With

The reserved word with allows overriding the scope lookup routing for named scopes for the duration of one statement.

Routing

Identifiers are searched in the following order, until there is a hit:

1. current block
2. enclosing block, if any
3. the block enclosing the enclosing block, if any
4. … (and so on)
5. the most recently imported module, that means for instance the unit that appears at the end of the uses-clause list, if any
6. the penultimate module that has been imported, if any
7. … (and so on)
8. the first imported module, that means for instance the first unit appearing in a uses-clause, if any
9. additional automatically loaded units, for example, in a program if enabled, the heapTrc unit (see procedure loaddefaultunits in compiler/pmodules.pas for a full list)
10. the system unit (unless implicit inclusion has been disabled)

Override

The lookup order can be temporarily overridden with a with-clause. It looks like this:

    with namedScope do
    begin
        ???
    end;

This puts namedScope at the top of the routing. Identifiers are looked up in namedScope first, before other scopes are considered.

namedScope may be

• the name of a unit that has previously been imported via a uses-clause in the current section
• the name of a structured variable, that could have named members, i. e.
  • a record
  • object, or
  • class.

If multiple with-clauses ought to be nested, there is the short notation:

    with snakeOil, sharpTools do
    begin
        ???
    end;

which is equivalent to:

    with snakeOil do
    begin
        with sharpTools do
        begin
            ???
        end;
    end;

Note, begin-end are not part of the syntax, but with … do has to be followed by exactly one statement. In practice this will always be a compound statement, though.

See also

• namespaces

From the Free Pascal wiki, page "With", as it stood on 2021-12-06 after a change by Kai Burghardt, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's Licensing page. If you have concerns about this material, message the admin.