• Top
  • Documentation
  • Books
  • Recursion-and-induction
  • Boolean-reasoning
  • Projects
  • Debugging
  • Std
  • Proof-automation
  • Macro-libraries
  • ACL2
  • Interfacing-tools
    • Io
    • Defttag
    • Sys-call
    • Save-exec
    • Quicklisp
    • Oslib
    • Std/io
    • Bridge
    • Clex
      • Example-lexer
      • Sin
      • Matching-functions
        • Sin-match-until-lit
        • Sin-match-lit
        • Sin-match-charset*
        • Sin-match-some-lit
        • Sin-match-through-lit
        • Sin-match-everything
        • Def-match-thms
      • Def-sin-progress
    • Tshell
    • Unsound-eval
    • Hacker
    • Startup-banner
    • Command-line
  • Hardware-verification
  • Software-verification
  • Testing-utilities
  • Math

• Matching-functions

Sin-match-lit

Match exactly some particular string literal.

Signature

(sin-match-lit lit sin) → (mv match sin)

Arguments

lit — The literal string to search for.
    Guard (stringp lit).

sin — The sin stobj.

Returns

match — nil if no text was matched, or the matched text, i.e., lit itself.
    Type (or (stringp match) (not match)).

sin — The remainder of the input stream after removing the matched text, if applicable.

Examples:

(sin-match-lit "apple" [applesauce])
  -->
("apple" [sauce])

(sin-match-lit "apple" [candyapple])
  -->
(nil [candyapple])

Corner case: when lit is the empty string we always just fail. Matching the empty string would be quite degenerate, and failing in this case we can fit sin-match-lit into the ordinary matching-functions paradigm of progress, etc.

Definitions and Theorems

Function: sin-match-lit

(defun sin-match-lit (lit sin)
       (declare (xargs :stobjs (sin)))
       (declare (xargs :guard (stringp lit)))
       (let ((__function__ 'sin-match-lit))
            (declare (ignorable __function__))
            (b* (((when (or (mbe :logic (not (stringp lit))
                                 :exec nil)
                            (equal lit "")))
                  (mv nil sin))
                 ((unless (sin-matches-p lit sin))
                  (mv nil sin))
                 (sin (sin-nthcdr (length lit) sin)))
                (mv lit sin))))

Theorem: return-type-of-sin-match-lit.match

(defthm return-type-of-sin-match-lit.match
        (b* (((mv ?match ?sin)
              (sin-match-lit lit sin)))
            (or (stringp match) (not match)))
        :rule-classes :type-prescription)

Theorem: stringp-of-sin-match-lit.match

(defthm stringp-of-sin-match-lit.match
        (b* (((mv ?match ?new-sin)
              (sin-match-lit lit sin)))
            (equal (stringp match)
                   (if match t nil))))

Theorem: non-empty-of-sin-match-lit.match

(defthm non-empty-of-sin-match-lit.match
        (b* (((mv ?match ?new-sin)
              (sin-match-lit lit sin)))
            (equal (equal match "") nil)))

Theorem: sin-match-lit-progress-weak

(defthm sin-match-lit-progress-weak
        (b* (((mv ?match ?new-sin)
              (sin-match-lit lit sin)))
            (<= (len (strin-left new-sin))
                (len (strin-left sin))))
        :rule-classes ((:rewrite) (:linear)))

Theorem: sin-match-lit-progress-strong

(defthm sin-match-lit-progress-strong
        (b* (((mv ?match ?new-sin)
              (sin-match-lit lit sin)))
            (implies match
                     (< (len (strin-left new-sin))
                        (len (strin-left sin)))))
        :rule-classes ((:rewrite) (:linear)))

Theorem: sin-match-lit-reconstruction

(defthm sin-match-lit-reconstruction
        (b* (((mv ?match ?new-sin)
              (sin-match-lit lit sin)))
            (equal (append (explode match)
                           (strin-left new-sin))
                   (strin-left sin))))

Theorem: sin-match-lit-graceful-failure

(defthm sin-match-lit-graceful-failure
        (b* (((mv ?match ?new-sin)
              (sin-match-lit lit sin)))
            (implies (not match)
                     (equal new-sin sin))))

Theorem: sin-match-lit.match-when-ok

(defthm sin-match-lit.match-when-ok
        (b* (((mv ?match ?new-sin)
              (sin-match-lit lit sin)))
            (implies match (equal match lit))))

Theorem: equal-of-sin-match-lit-and-lit

(defthm equal-of-sin-match-lit-and-lit
        (b* (((mv ?match ?new-sin)
              (sin-match-lit lit sin)))
            (equal (equal match lit)
                   (if match
                       (and (stringp lit)
                            (consp (explode lit)))
                       (not lit)))))