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#### 10.9.1 Expression evaluation

This note provides a bit more detail for Java programmers on what is going on here; it describes how the use of functions in STILTS algebraic expressions relates to normal Java code.

The expressions which you write are compiled to Java bytecode when you enter them (if there is a 'compilation error' it will be reported straight away). The functions listed in the previous subsections are all the `public static` methods of the classes which are made available by default. The classes listed are all in the package `uk.ac.starlink.ttools.func`. However, the public static methods are all imported into an anonymous namespace for bytecode compilation, so that you write `sqrt(x,y)` and not `Maths.sqrt(x,y)`. The same happens to other classes that are imported (which can be in any package or none) - their public static methods all go into the anonymous namespace. Thus, method name clashes are a possibility.

This cleverness is all made possible by the rather wonderful JEL.

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STILTS - Starlink Tables Infrastructure Library Tool Set
Starlink User Note256
STILTS web page: http://www.starlink.ac.uk/stilts/
Author email: m.b.taylor@bristol.ac.uk
Mailing list: topcat-user@jiscmail.ac.uk