With

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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. 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.

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 withdo has to be followed by exactly one statement. In practice this will always be a compound statement, though.

see also