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createProposals gets called twice within same context [message #1753412]

Mon, 06 February 2017 02:25

Eclipse User

Hello,

I'm trying to implement completion proposals based on datatypes within the language, so that it only suggests variables with the correct datatype.

I've got it to work but I've found that it still suggests other variables which don't match the given prefix.

After some fiddling I found out that the

createProposals

method gets called twice with the same context, one time with and one time without the prefix.

Simplified grammar:

grammar org.xtext.example.mydsl.MyDsl with org.eclipse.xtext.common.Terminals

generate myDsl "http://www.xtext.org/example/mydsl/MyDsl"

Model:
	variables+=Variable* statements+=Statement* calls+=StatementCall*;
	
Variable: 'let' name=ID;

StatementCall: statement=[Statement] '(' parameter+=[Variable]* ')';

Statement: 'Statement' name=ID '(' parameter+=Variable* ')';

terminal ID:
	'^'? ('a'..'z' | 'A'..'Z' | '-' | '$') ('a'..'z' | 'A'..'Z' | '-' | '0'..'9')*;

My proposalprovider:

/*
 * generated by Xtext 2.10.0
 */
package org.xtext.example.mydsl.ui.contentassist

import org.eclipse.xtext.ui.editor.contentassist.ContentAssistContext
import org.eclipse.xtext.ui.editor.contentassist.ICompletionProposalAcceptor

/**
 * See https://www.eclipse.org/Xtext/documentation/304_ide_concepts.html#content-assist
 * on how to customize the content assistant.
 */
class MyDslProposalProvider extends AbstractMyDslProposalProvider {
	
	override createProposals(ContentAssistContext context, ICompletionProposalAcceptor acceptor) {
		println('''curr: «context.currentModel» prev: «context.currentModel» prefix: «context.prefix»''')
		super.createProposals(context, acceptor)
	}
	
}

Test.mydsl:

let One
let $Two

Statement add(let x let y)

add(O)

When I'm hitting CTRL+SPACE after the

add(O

then the output is the following:

curr: org.xtext.example.mydsl.myDsl.impl.StatementCallImpl@6d0dcd4b prev: org.xtext.example.mydsl.myDsl.impl.StatementCallImpl@6d0dcd4b prefix: 
curr: org.xtext.example.mydsl.myDsl.impl.StatementCallImpl@6d0dcd4b prev: org.xtext.example.mydsl.myDsl.impl.StatementCallImpl@6d0dcd4b prefix: O

I expected the proposal to be called once only, because when I'm done filtering it does the same stuff without the prefix.

Expected proposals are:
One

What I got:
One
$Two

Does it have something to do with the $-prefix?

Re: createProposals gets called twice within same context [message #1753413 is a reply to message #1753412]

Mon, 06 February 2017 02:55

Eclipse User

Hi Markus,
what you have done is just modifying the very basic function which is called in multiple context.
usually, you just override a very special routine in the proposal provider which starts with "complete" like:

override completeMergefile_Name(EObject model, Assignment assignment, 
		ContentAssistContext context, ICompletionProposalAcceptor acceptor) {
		completeRuleCall(((assignment.getTerminal()as RuleCall)), context, acceptor);
		for (String fileId : LxtCore::getListFileIds) {
				acceptor.accept(createCompletionProposal(fileId , context))
		}
	}

[Updated on: Mon, 06 February 2017 02:56] by Moderator

Re: createProposals gets called twice within same context [message #1753414 is a reply to message #1753413]

Mon, 06 February 2017 03:09

Eclipse User

Hi Uli,

overriding the

createProposals

method was a hint that I got during a Xtext workshop.

However, using the specific overrides I still get the same results:

	override completeStatementCall_Parameter(EObject model, Assignment assignment, ContentAssistContext context, ICompletionProposalAcceptor acceptor) {
		println('''curr: «context.currentModel» prev: «context.currentModel» prefix: «context.prefix»''')
		super.completeStatementCall_Parameter(model, assignment, context, acceptor)
	}

Output:

curr: org.xtext.example.mydsl.myDsl.impl.StatementCallImpl@3baed0a9 prev: org.xtext.example.mydsl.myDsl.impl.StatementCallImpl@3baed0a9 prefix: O
curr: org.xtext.example.mydsl.myDsl.impl.StatementCallImpl@3baed0a9 prev: org.xtext.example.mydsl.myDsl.impl.StatementCallImpl@3baed0a9 prefix:

Re: createProposals gets called twice within same context [message #1754049 is a reply to message #1753414]

Tue, 14 February 2017 02:28

Eclipse User

Can anyone confirm that it might be a bug with the prefixer (not) handling the $ correctly?

Re: createProposals gets called twice within same context [message #1754051 is a reply to message #1754049]

Tue, 14 February 2017 02:44

Eclipse User

doesnt your grammar perfectly allow

add(x$)

which gives you two params x and $

so in your case if you have

add(x|
there could be a new var or the old var continued

?!?

since you have the $ you dont need a space to separate the params

add($$$) would be legit

=> it really depends on how you want to deal with this

Re: createProposals gets called twice within same context [message #1754065 is a reply to message #1754051]

Tue, 14 February 2017 05:05

Eclipse User

Oh right, the * in the ID was supposed to be a +.

I changed it to:

terminal ID:
	'^'? ('a'..'z' | 'A'..'Z' | '-' | '$') ('a'..'z' | 'A'..'Z' | '-' | '0'..'9')*;

However, the problem still persists.

The variable prefixed with a $ always shows up, no matter what I want to autocomplete (as if the prefix matcher always returns true).

I've recorded a gif to show you what I mean.

Attachment: 2017-02-14_11-02-49.gif
(Size: 70.06KB, Downloaded 114 times)

Re: createProposals gets called twice within same context [message #1754070 is a reply to message #1754065]

Tue, 14 February 2017 05:55

Eclipse User

terminal ID:
'^'? ('a'..'z' | 'A'..'Z' | '-' | '$') ('a'..'z' | 'A'..'Z' | '-' | '0'..'9')*;
still has no +

if i change it to + it works for me

Re: createProposals gets called twice within same context [message #1754087 is a reply to message #1754070]

Tue, 14 February 2017 07:58

Eclipse User

I copy-pasted it incorrectly Smile

The gif is done with the + instead of *.

I just confirmed it again.

if I type in varO and trigger completion it filters out varTwo and varThree correctly, but the variable with the $ sign is still in there

Re: createProposals gets called twice within same context [message #1754092 is a reply to message #1754087]

Tue, 14 February 2017 08:27

Eclipse User

can you please share you model

Re: createProposals gets called twice within same context [message #1754182 is a reply to message #1754092]

Wed, 15 February 2017 01:18

Eclipse User

Grammar:

grammar org.xtext.example.mydsl.MyDsl with org.eclipse.xtext.common.Terminals

generate myDsl "http://www.xtext.org/example/mydsl/MyDsl"


Model:
	variables+=Variable* statements+=Statement* calls+=StatementCall*;
	
Variable: 'let' name=ID;

StatementCall: statement=[Statement] '(' parameter+=[Variable]* ')';

Statement: 'Statement' name=ID '(' parameter+=Variable* ')';

terminal ID:
	'^'? ('a'..'z' | 'A'..'Z' | '-' | '$') ('a'..'z' | 'A'..'Z' | '-' | '0'..'9')+;

Test.mydsl:

let varOne
let varTwo
let varThree
let $somethingWithDollar

Statement add(let x let y)

add(

I've also attached the 2 files from the model directory of the core dsl project. I hope thats what you asked for Smile

Attachment: MyDsl.genmodel
(Size: 2.08KB, Downloaded 135 times)
Attachment: MyDsl.ecore
(Size: 1.65KB, Downloaded 135 times)

[Updated on: Wed, 15 February 2017 01:20] by Moderator

Re: createProposals gets called twice within same context [message #1754184 is a reply to message #1754182]

Wed, 15 February 2017 01:38

Eclipse User

still cannot reproduce. sure you regenerated the language? which xtext version do you use?

Re: createProposals gets called twice within same context [message #1754185 is a reply to message #1754184]

Wed, 15 February 2017 01:58

Eclipse User

I'm using 2.10 and regenerated.

Do you not get the variable with $ in every (filtered) proposal? Thats strange.

I just created a new project from scratch with the grammar, generated the language, startet runtime eclipse and the issue still persists.

Also I just noticed that the completion (as in insertion) of the proposal behaves differently (see attached gif).

I pushed the example to Github in case you have to look at generated stuff

Attachment: 2017-02-15_07-53-38.gif
(Size: 64.96KB, Downloaded 97 times)

Re: createProposals gets called twice within same context [message #1754189 is a reply to message #1754185]

Wed, 15 February 2017 02:23

Eclipse User

i am testing with 2.11

Re: createProposals gets called twice within same context [message #1754192 is a reply to message #1754189]

Wed, 15 February 2017 03:03

Eclipse User

strange, for me it behaves the same way with generating from 2.11 (again, completly new project)

What does work is pressing CTRL+SPACE first and then typing "var", the one with $ will disappear.

var<C-SPACE> still shows up the $ one and appends it on completion

Re: createProposals gets called twice within same context [message #1754201 is a reply to message #1754192]

Wed, 15 February 2017 04:28

Eclipse User

yes but that is still the very same problem

let varOne
let varTwo
let varThree
let var
let $somethingWithDollar

Statement add(let x let y)

add(var$somethingWithDollar)

is a legit model

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