Method Overloading

[Mohammad Als]

I'm aware that Ceylon does not allow method overloading. But it is achievable using java.lang {overloaded } annotation.

import java.lang {
    ObjectArray,
    overloaded
}

shared abstract class AbstractOp<T>() of T given T satisfies AbstractOp<T> {
     /**
     * SQL FROM clause
     * @return Returns this object
     * @param table The table to use with FROM clause
     */
    shared overloaded default T from(Table table) {
    op().append(" FROM ");
    op().append(table.getTableName());
    return (this) of T;
  }

/**
 * SQL FROM clause.
 * @return Returns this object
 * @param tables The tables to use with FROM clause
 */
shared overloaded T from({Table*} tables) {
    value len = tables.size;
    variable Integer cnt = 1;
    op().append(" FROM(");
    for(table in tables){
        op().append(table.getTableName());
        if(cnt++ < len){
            op().append(",");
        }
    }
    op().append(")");
    return (this) of T;
  }
}

I've another class where I'm using overloaded annotation for static methods:
shared class ColumnValue {

    shared overloaded static ColumnValue setVal(Column column, Anything val) {
        if(!isValid(val)) {
            throw Exception("Invalid type passed for table column:``column`` ");
        }
        return ColumnValue(column,val);
    }

    shared overloaded static ColumnValue setVal(Anything val) {
        if(!isValid(val)) {
            throw Exception("Invalid value passed.");
        }
        return ColumnValue(Column(""),val);
    }

    Column column;
    Anything val;

    new(Column column, Anything val){
        this.column = column;
        this.val = val;
    }

    shared Anything getValue() => val;

    shared Column getColumn() => column;
}

Now, I'm trying to import the method "setVal" statically but it fails..."Illegal static import, setVal is not static"

However, it allows to use setVal if:

1) I call it using ColumnValue.setVal("Germany");
2) It allows static import if I remove the overloaded annotation and name the two methods differently as below:

shared class ColumnValue {

    shared static ColumnValue set(Column column, Anything val) {
        if(!isValid(val)) {
            throw Exception("Invalid type passed for table column:``column`` ");
        }
        return ColumnValue(column,val);
    }

    shared static ColumnValue setVal(Anything val) {
        if(!isValid(val)) {
            throw Exception("Invalid value passed.");
        }
        return ColumnValue(Column(""),val);
    }

    Column column;
    Anything val;

    new(Column column, Anything val){
        this.column = column;
        this.val = val;
    }

    shared Anything getValue() => val;

    shared Column getColumn() => column;
}

[Gavin King]

Hi, I just tried the following code, which compiled and executed
perfectly on but 1.3.3 and current git:


import java.lang {
overloaded
}

shared void run() {
Ceylon.foo("", 2);
Ceylon.foo(10);
Ceylon.foo(1.2);
Ceylon.foo("", 1.2);
}


class Ceylon {
shared static overloaded void foo(String s, Integer i) {
print("string, int");
}
shared static overloaded void foo(Integer i) {
print("int");
}
shared static overloaded void foo(Anything any) {
print("any");
}
shared static overloaded void foo(String s, Anything any) {
print("string, any");
}
shared new () {}
}

I really can't see what's different about your code.

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--
Gavin King
Red Hat
ga...@ceylon-lang.org
@1ovthafew

[Mohammad Als]

I want to know if foo() can be statically imported..?

import {

  Ceylon{

     foo

  }

}

Is this possible?

[Gavin King]

Oh, now I understand. OK, let me take a closer look.

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[Gavin King]

Fixed.

https://github.com/eclipse/ceylon/issues/7403

[Mohammad Als]

Thank you :)

[Gavin King]

Welcome.

Sent from my iPhone

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