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Class type expected

This error means the current construct requires a class or class-like value, but the resolved type does not support the requested operation. The exact requirement depends on whether the script is accessing an imported class, a script class, a static member or a with statement.

Example​

This attempts to use with on a scalar value:

procedure ScriptEvent(var Value: Variant);
var
  Count: Integer;
begin
  with Count do // Error: Class type expected
    Value := 1;
end;

Use with only for a supported record or class value, or refer to the scalar directly:

Count := Count + 1;
Value := Count;

Contexts that emit the error​

The modified PascalScript compiler uses this diagnostic in several distinct paths:

  • An imported or external-class member/static operation requires an external class type (btExtClass).
  • A script-class type value or static call requires a script class type (btClass).
  • A with Expression do statement requires a record or a supported class value.

The wording is therefore slightly broader than its name suggests: the with parser accepts a record as well as a class. Conversely, a record does not satisfy the separate static/class-member paths.

How to diagnose it​

  1. Identify the construct at the reported position: a member access, class/static call or with statement.
  2. Find the Code Library page for the expression or type on the left side.
  3. Check whether that page documents a class instance, a class type, a record, a Variant or a scalar.
  4. For object members, confirm that an instance expression is used where an instance is required and a type name is used only for an exposed static member.
  5. Remove with and write the full qualified member access if the inferred owner is ambiguous.

Common causes​

  • Applying with to an integer, string, Boolean, array or unresolved Variant.
  • Treating a record type or record value as a class type for a static operation.
  • Calling an instance member through a class name, or a static member through an unrelated value.
  • Assuming every Delphi class is exposed to Velox scripts. Only registered Code Library types and members are available.
  • A preceding type error causing an expression to resolve differently from intended.

Location and follow-on messages​

Velox displays the parser position at which the required type check fails. That may be the do, a period/member token or the opening call rather than the declaration that gave the value its incorrect type. Correct the earliest type-related diagnostic first.

  • with — supported record/class owners and member-resolution risks.
  • Classes — types and members registered for Velox scripts.
  • Type mismatch — assigning or passing a value of an incompatible type.

External references​