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Forum: Epsilon

Topic: Visualising an expression grammar

Re: Visualising an expression grammar [message #1060709 is a reply to message #1059971]

Tue, 28 May 2013 03:26

Claudio Heeg
Messages: 57
Registered: April 2013

Member

Hello,

after a little work I managed to put up the important formulae in tree-form.
I did this by heavily annotating every function, i.e. every parameter of every function got a gmf.link() to show in the tree.
And that, as you might imagine, caused me to run into out-of-heapspace errors and the like and made it impossible to generate diagram code.

As, first of all, the tree view doesn't look all too nice and secondly is costly, I wonder if I could instead put at lease the Parameters of a proper, non-primitive function (i.e. everything except +-*/) into that function's compartment (or as that function's property)?
I did try gmf.compartment(foo="bar") on the parameters, but that didn't seem to work ("Called feature domainMetaElement on undefined object").

A snippet of the grammar look as following:

Function_Simple:
	Abs | Cos;

Abs:
	name='Abs''('add=Addition')';

Cos:
	name='Cos''('add=Addition')';

As you can see those functions can include additions by themselves, so the corresponding Emfatic file snippet looks as follows:

class Expression {
}

@gmf.node(label="name", phantom="true")
class Function_Simple extends Expression {
  attr String name;
  @gmf.compartment(foo="bar")		// that doesn't work, @gmf.link() does
  val Expression add;
}

class Abs extends Function_Simple {
}

class Cos extends Function_Simple {
}

Any help would, as always, be greatly appreciated.

// Edit:
Nevermind, I now transformed that graphic into a pure compartment model. The possibility of an outright mix seems unlikely.
However, putting function parameters into the model as property values still seems interesting.

And, another related question that arose: Instead of modeling the elements as "Abs, Cos, ...", can I just annotate them somehow to only make them "Function_Simple", and, again, have the function's name only as a property value?
It is the same with primitive functions - they'll show up as Addition, Multiplication, ... instead of as an Expression, which makes for poor ability to bidirectionally edit the diagram.

[Updated on: Tue, 28 May 2013 04:19]

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Current Time: Tue May 28 12:34:19 EDT 2013