Typechecking for own custom assignment


i created some inline-assignment very similar to NamedTupleComponentReference.

The NamedTupleComponentReference complains about type-missmatches between the value-Expression and the componentDeclaration. Where is that rule defined? I can't find it :-(



Comment actions Permalink

Hi Mirko,

Most likely it is typeof_NamedTupleLiteral rule.

I've found it by applying 'find node usages' to the 'value' link in NamedTupleComponentReference concept.

Best, Igor.

Comment actions Permalink

Hi Igor,

thanks for that. I found that rule too when i was digging around but i didn't realize that this could be the wanted ... for the first look

the second look after your posting tells me, that this one could be the code i was looking for...

but really not easy to understand... javadoc (f.e. for the methods in RulesFunctions_BaseLanguage) or other documentation here would be great!

Everyone who thinks the same is encouraged to vote for the documentation-feature-enhancements in  the issue-tracker ;-):






or others

btw.: can someone tell me, what the thing after ":==:" in "typeof(literal) :==: <(^( literal.tupleDeclaration )^)<*( PTYPES )*>>;"  in typeof_NamedTupleLiteral means and does?


Comment actions Permalink

Hi Mirko,

thanks for feedback, I've asked colleagues to review, especially MPS-4921 (doc on textGen).


<(^( literal.tupleDeclaration )^)<*( PTYPES )*>>

in left part of the type equation constructs instance of NamedTupleType concept using quotation/anti-quotation technique.

here we use quotation < ... > to create the instance:

< ( reference to tuple declaration ) < parameters > >

and reference anti-quotation  ^( ... )^ to parameterize reference to tuple declaration

and list anti-quotation *( ... )* to parameterize tuple parameters

see also user guide: http://www.jetbrains.net/confluence/display/MPS/Typesystem#Typesystem-quotations

The alternative would be to write code like:

node<NamedTupleType> ntt = new node<NamedTupleType>;

ntt.tupleDeclaration = literal.tupleDeclaration;


...  :==: ntt;

Regards, Igor.

Comment actions Permalink

Hi Mirko,

To find a type rule  that caused a certain type error you may use a Go To Rule Which Caused Type Error action in a popup menu shown over a highlighted cell, or rather by pressing ctrl-alt-mouse_left_click on the cell which shows you Type Error dialog, with a button Go To Rule in it.



Comment actions Permalink

Hi Cyril,

pretty cool functionality! This is a feature i was often looking for and actually i wanted to open a new thread on that soon ;-)

The "ctrl-alt-mouse_left_click" works perfect, but i can't get the popup-thing....

Following procedure:

1) write something type-wrong: string a = true;

2) cursor somewhere to the red-underlined "true"

2a) right-click-popup-menu doesn't show "Go To Rule Which Caused Type Error"

2b) "Go To"-Menu doesn't show "Go To Rule Which Caused Type Error"

Full selection of "true" didn't work out too...

i think the point is your "popup menu shown over a highlighted cell" ... the only thing i can find is "Highlight [Usages|Instance]" ... but no "Go To Rule Which Caused Type Error"

so where do i get that popup?



Comment actions Permalink

Hi Mirko, look into Typesystem submenu, I forgot I should have said that.

Regards, Cyril.


Please sign in to leave a comment.