Expr-value-option
Fixtype of optional expression values.
This is an option type introduced by fty::defoption.
Note that defoption is just a wrapper for fty::defflexsum, so there are :none and :some member
types, a case macro, and so forth.
Member Types
- :none → expr-value-option-none
- Represents that no expr-value-option is available, i.e., Nothing or None.
- :some → expr-value-option-some
- An available expr-value-option, i.e., Just val or Some val.
Theorem: not-errorp-when-expr-value-optionp
(defthm not-errorp-when-expr-value-optionp
(implies (expr-value-optionp x)
(not (errorp x))))
Subtopics
- Expr-value-option-fix
- Fixing function for expr-value-option structures.
- Expr-value-option-equiv
- Basic equivalence relation for expr-value-option structures.
- Expr-value-option-case
- Case macro for the different kinds of expr-value-option structures.
- Expr-value-option-some
- An available expr-value-option, i.e., Just val or Some val.
- Expr-value-option-none
- Represents that no expr-value-option is available, i.e., Nothing or None.
- Expr-value-optionp
- Recognizer for expr-value-option structures.
