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Acre-internals

Parse-charset

Signature
(parse-charset x index) → (mv err pat new-index)
Arguments: x — Guard (stringp x).; index — Guard (natp index).
Returns: err — Type (acl2::maybe-stringp err).; pat — Type (implies (not err) (regex-p pat)).; new-index — Type (natp new-index).

Definitions and Theorems

Function: parse-charset

(defun parse-charset (x index)
  (declare (xargs :guard (and (stringp x) (natp index))))
  (let ((__function__ 'parse-charset))
    (declare (ignorable __function__))
    (b* ((x (lstrfix x))
         (index (lnfix index))
         ((when (<= (strlen x) index))
          (mv "String ended inside charset"
              nil index))
         ((mv negp index)
          (if (eql (char x index) #\^)
              (mv t (+ 1 index))
            (mv nil index)))
         ((when (<= (strlen x) index))
          (mv "String ended inside charset"
              nil index))
         ((mv err chars last-index)
          (parse-charset-aux x index))
         ((when err) (mv err nil last-index)))
      (mv nil
          (regex-charset (coerce chars 'string)
                         negp)
          last-index))))

Theorem: maybe-stringp-of-parse-charset.err

(defthm maybe-stringp-of-parse-charset.err
  (b* (((mv ?err ?pat ?new-index)
        (parse-charset x index)))
    (acl2::maybe-stringp err))
  :rule-classes :type-prescription)

Theorem: return-type-of-parse-charset.pat

(defthm return-type-of-parse-charset.pat
  (b* (((mv ?err ?pat ?new-index)
        (parse-charset x index)))
    (implies (not err) (regex-p pat)))
  :rule-classes :rewrite)

Theorem: natp-of-parse-charset.new-index

(defthm natp-of-parse-charset.new-index
  (b* (((mv ?err ?pat ?new-index)
        (parse-charset x index)))
    (natp new-index))
  :rule-classes :type-prescription)

Theorem: new-index-of-parse-charset

(defthm new-index-of-parse-charset
  (b* (((mv ?err ?pat ?new-index)
        (parse-charset x index)))
    (<= (nfix index) new-index))
  :rule-classes :linear)

Theorem: new-index-of-parse-charset-strong

(defthm new-index-of-parse-charset-strong
  (b* (((mv ?err ?pat ?new-index)
        (parse-charset x index)))
    (implies (not err)
             (< (nfix index) new-index)))
  :rule-classes :linear)

Theorem: new-index-of-parse-charset-less-than-length

(defthm new-index-of-parse-charset-less-than-length
  (b* (((mv ?err ?pat ?new-index)
        (parse-charset x index)))
    (implies (<= (nfix index)
                 (len (acl2::explode x)))
             (<= new-index (len (acl2::explode x)))))
  :rule-classes :linear)

Theorem: parse-charset-of-str-fix-x

(defthm parse-charset-of-str-fix-x
  (equal (parse-charset (acl2::str-fix x) index)
         (parse-charset x index)))

Theorem: parse-charset-streqv-congruence-on-x

(defthm parse-charset-streqv-congruence-on-x
  (implies (acl2::streqv x x-equiv)
           (equal (parse-charset x index)
                  (parse-charset x-equiv index)))
  :rule-classes :congruence)

Theorem: parse-charset-of-nfix-index

(defthm parse-charset-of-nfix-index
  (equal (parse-charset x (nfix index))
         (parse-charset x index)))

Theorem: parse-charset-nat-equiv-congruence-on-index

(defthm parse-charset-nat-equiv-congruence-on-index
  (implies (acl2::nat-equiv index index-equiv)
           (equal (parse-charset x index)
                  (parse-charset x index-equiv)))
  :rule-classes :congruence)