View source for Diagrams/Dev/Migrate0.7

This page describes breaking API changes between diagrams 0.6 and 0.7, along with explanations of how to migrate to the new 0.7 API.

== <code>Diagrams.Coordinates</code> no longer exported by default ==

For better compatibility with <code>lens</code>, the <code>Diagrams.Coordinates</code> module (which contains, among other things, the <code>(&)</code> operator for constructing literal points and vectors) is no longer exported from <code>Diagrams.Prelude</code>.  You must now import <code>Diagrams.Coordinates</code> explicitly in order to make use of it.

== <code>CircleFrac</code> becomes <code>Turn</code> ==

<code>CircleFrac</code> has been renamed <code>Turn</code> (though <code>CircleFrac</code> is retained as a deprecated synonym).  This should really only affect you if you were using the <code>CircleFrac</code> constructor; use the new <code>Turn</code> constructor instead.

== Trail refactoring ==

The single biggest breaking change is a big fundamental refactoring in the way that segments and trails work.

* Segments can now be either "closed" or "open".  If you were directly dealing with segments before, you will now want to deal with "open" segments, which involves changing their type from (say) <code>Segment R2</code> to <code>Segment Closed R2</code>, and wrapping the final offset vector in an <code>OffsetClosed</code> constructor.

* <code>Path</code>s now contain <code>Located Trail</code>s instead of pairs of trails and points.  If you were explicitly constructing a <code>Path</code> from such pairs, instead use the <code>at</code> function to construct <code>Located Trail</code>s.

* The <code>PathLike</code> class has become the <code>TrailLike</code> class; the new <code>trailLike</code> function takes a <code>Located Trail</code> as an argument.

For more help with converting, see the user manual or ask for help in the #diagrams IRC channel on freenode.org.