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Error-checking

Ensure-value-is-symbol

Cause an error if a value is not a symbol.

Signature
(ensure-value-is-symbol x description error-erp error-val ctx state) → (mv erp val state)
Arguments: x — Value to check.; description — Guard (msgp description).; error-erp — Flag to return in case of error.; error-val — Value to return in case of error.; ctx — Context for errors.
Returns: erp — Type (implies erp (equal erp error-erp)).; val — Type (and (implies erp (equal val error-val)) (implies (and (not erp) error-erp) (not val))) .

Definitions and Theorems

Function: ensure-value-is-symbol

(defun ensure-value-is-symbol (x description
                                 error-erp error-val ctx state)
  (declare (xargs :stobjs (state)))
  (declare (xargs :guard (msgp description)))
  (b* (((unless (symbolp x))
        (er-soft+ ctx error-erp error-val
                  "~@0 must be a symbol, but it is ~x1 instead."
                  description x)))
    (value nil)))

Theorem: return-type-of-ensure-value-is-symbol.erp

(defthm return-type-of-ensure-value-is-symbol.erp
  (b* (((mv ?erp ?val ?state)
        (ensure-value-is-symbol x description
                                error-erp error-val ctx state)))
    (implies erp (equal erp error-erp)))
  :rule-classes :rewrite)

Theorem: return-type-of-ensure-value-is-symbol.val

(defthm return-type-of-ensure-value-is-symbol.val
  (b* (((mv ?erp ?val ?state)
        (ensure-value-is-symbol x description
                                error-erp error-val ctx state)))
    (and (implies erp (equal val error-val))
         (implies (and (not erp) error-erp)
                  (not val))))
  :rule-classes :rewrite)

Subtopics

Ensure-value-is-symbol$: Calls ensure-value-is-symbol with ctx and state as the last two arguments.