makehalt

Designates a halt state for the computational variant.

Syntax

makehalt(state);

Parameters

• state: The name of the state to mark as a halt state

Rules

• Only valid for the computational variant
• Not valid for other variants (use makeaccept/makereject instead)
• The state must be declared in makestates first
• Multiple halt states are allowed
• Unlike makeinit, there is no limit on the number of halt states

Behavior

When the machine enters a halt state, it stops execution. The computational variant doesn't distinguish between accept and reject - it simply halts.

Examples

setvariant(computational);
makestates(q0, q1, qhalt);
makeinit(q0);
makehalt(qhalt);

Multiple halt states:

setvariant(computational);
makestates(q0, q1, q2, qhalt1, qhalt2);
makeinit(q0);
makehalt(qhalt1);
makehalt(qhalt2);

Errors

• Wrong variant: 'makehalt' is only valid for the 'computational' variant — use 'makeaccept' or 'makereject'
• Undeclared state: state 'qhalt' is not declared

See Also

• makestates - Declare machine states
• makeinit - Designate the initial state
• makeaccept - Designate an accept state (non-computational)
• makereject - Designate a reject state (non-computational)