Combining pattern structure

This does not describe current behaviour - this is upcoming in version 1.0.0.

A core feature of Tidal is the ease in which two patterns can be combined. This is changing a lot in the upcoming 1.0.0 version of Tidal. For example, these are two patterns being combined by adding together their elements:

"2 3" + "4 5 6"

The two patterns line up over time like this:

  |  2  |  3  |
+ | 4 | 5 | 6 |

Unlike in previous versions of Tidal, by default the structure now comes from _both sides_. This means you end up with _four_ events, because the 5 lines up both with the 2 and the 3. So the result is equivalent to "6 [7 8] 9":

  |  2  |  3  |
+ | 4 | 5 | 6 |
= | 6 |7|8| 9 |

You can see that the event with the value of 4 fits in the event with value of 2, so you get a new event equalling their sum 6. You can see that the onset and duration is the interection, which in this case is just the onset and duration of the original event with the value 4.

Also see that the event with value 5 is cut in half, to create two, shorter events. Half matches with the 2 event and the other half matches with the 3 event. Again, the onset and duration of both events comes from the intersections.

The fourth and final event comes from the intersection of 3 and 6, giving a value of 9.

Structure from the left

The old behaviour was to take the structure from the left. You can still do this, but in this case using |+`. For example: <syntaxhighlight lang="Haskell"> "2 3" |+ "4 5 6"

In the above example, you end up with structure from the first, leftmost pattern, like this:

   |  2  |  3  |
|+ | 4 | 5 | 6 |
 = |  6  |  8  |

You can see the structure comes from the 2 and 3. 2 lines up with 4, and the start of 3 is in 5, so you end up with 2+4=6 and 3+5=8.

Structure from the right

Likewise, you can take the structure from the right, with +|. So "2 3" +| "4 5 6" looks like:

   |  2  |  3  |
+| | 4 | 5 | 6 |
 = | 6 | 7 | 9 |

All the operators

Note that + is actually an alias for |+|. So |+ is to take the structure from the left, +| from the right, and |+| or + for both. Here are all the basic operators you can use to combine structure:

Function	Both	Left	Right
Add	|+| (or +)	|+	+|
Subtract	|-| (or -)	|-	-|
Multiply	|*| (or *)	|*	*|
Divide	|/| (or /)	|/	/|
Modulo	|%|	|%	%|
Left values	|<|	|<	<|
Right values	|>|	|>	>|

The last two are interesting, they let you only take values from one side. So for example you could take structure from the left, but values from the right with |>, for example:

   |  2  |  3  |
|> | 4 | 5 | 6 |
 = |  4  |  5  |

This is very similar to how |+| used to work in the versions of tidal prior to 1.0.0 - it took structure from the left, but values from the right. Accordingly and # maintains this behaviour in the new tidal.