to be its negation instead.

Choosing one of two numbers based on a condition

You already know to use the list selection [x,y][b] with a Boolean b for the ternary expression y if b else x. The variables x, y, and b can also be expressions, though note that both x and y are always evaluated unlike in the ternary.

Here's some potential optimizations when x and y are numbers.

• x=0 Use y*b
• x=1: Use y**b
• y=1: Use b or x
• y=x+1 (or y=x-1): Use x+b (or x-b)
• General explicit numbers x,y: Use x+z*b or y-z*b where z=y-x.

You can also switch x and y if you can rewrite b to be its negation instead.

Choosing one of two numbers based on a condition

You already know to use the list selection [x,y][b] with a Boolean b for the ternary expression y if b else x. The variables x, y, and b can also be expressions, though note that both x and y are always evaluated unlike in the ternary.

Here's some potential optimizations when x and y are numbers.

• x=0 Use y*b
• x=1: Use y**b
• y=1: Use b or x
• y=x+1 (or y=x-1): Use x+b (or x-b)
• General explicit numbers x,y: Use x+z*b or y-z*b where z=y-x.

You can also switch x and y if you can rewrite b to be its negation instead.

Choosing one of two numbers based on a condition

You already know to use the list selection [x,y][b] with a Boolean b for the ternary expression y if b else x. The variables x, y, and b can also be expressions, though note that both x and y are always evaluated unlike in the ternary.

Here's some potential optimizations when x and y are numbers.

• x=0 Use y*b
• x=1: Use y**b
• y=1: Use b or x
• y=x+1 (or y=x-1): Use x+b (or x-b)
• General explicit numbers x,y: Use x+z*b or y-z*b where z=y-x.

You can also switch x and y if you can rewrite b to be its negation instead.

Choosing one of two numbers based on a condition

You already know to use the list selection [x,y][b] with a Boolean b for the ternary expression y if b else x. The variables x, y, and b can also be expressions, though note that both x and y are always evaluated unlike in the ternary.

Here's some potential optimizations when x and y are numbers.

• x=0 Use y*b
• x=1: Use y**b
• y=1: Use b or x
• y=x+1 (or y=x-1): Use x+b (or x-b)
• General explicit numbers x,y: Use x+z*b or y-z*b where z=y-x.

You can also switch x and y if you can rewrite b to be its negation instead.