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Generating operation code Xtend/Xtend [message #822419]

Fri, 16 March 2012 11:44

Eclipse User

Hello, how can I generated and operation from this xtext models??

Expression :
TerminalExpression ({Operation.left=current}
op='+' right=Expression)?
;

TerminalExpression returns Expression:
'(' Expression ')' |
{IntLiteral} value=INT
;

I cant access to the parts...

I try this:

def declare(Expression elem){
''' «elem.left» '''

}

but there isnt a left atribute...

Any idea???

Thank you very much

Re: Generating operation code Xtend/Xtend [message #822439 is a reply to message #822419]

Fri, 16 March 2012 12:18

Eclipse User

Hi the subclass Operation has the left not Expression itself regards
Christian

Re: Generating operation code Xtend/Xtend [message #822512 is a reply to message #822419]

Fri, 16 March 2012 14:41

Eclipse User

Ok, but how can i get the operation object to get the left, the right and the op ???

Re: Generating operation code Xtend/Xtend [message #822527 is a reply to message #822512]

Fri, 16 March 2012 15:56

Eclipse User

Hi,

i do not understand your question. the grammar you gave leads to the following metamodel (you can always have a look at the ecore/generated java classes)

interface Expression {

}

interface Operation extends Expression {
left: Expression
right: Expression
op: String
}

interface IntLiteral extends Expression {
value: int
}

Re: Generating operation code Xtend/Xtend [message #822582 is a reply to message #822527]

Fri, 16 March 2012 20:47

Eclipse User

sorry, what i want is creating a function in xtend like this:

def declareExpression(Expression elem){

''' «elem.left.declareTerminalExpression» «elem.op» «elem.right.declareExpression» '''

}

to generate something like this:

1+2+4

but a I dont know how to get the operation object of an expression to make this. Because I need to get the left, the right and de op, fields to be able to print it.

The aim is generating this operation with ints, strings, booleans...

Like this:

(5+4)/20
(true&&false)&&true
"hello"+ "world"

Thanks for the help.

Re: Generating operation code Xtend/Xtend [message #822830 is a reply to message #822582]

Sat, 17 March 2012 06:24

Eclipse User

Hi

what would you do in java? you would do instance of checks and typecasts

variable instanceof Operation

variable as Operation

or you leverage extends dispatch methods

def dispatch declareExpression(Operation elem){

''' «elem.left.declareExpression» «elem.op» «elem.right.declareExpression» '''

}

def dispatch declareExpression(TerminalExpression elem){

''' «elem.value» '''

}

Re: Generating operation code Xtend/Xtend [message #824252 is a reply to message #822830]

Mon, 19 March 2012 08:45

Eclipse User

Hi, I am not able to do the second way:

This is my xtext file:

Model:
greetings+=Expression*;

Greeting:
'Hello' name=ID '!';

Expression :
TerminalExpression ({Operation.left=current}
op='+' right=Expression)?
;

TerminalExpression returns Expression:
'(' Expression ')' |
{IntLiteral} value=INT
;

And this is my xtend file:

/*
* generated by Xtext
*/
package org.xtext.example.mydsl.generator

import org.eclipse.emf.ecore.resource.Resource
import org.eclipse.xtext.generator.IGenerator
import org.eclipse.xtext.generator.IFileSystemAccess
import org.xtext.example.mydsl.myDsl.*

class MyDslGenerator implements IGenerator {

override void doGenerate(Resource resource, IFileSystemAccess fsa) {
fsa.generateFile(resource.className+".php", toTropoPHP(resource.contents.head as Model, resource))

}
def className(Resource res) {
var name = res.URI.lastSegment
return name.substring(0, name.indexOf('.'))
}

def toTropoPHP(Model sm, Resource resource) {

'''«FOR c : sm.greetings»«c.declareExpression»
«ENDFOR»'''
}

def dispatch declareExpression(Operation elem){

''' «elem.left.declareExpression» «elem.op» «elem.right.declareExpression» '''

}

def dispatch declareExpression(TerminalExpression elem){

''' «elem.value» '''

}

}

}

What am I doing bad???

Thanks a lot.

Re: Generating operation code Xtend/Xtend [message #824253 is a reply to message #824252]

Mon, 19 March 2012 08:46

Eclipse User

Sorry, the orange words are the errors that I get Smile