• Top
  • Documentation
  • Books
  • Boolean-reasoning
  • Projects
  • Debugging
  • Std
  • Proof-automation
  • Macro-libraries
  • ACL2
    • Theories
    • Rule-classes
    • Proof-builder
    • Recursion-and-induction
    • Hons-and-memoization
    • Events
    • Parallelism
    • History
    • Programming
    • Operational-semantics
    • Real
    • Start-here
    • Debugging
    • Miscellaneous
    • Output-controls
    • Macros
    • Interfacing-tools
      • Io
      • Defttag
      • Sys-call
      • Save-exec
      • Quicklisp
      • Std/io
        • Open-channel-lemmas
        • Std/io/read-char$
        • Std/io/read-object
        • Std/io/open-output-channel
        • Unsound-read
        • Read-string
        • Read-bytes$
          • Read-64ule
          • Read-64ube
          • Read-64sle
          • Read-64sbe
          • Read-32ule
          • Read-32sle
          • Read-32sbe
          • Read-32ube
          • Read-16sle
          • Read-16sbe
          • Read-16ule
          • Read-16ube
          • Read-8s
          • Combine-functions
        • File-measure
        • Read-bytes$-n
        • Std/io/read-byte$
        • Std/io/open-input-channel
        • Read-file-lines-no-newlines
        • Print-compressed
        • Nthcdr-bytes
        • Read-file-lines
        • Std/io/close-output-channel
        • Read-file-characters
        • Read-file-bytes
        • Print-legibly
        • Std/io/close-input-channel
        • Read-file-objects
        • Logical-story-of-io
        • Take-bytes
        • Std/io/peek-char$
        • Read-file-characters-rev
        • Read-file-as-string
        • Std/io/write-byte$
        • Std/io/set-serialize-character
        • Std/io/print-object$
        • Std/io/princ$
        • Std/io/read-file-into-string
        • *file-types*
      • Oslib
      • Bridge
      • Clex
      • Tshell
      • Unsound-eval
      • Hacker
      • ACL2s-interface
      • Startup-banner
      • Command-line
  • Interfacing-tools
    • Io
    • Defttag
    • Sys-call
    • Save-exec
    • Quicklisp
    • Std/io
      • Open-channel-lemmas
      • Std/io/read-char$
      • Std/io/read-object
      • Std/io/open-output-channel
      • Unsound-read
      • Read-string
      • Read-bytes$
        • Read-64ule
        • Read-64ube
        • Read-64sle
        • Read-64sbe
        • Read-32ule
        • Read-32sle
        • Read-32sbe
        • Read-32ube
        • Read-16sle
        • Read-16sbe
        • Read-16ule
        • Read-16ube
        • Read-8s
        • Combine-functions
      • File-measure
      • Read-bytes$-n
      • Std/io/read-byte$
      • Std/io/open-input-channel
      • Read-file-lines-no-newlines
      • Print-compressed
      • Nthcdr-bytes
      • Read-file-lines
      • Std/io/close-output-channel
      • Read-file-characters
      • Read-file-bytes
      • Print-legibly
      • Std/io/close-input-channel
      • Read-file-objects
      • Logical-story-of-io
      • Take-bytes
      • Std/io/peek-char$
      • Read-file-characters-rev
      • Read-file-as-string
      • Std/io/write-byte$
      • Std/io/set-serialize-character
      • Std/io/print-object$
      • Std/io/princ$
      • Std/io/read-file-into-string
      • *file-types*
    • Oslib
    • Bridge
    • Clex
    • Tshell
    • Unsound-eval
    • Hacker
    • ACL2s-interface
    • Startup-banner
    • Command-line
  • Hardware-verification
  • Software-verification
  • Math
  • Testing-utilities

• Read-bytes$

Read-8s

(read-8s channel state) reads a signed byte from the input channel.

Definitions and Theorems

Function: read-8s

(defun read-8s (channel state)
  (declare (xargs :guard (and (state-p state)
                              (symbolp channel)
                              (open-input-channel-p channel
                                                    :byte state))))
  (b* (((mv byte state)
        (read-byte$ channel state))
       ((unless byte) (mv nil state)))
    (mv (fast-logext 8 byte) state)))

Theorem: read-8s-signed-byte

(defthm read-8s-signed-byte
  (implies (and (mv-nth 0 (read-8s channel state))
                (force (state-p1 state))
                (force (open-input-channel-p1 channel
                                              :byte state))
                (force (symbolp channel)))
           (signed-byte-p 8 (mv-nth 0 (read-8s channel state)))))

Theorem: read-8s-integer

(defthm read-8s-integer
  (implies (mv-nth 0 (read-8s channel state))
           (integerp (mv-nth 0 (read-8s channel state)))))

Theorem: read-8s-range

(defthm read-8s-range
  (implies (and (mv-nth 0 (read-8s channel state))
                (force (state-p1 state))
                (force (open-input-channel-p1 channel
                                              :byte state))
                (force (symbolp channel)))
           (and (<= -128 (mv-nth 0 (read-8s channel state)))
                (<= (- (expt 2 7))
                    (mv-nth 0 (read-8s channel state)))
                (< (mv-nth 0 (read-8s channel state))
                   128)
                (< (mv-nth 0 (read-8s channel state))
                   (expt 2 7))))
  :rule-classes :linear)

Theorem: read-8s-state

(defthm read-8s-state
  (implies (and (force (state-p1 state))
                (force (open-input-channel-p1 channel
                                              :byte state))
                (force (symbolp channel)))
           (state-p1 (mv-nth 1 (read-8s channel state)))))

Theorem: read-8s-open-input-channel-p1

(defthm read-8s-open-input-channel-p1
 (implies
  (and (force (state-p1 state))
       (force (open-input-channel-p1 channel
                                     :byte state))
       (force (symbolp channel)))
  (open-input-channel-p1 channel
                         :byte (mv-nth 1 (read-8s channel state)))))