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Example-lexer

Lex*

Main lexer loop: completely tokenize the entire input stream.

Signature
(lex* sin) → (mv okp tokens sin)
Arguments: sin — The sin stobj.
Returns: okp — Did we lex everything successfully?.
Type (booleanp okp).; tokens — The tokens we've collected.
Type (tokenlist-p tokens).

Definitions and Theorems

Function: lex*

(defun lex* (sin)
  (declare (xargs :stobjs (sin)))
  (declare (xargs :guard t))
  (let ((__function__ 'lex*))
    (declare (ignorable __function__))
    (mbe :logic
         (b* (((when (sin-endp sin)) (mv t nil sin))
              ((mv tok1 sin) (lex1 sin))
              ((unless tok1) (mv nil nil sin))
              ((mv okp rest-tokens sin) (lex* sin))
              (ans (cons tok1 rest-tokens)))
           (mv okp ans sin))
         :exec
         (b* (((mv okp acc sin) (lex*-exec sin nil)))
           (mv okp (reverse acc) sin)))))

Theorem: booleanp-of-lex*.okp

(defthm booleanp-of-lex*.okp
  (b* (((mv ?okp ?tokens ?sin) (lex* sin)))
    (booleanp okp))
  :rule-classes :type-prescription)

Theorem: tokenlist-p-of-lex*.tokens

(defthm tokenlist-p-of-lex*.tokens
  (b* (((mv ?okp ?tokens ?sin) (lex* sin)))
    (tokenlist-p tokens))
  :rule-classes :rewrite)

Theorem: lex*-exec-removal

(defthm lex*-exec-removal
  (b* (((mv okp tokens new-sin) (lex* sin)))
    (equal (lex*-exec sin acc)
           (mv okp (revappend tokens acc)
               new-sin))))

Theorem: true-listp-of-lex*-tokens

(defthm true-listp-of-lex*-tokens
  (true-listp (mv-nth 1 (lex* sin)))
  :rule-classes :type-prescription)

Theorem: tokenlist-all-text-of-lex*

(defthm tokenlist-all-text-of-lex*
  (b* (((mv okp tokens ?new-sin) (lex* sin)))
    (implies okp
             (equal (tokenlist-all-text tokens)
                    (implode (strin-left sin))))))