Re: [ceylon-users] Is datasource a valid variable name?

[Gavin King]

The attribute of HikariDataSource you're trying to set is called
"dataSource", not "datasource". See the Javadoc here:

http://www.atetric.com/atetric/javadoc/com.zaxxer/HikariCP/2.4.2/com/zaxxer/hikari/HikariConfig.html#setDataSource-javax.sql.DataSource-

On Fri, Nov 4, 2016 at 5:09 AM, Mohammad Als <karim...@gmail.com> wrote:
> I'm using @bjansen's ceylon-Jooq example and found eclipse as well as
> IntelliJ reporting the following exceptions for the given method:
>
> object datasource extends HikariDataSource(){
> shared void setup(){
> value myds = PGSimpleDataSource();
> myds.databaseName = "sakila";
> myds.user = "postgres";
> myds.password = "postgres";
> myds.url = "jdbc:postgresql://localhost:5432/sakila";
> datasource = myds;
> }
> }
>
>
> Error:ceylon: toplevel value is neither variable nor late and may not be
> specified: 'datasource'
> Error:ceylon: cannot specify value from within its own body: 'datasource'
> Error:ceylon: specified expression must be assignable to declared type of
> 'datasource': 'PGSimpleDataSource' is not assignable to 'datasource'
>
>
> But when I change datasource to dataSource everything works fine. Why is
> ceylon reporting exception if the variable name is datasource (all
> lowercase)?
>
>
> Please help.
>
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--
Gavin King
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[Mohammad Als]

Well thanks for clarification. 

I've another question though: How is Ceylon differentiating between the object name and the variable name in the given code: 

Name of both the variable name defined in HikariDataSource and that of the object are  dataSource.

object dataSource extends HikariDataSource(){

    shared void setup(){
        value myds = PGSimpleDataSource();
        myds.databaseName = "sakila";
        myds.user = "postgres";
        myds.password = "postgres";
        myds.url = "jdbc:postgresql://localhost:5432/sakila";

        dataSource = myds;
    }

[Gavin King]

Well, by the scope. Members of the object hide things declared outside the object.

Sent from my iPhone

To view this discussion on the web visit https://groups.google.com/d/msgid/ceylon-users/a9344da3-e971-4e60-b857-9ef265d5da6a%40googlegroups.com.

[Mohammad Als]

Alright thanks... I'm now able to understand the scope concept using the given example:

class A(s){
    shared default String s;
}

object s extends A("S"){
    shared actual String s = "p";
}

What I'm still failing to understand is why there is no name collision for object s extends A("S") and shared actual String s = "p";

[Mohammad Als]

Alryt.. finally got it..:) A variable with the same name as object name can be defined in the object.

class A(){
    //shared default String s;
}

object s extends A(){
    shared String s = "p";
}

[Gavin King]

The name of the object "s" belongs to an outer scope. The name of the
member "s" belongs to an inner scope. Therefore no collision.

> https://groups.google.com/d/msgid/ceylon-users/4d9e48c0-f686-41b3-87ca-bcefa5ffb9ff%40googlegroups.com.