/usr/share/acl2-6.5/books/regex/regex-parse.lisp is in acl2-books-source 6.5-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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; cert_param: (non-acl2r)
(include-book "regex-parse-bracket")
(include-book "regex-parse-brace")
(set-ignore-ok t)
(defun valid-repeat (reg)
(declare (xargs :guard (or (not reg)
(regex-p reg))))
(and reg
(pattern-match reg
((r-end) nil)
((r-begin) nil)
(& t))))
;; Each of these macros is for a construct that occurs in both
;; the basic and extended regexp parsers in exactly the same form
;; except for the name of the function in the recursive call.
;; Writing them as macros avoids repeating the code.
;; The variables str, prev1, prev2, opts, prev, and eprev
;; are defined in the calling function:
;; str - the string we're operating on
;; prev1 - the immediately preceding regexp; if the current character
;; is (or begins) a repetition operator, prev1 is what it
;; modifies
;; prev2 - the rest of the regexp that comes before prev1
;; prev - prev2 and prev1 (when they both exist) concatenated together;
;; prev1 alone if prev2 does not exist; nil if prev1 does not exist
;; eprev - prev2 and prev2 (when they both exist) concatenated together;
;; prev1 alone if prev2 does not exist; empty if prev1 does not exist
;; opts - parsing options
(defmacro parse-* (parsefun)
`(if (valid-repeat prev1)
(,parsefun str
(1+ idx)
(r-repeat prev1 0 -1)
prev2
brcount
opts)
;; If * is the first character in a subexpression
;; grep puts "any" as the inner regexp
(if (parse-options-strict-repeat opts)
(mv "* doesn't follow a repeating regex" idx brcount)
(,parsefun str
(1+ idx)
(r-repeat (r-any) 0 -1)
prev
brcount
opts))))
(defmacro parse-? (parsefun)
;; repeat 0 or 1 times
`(if (valid-repeat prev1)
(,parsefun str (1+ idx)
(r-repeat prev1 0 1)
prev2
brcount
opts)
(if (parse-options-strict-repeat opts)
(mv "? doesn't follow a regex" idx brcount)
(,parsefun str (1+ idx) (r-repeat (r-any) 0 1) prev brcount opts))))
(defmacro parse-+ (parsefun)
;; repeat one to infinity times
`(if (valid-repeat prev1)
(,parsefun str (1+ idx)
(r-repeat prev1 1 -1)
prev2
brcount
opts)
(if (parse-options-strict-repeat opts)
(mv "+ doesn't follow a regex" idx brcount)
(,parsefun str (1+ idx) (r-repeat (r-any) 1 -1) prev brcount opts))))
(defmacro parse-text (parsefun)
`(,parsefun str (1+ idx) (r-exact (char str idx)) prev brcount opts))
(defmacro parse-{ (parsefun)
;; Grep's behavior with malformed brace expressions is to treat the
;; braces as normal characters; this is our behavior when
;; parse-options-strict-brace is off. When on, we return an error.
;; When a brace begins a regexp (following a ^, $, (, or starting the pattern)
;; grep treats it as a repeated anychar; this is our behavior when
;; parse-options-strict-repeat is off. When on, if parse-options-strict-brace is off
;; we consider the brace to be text; otherwise we return an error.
`(let* ((valid (valid-repeat prev1))
(prevr (if valid
prev1
(r-any))))
(if (and (not valid)
(parse-options-strict-brace opts))
(if (parse-options-strict-repeat opts)
(mv "Brace expression has no operand" idx brcount)
(parse-text ,parsefun))
(mv-let (brace rest) (parse-brace str (1+ idx) prevr opts)
(if (stringp brace)
(if (parse-options-strict-brace opts)
(mv brace rest brcount) ;; error
(parse-text ,parsefun))
;; The parse was good and either prev1 is valid or
;; parse-options-strict-brace is not set so we use the brace parse.
(if (mbt (> rest idx))
(,parsefun str rest brace prev2 brcount opts)
(mv "impossible error" idx brcount)))))))
(defmacro parse-paren (parsefun)
;; Parse the inner expression, (xx check for the matching paren,)
;; then combine the resulting
;; regexes to form prev1, combine prev1 and 2 to form prev2,
;; and continue parsing.
;; Insert grouping symbol for use with backrefs.
`(mv-let (inner rem new-brcount)
(,parsefun str (1+ idx) nil nil (1+ brcount) opts)
(if (stringp inner) ;; catch error
(mv inner rem brcount)
(if (and (parse-options-strict-paren opts)
(or (string-index-end rem str)
(not (equal (char str rem) #\) ))))
;; Paren does not match and strict parens are on
(mv "Mismatched parens" idx new-brcount)
;; (if (or (equal (char str rem) #\) ) (not (parse-options-strict-paren opts)))
;; Paren matches or strict parens are not on
(if (string-index-end rem str)
(let ((idx rem))
(parse-end))
(if (mbt (> (1+ rem) idx))
(,parsefun str (1+ rem)
(r-group inner (1+ brcount))
prev
new-brcount
opts)
(mv "impossible error" idx new-brcount))))
)))
(defmacro parse-[ (parsefun)
`(mv-let (brac rest) (parse-bracket str (1+ idx))
(if (stringp brac)
(mv brac idx brcount)
(if (> rest idx)
(,parsefun str rest (r-charset brac) prev brcount opts)
(mv "impossible error: bracket" rest brcount)))))
(defmacro parse-disjunct (parsefun)
;; Concat prev1 and prev2, parse the rest, and
;; return the disjunction.
`(mv-let (regex rem brcount)
(,parsefun str (1+ idx) nil nil brcount opts)
(if (stringp regex) ;; catch error
(mv regex rem brcount)
(mv (r-disjunct eprev regex) rem brcount))))
(defmacro parse-backslash (parsefun elseaction)
;; In a context where the previous character in str is a backslash,
;; check whether the next character is a digit. If so insert a
;; backref; if not execute elseaction.
`(let ((idx (1+ idx)))
(if (string-index-end idx str)
(mv "Error: unfinished escape" idx brcount)
(let ((n (get-digit-char (char str idx))))
(if n
(,parsefun str (1+ idx) (r-backref n) prev brcount opts)
,elseaction)))))
(defmacro parse-$ (parsefun)
;; End of string
;; If this occurs in the middle of a concatenation it'll just fail;
;; we won't check if it occurs in an appropriate place for now.
`(,parsefun str (1+ idx) (r-end) prev brcount opts))
(defmacro parse-^ (parsefun)
;; Beginning of string
;; We'll allow it syntactically a lot of places where it'll just cause
;; unconditional failure.
`(,parsefun str (1+ idx) (r-begin) prev brcount opts))
(defmacro parse-. (parsefun)
;; Concat prev1 and prev2 and continue parsing with
;; prev1 as 'any.
`(,parsefun str (1+ idx) (r-any) prev brcount opts))
(defmacro parse-end ()
;; Concat prev1 and prev2 and return str as-is
;; so that the outer parser matches the paren.
;; The driver for this function should check the
;; second return value in order to catch extra right parens.
`(mv eprev idx brcount))
(defun ere-parse (str idx prev1 prev2 brcount opts)
(declare (xargs
:measure (string-index-measure idx str)
:guard (and (stringp str)
(natp idx)
(parse-opts-p opts)
(or (not prev1)
(regex-p prev1))
(or (not prev2)
(regex-p prev2))
(or (not prev2)
prev1)
(natp brcount))
:verify-guards nil
))
;; Set up correct bindings for the macro calls
(let* ((prev (if prev2
(r-concat prev2 prev1)
prev1))
(eprev (if prev prev (r-empty))))
(if (string-index-end idx str)
(parse-end)
(case (char str idx)
(#\$
(parse-$ ere-parse))
(#\^
(parse-^ ere-parse))
(#\*
(parse-* ere-parse))
(#\?
(parse-? ere-parse))
(#\+
(parse-+ ere-parse))
(#\[
(parse-[ ere-parse))
(#\{
(parse-{ ere-parse))
(#\(
(parse-paren ere-parse))
(#\|
(parse-disjunct ere-parse))
(#\.
(parse-. ere-parse))
(#\)
(parse-end))
(#\\
(parse-backslash
ere-parse
(parse-text ere-parse)))
(otherwise
(parse-text ere-parse))))))
(defthm ere-parse-integer
(implies (integerp idx)
(integerp (mv-nth 1 (ere-parse str idx prev1 prev2 brcount opts))))
:rule-classes (:rewrite :type-prescription))
(defthm ere-parse-index
(implies (and (stringp str)
(indexp idx str))
(<= (mv-nth 1 (ere-parse str idx prev1 prev2 brcount opts))
(length str)))
:rule-classes (:rewrite :linear)
:hints (("Goal" :in-theory (disable length))))
(defthm ere-parse-rest-len
(implies (integerp idx)
(<= idx
(mv-nth 1 (ere-parse str idx prev1 prev2 brcount opts))))
:rule-classes (:rewrite :linear))
(defthm ere-parse-brcount-increasing
(<= brcount (mv-nth 2 (ere-parse str idx prev1 prev2 brcount opts)))
:rule-classes (:rewrite :linear))
(defthm ere-parse-brcount-integer
(implies (integerp brcount)
(integerp (mv-nth 2 (ere-parse str idx prev1 prev2 brcount opts))))
:rule-classes (:rewrite :type-prescription))
(defthm ere-parse-regex
(implies (and (force (and (stringp str)
(natp idx)
(parse-opts-p opts)
(or (not prev1)
(regex-p prev1))
(or (not prev2)
(regex-p prev2))
(or (not prev2)
prev1)
(integerp brcount)
(<= 0 brcount)))
(case-split (not (stringp
(mv-nth 0 (ere-parse
str idx prev1 prev2 brcount opts))))))
(regex-p (mv-nth 0 (ere-parse str idx prev1 prev2 brcount opts))))
:rule-classes
(:rewrite
(:forward-chaining
:trigger-terms ((mv-nth 0 (ere-parse str idx prev1 prev2 brcount opts))))))
(defthm ere-parse-nonnil
(mv-nth 0 (ere-parse str idx prev1 prev2 brcount opts))
:hints (("Goal" :in-theory (disable ere-parse-regex))))
(verify-guards ere-parse :otf-flg t)
(defun bre-parse (str idx prev1 prev2 brcount opts)
(declare (xargs
:measure (string-index-measure idx str)
:guard (and (stringp str)
(natp idx)
(parse-opts-p opts)
(or (not prev1)
(regex-p prev1))
(or (not prev2)
(regex-p prev2))
(or (not prev2)
prev1)
(natp brcount))
:verify-guards nil
))
;; Set up correct bindings for the macro calls
(let* ((prev (if prev2
(r-concat prev2 prev1)
prev1))
(eprev (if prev prev (r-empty))))
(if (string-index-end idx str)
(parse-end)
(case (char str idx)
(#\*
(parse-* bre-parse))
(#\[
(parse-[ bre-parse))
(#\$
(parse-$ bre-parse))
(#\^
(parse-^ bre-parse))
(#\.
(parse-. bre-parse))
(#\\
(parse-backslash
bre-parse
(case (char str idx)
(#\?
(parse-? bre-parse))
(#\+
(parse-+ bre-parse))
(#\{
(parse-{ bre-parse))
(#\(
(parse-paren bre-parse))
(#\|
(parse-disjunct bre-parse))
(#\)
(parse-end))
(otherwise
(parse-text bre-parse)))))
(otherwise
(parse-text bre-parse))))))
(defthm bre-parse-integer
(implies (integerp idx)
(integerp (mv-nth 1 (bre-parse str idx prev1 prev2 brcount opts))))
:rule-classes (:rewrite :type-prescription))
(defthm bre-parse-index
(implies (and (stringp str)
(indexp idx str))
(<= (mv-nth 1 (bre-parse str idx prev1 prev2 brcount opts))
(length str)))
:rule-classes (:rewrite :linear)
:hints (("Goal" :in-theory (disable length))
("Subgoal *1/11" :expand (:free (prev1 prev2)
(bre-parse str idx nil prev2 brcount opts)))))
(defthm bre-parse-rest-len
(implies (integerp idx)
(<= idx
(mv-nth 1 (bre-parse str idx prev1 prev2 brcount opts))))
:rule-classes (:rewrite :linear))
(defthm bre-parse-brcount-increasing
(<= brcount (mv-nth 2 (bre-parse str idx prev1 prev2 brcount opts)))
:rule-classes (:rewrite :linear))
(defthm bre-parse-brcount-integer
(implies (integerp brcount)
(integerp (mv-nth 2 (bre-parse str idx prev1 prev2 brcount opts))))
:rule-classes (:rewrite :type-prescription))
(defthm bre-parse-regex
(implies (and (force (and (stringp str)
(natp idx)
(parse-opts-p opts)
(or (not prev1)
(regex-p prev1))
(or (not prev2)
(regex-p prev2))
(or (not prev2)
prev1)
(integerp brcount)
(<= 0 brcount)))
(case-split (not (stringp
(mv-nth 0 (bre-parse
str idx prev1 prev2 brcount opts))))))
(regex-p (mv-nth 0 (bre-parse str idx prev1 prev2 brcount opts))))
:rule-classes
(:rewrite
(:forward-chaining
:trigger-terms ((mv-nth 0 (bre-parse str idx prev1 prev2 brcount opts))))))
(defthm bre-parse-nonnil
(mv-nth 0 (bre-parse str idx prev1 prev2 brcount opts))
:hints (("Goal" :in-theory (disable bre-parse-regex))))
(verify-guards bre-parse :otf-flg t)
(defun fixed-string-parse (str idx prev1 prev2 brcount opts)
(declare (xargs
:measure (string-index-measure idx str)
:guard (and (stringp str)
(natp idx)
(parse-opts-p opts)
(or (not prev1)
(regex-p prev1))
(or (not prev2)
(regex-p prev2))
(or (not prev2)
prev1)
(natp brcount))
:verify-guards nil
))
;; Set up correct bindings for the macro calls
(let* ((prev (if prev2
(r-concat prev2 prev1)
prev1))
(eprev (if prev prev (r-empty))))
(if (string-index-end idx str)
(parse-end)
(parse-text fixed-string-parse))))
(defthm fixed-string-parse-integer
(implies (integerp idx)
(integerp (mv-nth 1 (fixed-string-parse str idx prev1 prev2 brcount opts))))
:rule-classes (:rewrite :type-prescription))
(defthm fixed-string-parse-index
(implies (and (stringp str)
(indexp idx str))
(<= (mv-nth 1 (fixed-string-parse str idx prev1 prev2 brcount opts))
(length str)))
:rule-classes (:rewrite :linear)
:hints (("Goal" :in-theory (disable length))))
(defthm fixed-string-parse-rest-len
(implies (integerp idx)
(<= idx
(mv-nth 1 (fixed-string-parse str idx prev1 prev2 brcount opts))))
:rule-classes (:rewrite :linear))
(defthm fixed-string-parse-brcount-increasing
(<= brcount (mv-nth 2 (fixed-string-parse str idx prev1 prev2 brcount opts)))
:rule-classes (:rewrite :linear))
(defthm fixed-string-parse-brcount-integer
(implies (integerp brcount)
(integerp (mv-nth 2 (fixed-string-parse str idx prev1 prev2 brcount opts))))
:rule-classes (:rewrite :type-prescription))
(defthm fixed-string-parse-regex
(implies (and (force (and (stringp str)
(natp idx)
(parse-opts-p opts)
(or (not prev1)
(regex-p prev1))
(or (not prev2)
(regex-p prev2))
(or (not prev2)
prev1)
(integerp brcount)
(<= 0 brcount)))
(case-split (not (stringp
(mv-nth 0 (fixed-string-parse
str idx prev1 prev2 brcount opts))))))
(regex-p (mv-nth 0 (fixed-string-parse str idx prev1 prev2 brcount opts))))
:rule-classes
(:rewrite
(:forward-chaining
:trigger-terms ((mv-nth 0 (fixed-string-parse str idx prev1 prev2 brcount opts))))))
(defthm fixed-string-parse-nonnil
(mv-nth 0 (fixed-string-parse str idx prev1 prev2 brcount opts))
:hints (("Goal" :in-theory (disable fixed-string-parse-regex))))
(verify-guards fixed-string-parse :otf-flg t)
(defun append-concats (left right)
(declare (xargs :guard (and (regex-p left)
(regex-p right))))
(if (r-concat-p left)
(r-concat (r-concat-left left)
(append-concats (r-concat-right left) right))
(r-concat left right)))
(defun post-parse-optimize (regex)
;; Recursively descend, consolidating repeats when possible.
;; This gets rid of the worst problems associated with multiple repeats;
;; a further solution is to remove duplicats when running repeats.
;; Also right-associate concats.
(declare (xargs :guard (regex-p regex)
:verify-guards nil
:measure (acl2-count regex)))
(pattern-match
regex
((r-concat left right)
(let ((left (post-parse-optimize left))
(right (post-parse-optimize right)))
(append-concats left right)))
((r-disjunct left right)
(r-disjunct
(post-parse-optimize left)
(post-parse-optimize right)))
((r-group reg n)
(r-group (post-parse-optimize reg) n))
((r-repeat reg min max)
(let ((inner (post-parse-optimize reg)))
(pattern-match
inner
((r-repeat inreg inmin inmax)
(<= inmin 1)
(r-repeat
inreg
(* min inmin)
(if (or (< max 0) (< inmax 0))
-1
(* max inmax))))
(& (r-repeat inner min max)))))
(& regex)))
(local (defthm integerp-*
(implies (and (integerp a)
(integerp b))
(integerp (* a b)))))
(defthm post-parse-optimize-regex-p
(implies (force (regex-p regex))
(regex-p (post-parse-optimize regex)))
:rule-classes
(:rewrite
(:forward-chaining :trigger-terms ((post-parse-optimize regex)))))
(local (defthm integerp-rationalp
(implies (integerp x)
(rationalp x))))
(verify-guards post-parse-optimize)
(defun regex-do-parse (str opts)
(declare (xargs :guard (and (stringp str)
(parse-opts-p opts))))
(mv-let (regex rest brefs)
(case (parse-options-type opts)
(ere
(ere-parse str 0 nil nil 0 opts))
(bre
(bre-parse str 0 nil nil 0 opts))
(fixed
(fixed-string-parse str 0 nil nil 0 opts))
(otherwise (mv "bad opts" nil nil)))
(declare (ignore brefs))
(if (and (not (string-index-end rest str))
(parse-options-strict-paren opts))
"EPAREN"
(if (stringp regex) regex
(post-parse-optimize regex)))))
(defthm regex-do-parse-type
(implies (and (force (and (stringp str)
(parse-opts-p opts)))
(case-split (not (stringp (regex-do-parse str opts)))))
(regex-p (regex-do-parse str opts))))
(in-theory (disable regex-do-parse))
|