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;;; -*- Mode: LISP; Syntax: COMMON-LISP; Package: CL-PPCRE; Base: 10 -*-
;;; $Header: /usr/local/cvsrep/cl-ppcre/convert.lisp,v 1.57 2009/09/17 19:17:31 edi Exp $
;;; Here the parse tree is converted into its internal representation
;;; using REGEX objects. At the same time some optimizations are
;;; already applied.
;;; Copyright (c) 2002-2009, Dr. Edmund Weitz. All rights reserved.
;;; Redistribution and use in source and binary forms, with or without
;;; modification, are permitted provided that the following conditions
;;; are met:
;;; * Redistributions of source code must retain the above copyright
;;; notice, this list of conditions and the following disclaimer.
;;; * Redistributions in binary form must reproduce the above
;;; copyright notice, this list of conditions and the following
;;; disclaimer in the documentation and/or other materials
;;; provided with the distribution.
;;; THIS SOFTWARE IS PROVIDED BY THE AUTHOR 'AS IS' AND ANY EXPRESSED
;;; OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
;;; WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
;;; ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
;;; DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
;;; DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
;;; GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
;;; INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
;;; WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
;;; NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
;;; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
(in-package :cl-ppcre)
;;; The flags that represent the "ism" modifiers are always kept
;;; together in a three-element list. We use the following macros to
;;; access individual elements.
(defmacro case-insensitive-mode-p (flags)
"Accessor macro to extract the first flag out of a three-element flag list."
`(first ,flags))
(defmacro multi-line-mode-p (flags)
"Accessor macro to extract the second flag out of a three-element flag list."
`(second ,flags))
(defmacro single-line-mode-p (flags)
"Accessor macro to extract the third flag out of a three-element flag list."
`(third ,flags))
(defun set-flag (token)
"Reads a flag token and sets or unsets the corresponding entry in
the special FLAGS list."
(declare #.*standard-optimize-settings*)
(declare (special flags))
(case token
((:case-insensitive-p)
(setf (case-insensitive-mode-p flags) t))
((:case-sensitive-p)
(setf (case-insensitive-mode-p flags) nil))
((:multi-line-mode-p)
(setf (multi-line-mode-p flags) t))
((:not-multi-line-mode-p)
(setf (multi-line-mode-p flags) nil))
((:single-line-mode-p)
(setf (single-line-mode-p flags) t))
((:not-single-line-mode-p)
(setf (single-line-mode-p flags) nil))
(otherwise
(signal-syntax-error "Unknown flag token ~A." token))))
(defgeneric resolve-property (property)
(:documentation "Resolves PROPERTY to a unary character test
function. PROPERTY can either be a function designator or it can be a
string which is resolved using *PROPERTY-RESOLVER*.")
(:method ((property-name string))
(funcall *property-resolver* property-name))
(:method ((function-name symbol))
function-name)
(:method ((test-function function))
test-function))
(defun convert-char-class-to-test-function (list invertedp case-insensitive-p)
"Combines all items in LIST into test function and returns a
logical-OR combination of these functions. Items can be single
characters, character ranges like \(:RANGE #\\A #\\E), or special
character classes like :DIGIT-CLASS. Does the right thing with
respect to case-\(in)sensitivity as specified by the special variable
FLAGS."
(declare #.*standard-optimize-settings*)
(declare (special flags))
(let ((test-functions
(loop for item in list
collect (cond ((characterp item)
;; rebind so closure captures the right one
(let ((this-char item))
(lambda (char)
(declare (character char this-char))
(char= char this-char))))
((symbolp item)
(case item
((:digit-class) #'digit-char-p)
((:non-digit-class) (complement* #'digit-char-p))
((:whitespace-char-class) #'whitespacep)
((:non-whitespace-char-class) (complement* #'whitespacep))
((:word-char-class) #'word-char-p)
((:non-word-char-class) (complement* #'word-char-p))
(otherwise
(signal-syntax-error "Unknown symbol ~A in character class." item))))
((and (consp item)
(eq (first item) :property))
(resolve-property (second item)))
((and (consp item)
(eq (first item) :inverted-property))
(complement* (resolve-property (second item))))
((and (consp item)
(eq (first item) :range))
(let ((from (second item))
(to (third item)))
(when (char> from to)
(signal-syntax-error "Invalid range from ~S to ~S in char-class." from to))
(lambda (char)
(declare (character char from to))
(char<= from char to))))
(t (signal-syntax-error "Unknown item ~A in char-class list." item))))))
(unless test-functions
(signal-syntax-error "Empty character class."))
(cond ((cdr test-functions)
(cond ((and invertedp case-insensitive-p)
(lambda (char)
(declare (character char))
(loop with both-case-p = (both-case-p char)
with char-down = (if both-case-p (char-downcase char) char)
with char-up = (if both-case-p (char-upcase char) nil)
for test-function in test-functions
never (or (funcall test-function char-down)
(and char-up (funcall test-function char-up))))))
(case-insensitive-p
(lambda (char)
(declare (character char))
(loop with both-case-p = (both-case-p char)
with char-down = (if both-case-p (char-downcase char) char)
with char-up = (if both-case-p (char-upcase char) nil)
for test-function in test-functions
thereis (or (funcall test-function char-down)
(and char-up (funcall test-function char-up))))))
(invertedp
(lambda (char)
(loop for test-function in test-functions
never (funcall test-function char))))
(t
(lambda (char)
(loop for test-function in test-functions
thereis (funcall test-function char))))))
;; there's only one test-function
(t (let ((test-function (first test-functions)))
(cond ((and invertedp case-insensitive-p)
(lambda (char)
(declare (character char))
(not (or (funcall test-function (char-downcase char))
(and (both-case-p char)
(funcall test-function (char-upcase char)))))))
(case-insensitive-p
(lambda (char)
(declare (character char))
(or (funcall test-function (char-downcase char))
(and (both-case-p char)
(funcall test-function (char-upcase char))))))
(invertedp (complement* test-function))
(t test-function)))))))
(defun maybe-split-repetition (regex
greedyp
minimum
maximum
min-len
length
reg-seen)
"Splits a REPETITION object into a constant and a varying part if
applicable, i.e. something like
a{3,} -> a{3}a*
The arguments to this function correspond to the REPETITION slots of
the same name."
(declare #.*standard-optimize-settings*)
(declare (fixnum minimum)
(type (or fixnum null) maximum))
;; note the usage of COPY-REGEX here; we can't use the same REGEX
;; object in both REPETITIONS because they will have different
;; offsets
(when maximum
(when (zerop maximum)
;; trivial case: don't repeat at all
(return-from maybe-split-repetition
(make-instance 'void)))
(when (= 1 minimum maximum)
;; another trivial case: "repeat" exactly once
(return-from maybe-split-repetition
regex)))
;; first set up the constant part of the repetition
;; maybe that's all we need
(let ((constant-repetition (if (plusp minimum)
(make-instance 'repetition
:regex (copy-regex regex)
:greedyp greedyp
:minimum minimum
:maximum minimum
:min-len min-len
:len length
:contains-register-p reg-seen)
;; don't create garbage if minimum is 0
nil)))
(when (and maximum
(= maximum minimum))
(return-from maybe-split-repetition
;; no varying part needed because min = max
constant-repetition))
;; now construct the varying part
(let ((varying-repetition
(make-instance 'repetition
:regex regex
:greedyp greedyp
:minimum 0
:maximum (if maximum (- maximum minimum) nil)
:min-len min-len
:len length
:contains-register-p reg-seen)))
(cond ((zerop minimum)
;; min = 0, no constant part needed
varying-repetition)
((= 1 minimum)
;; min = 1, constant part needs no REPETITION wrapped around
(make-instance 'seq
:elements (list (copy-regex regex)
varying-repetition)))
(t
;; general case
(make-instance 'seq
:elements (list constant-repetition
varying-repetition)))))))
;; During the conversion of the parse tree we keep track of the start
;; of the parse tree in the special variable STARTS-WITH which'll
;; either hold a STR object or an EVERYTHING object. The latter is the
;; case if the regex starts with ".*" which implicitly anchors the
;; regex at the start (perhaps modulo #\Newline).
(defun maybe-accumulate (str)
"Accumulate STR into the special variable STARTS-WITH if
ACCUMULATE-START-P (also special) is true and STARTS-WITH is either
NIL or a STR object of the same case mode. Always returns NIL."
(declare #.*standard-optimize-settings*)
(declare (special accumulate-start-p starts-with))
(declare (ftype (function (t) fixnum) len))
(when accumulate-start-p
(etypecase starts-with
(str
;; STARTS-WITH already holds a STR, so we check if we can
;; concatenate
(cond ((eq (case-insensitive-p starts-with)
(case-insensitive-p str))
;; we modify STARTS-WITH in place
(setf (len starts-with)
(+ (len starts-with) (len str)))
;; note that we use SLOT-VALUE because the accessor
;; STR has a declared FTYPE which doesn't fit here
(adjust-array (slot-value starts-with 'str)
(len starts-with)
:fill-pointer t)
(setf (subseq (slot-value starts-with 'str)
(- (len starts-with) (len str)))
(str str)
;; STR objects that are parts of STARTS-WITH
;; always have their SKIP slot set to true
;; because the SCAN function will take care of
;; them, i.e. the matcher can ignore them
(skip str) t))
(t (setq accumulate-start-p nil))))
(null
;; STARTS-WITH is still empty, so we create a new STR object
(setf starts-with
(make-instance 'str
:str ""
:case-insensitive-p (case-insensitive-p str))
;; INITIALIZE-INSTANCE will coerce the STR to a simple
;; string, so we have to fill it afterwards
(slot-value starts-with 'str)
(make-array (len str)
:initial-contents (str str)
:element-type 'character
:fill-pointer t
:adjustable t)
(len starts-with)
(len str)
;; see remark about SKIP above
(skip str) t))
(everything
;; STARTS-WITH already holds an EVERYTHING object - we can't
;; concatenate
(setq accumulate-start-p nil))))
nil)
(declaim (inline convert-aux))
(defun convert-aux (parse-tree)
"Converts the parse tree PARSE-TREE into a REGEX object and returns
it. Will also
- split and optimize repetitions,
- accumulate strings or EVERYTHING objects into the special variable
STARTS-WITH,
- keep track of all registers seen in the special variable REG-NUM,
- keep track of all named registers seen in the special variable REG-NAMES
- keep track of the highest backreference seen in the special
variable MAX-BACK-REF,
- maintain and adher to the currently applicable modifiers in the special
variable FLAGS, and
- maybe even wash your car..."
(declare #.*standard-optimize-settings*)
(if (consp parse-tree)
(convert-compound-parse-tree (first parse-tree) parse-tree)
(convert-simple-parse-tree parse-tree)))
(defgeneric convert-compound-parse-tree (token parse-tree &key)
(declare #.*standard-optimize-settings*)
(:documentation "Helper function for CONVERT-AUX which converts
parse trees which are conses and dispatches on TOKEN which is the
first element of the parse tree.")
(:method ((token t) parse-tree &key)
(signal-syntax-error "Unknown token ~A in parse-tree." token)))
(defmethod convert-compound-parse-tree ((token (eql :sequence)) parse-tree &key)
"The case for parse trees like \(:SEQUENCE {<regex>}*)."
(declare #.*standard-optimize-settings*)
(cond ((cddr parse-tree)
;; this is essentially like
;; (MAPCAR 'CONVERT-AUX (REST PARSE-TREE))
;; but we don't cons a new list
(loop for parse-tree-rest on (rest parse-tree)
while parse-tree-rest
do (setf (car parse-tree-rest)
(convert-aux (car parse-tree-rest))))
(make-instance 'seq :elements (rest parse-tree)))
(t (convert-aux (second parse-tree)))))
(defmethod convert-compound-parse-tree ((token (eql :group)) parse-tree &key)
"The case for parse trees like \(:GROUP {<regex>}*).
This is a syntactical construct equivalent to :SEQUENCE intended to
keep the effect of modifiers local."
(declare #.*standard-optimize-settings*)
(declare (special flags))
;; make a local copy of FLAGS and shadow the global value while we
;; descend into the enclosed regexes
(let ((flags (copy-list flags)))
(declare (special flags))
(cond ((cddr parse-tree)
(loop for parse-tree-rest on (rest parse-tree)
while parse-tree-rest
do (setf (car parse-tree-rest)
(convert-aux (car parse-tree-rest))))
(make-instance 'seq :elements (rest parse-tree)))
(t (convert-aux (second parse-tree))))))
(defmethod convert-compound-parse-tree ((token (eql :alternation)) parse-tree &key)
"The case for \(:ALTERNATION {<regex>}*)."
(declare #.*standard-optimize-settings*)
(declare (special accumulate-start-p))
;; we must stop accumulating objects into STARTS-WITH once we reach
;; an alternation
(setq accumulate-start-p nil)
(loop for parse-tree-rest on (rest parse-tree)
while parse-tree-rest
do (setf (car parse-tree-rest)
(convert-aux (car parse-tree-rest))))
(make-instance 'alternation :choices (rest parse-tree)))
(defmethod convert-compound-parse-tree ((token (eql :branch)) parse-tree &key)
"The case for \(:BRANCH <test> <regex>).
Here, <test> must be look-ahead, look-behind or number; if <regex> is
an alternation it must have one or two choices."
(declare #.*standard-optimize-settings*)
(declare (special accumulate-start-p))
(setq accumulate-start-p nil)
(let* ((test-candidate (second parse-tree))
(test (cond ((numberp test-candidate)
(when (zerop (the fixnum test-candidate))
(signal-syntax-error "Register 0 doesn't exist: ~S." parse-tree))
(1- (the fixnum test-candidate)))
(t (convert-aux test-candidate))))
(alternations (convert-aux (third parse-tree))))
(when (and (not (numberp test))
(not (typep test 'lookahead))
(not (typep test 'lookbehind)))
(signal-syntax-error "Branch test must be look-ahead, look-behind or number: ~S." parse-tree))
(typecase alternations
(alternation
(case (length (choices alternations))
((0)
(signal-syntax-error "No choices in branch: ~S." parse-tree))
((1)
(make-instance 'branch
:test test
:then-regex (first
(choices alternations))))
((2)
(make-instance 'branch
:test test
:then-regex (first
(choices alternations))
:else-regex (second
(choices alternations))))
(otherwise
(signal-syntax-error "Too much choices in branch: ~S." parse-tree))))
(t
(make-instance 'branch
:test test
:then-regex alternations)))))
(defmethod convert-compound-parse-tree ((token (eql :positive-lookahead)) parse-tree &key)
"The case for \(:POSITIVE-LOOKAHEAD <regex>)."
(declare #.*standard-optimize-settings*)
(declare (special flags accumulate-start-p))
;; keep the effect of modifiers local to the enclosed regex and stop
;; accumulating into STARTS-WITH
(setq accumulate-start-p nil)
(let ((flags (copy-list flags)))
(declare (special flags))
(make-instance 'lookahead
:regex (convert-aux (second parse-tree))
:positivep t)))
(defmethod convert-compound-parse-tree ((token (eql :negative-lookahead)) parse-tree &key)
"The case for \(:NEGATIVE-LOOKAHEAD <regex>)."
(declare #.*standard-optimize-settings*)
;; do the same as for positive look-aheads and just switch afterwards
(let ((regex (convert-compound-parse-tree :positive-lookahead parse-tree)))
(setf (slot-value regex 'positivep) nil)
regex))
(defmethod convert-compound-parse-tree ((token (eql :positive-lookbehind)) parse-tree &key)
"The case for \(:POSITIVE-LOOKBEHIND <regex>)."
(declare #.*standard-optimize-settings*)
(declare (special flags accumulate-start-p))
;; keep the effect of modifiers local to the enclosed regex and stop
;; accumulating into STARTS-WITH
(setq accumulate-start-p nil)
(let* ((flags (copy-list flags))
(regex (convert-aux (second parse-tree)))
(len (regex-length regex)))
(declare (special flags))
;; lookbehind assertions must be of fixed length
(unless len
(signal-syntax-error "Variable length look-behind not implemented \(yet): ~S." parse-tree))
(make-instance 'lookbehind
:regex regex
:positivep t
:len len)))
(defmethod convert-compound-parse-tree ((token (eql :negative-lookbehind)) parse-tree &key)
"The case for \(:NEGATIVE-LOOKBEHIND <regex>)."
(declare #.*standard-optimize-settings*)
;; do the same as for positive look-behinds and just switch afterwards
(let ((regex (convert-compound-parse-tree :positive-lookbehind parse-tree)))
(setf (slot-value regex 'positivep) nil)
regex))
(defmethod convert-compound-parse-tree ((token (eql :greedy-repetition)) parse-tree &key (greedyp t))
"The case for \(:GREEDY-REPETITION|:NON-GREEDY-REPETITION <min> <max> <regex>).
This function is also used for the non-greedy case in which case it is
called with GREEDYP set to NIL as you would expect."
(declare #.*standard-optimize-settings*)
(declare (special accumulate-start-p starts-with))
;; remember the value of ACCUMULATE-START-P upon entering
(let ((local-accumulate-start-p accumulate-start-p))
(let ((minimum (second parse-tree))
(maximum (third parse-tree)))
(declare (fixnum minimum))
(declare (type (or null fixnum) maximum))
(unless (and maximum
(= 1 minimum maximum))
;; set ACCUMULATE-START-P to NIL for the rest of
;; the conversion because we can't continue to
;; accumulate inside as well as after a proper
;; repetition
(setq accumulate-start-p nil))
(let* (reg-seen
(regex (convert-aux (fourth parse-tree)))
(min-len (regex-min-length regex))
(length (regex-length regex)))
;; note that this declaration already applies to
;; the call to CONVERT-AUX above
(declare (special reg-seen))
(when (and local-accumulate-start-p
(not starts-with)
(zerop minimum)
(not maximum))
;; if this repetition is (equivalent to) ".*"
;; and if we're at the start of the regex we
;; remember it for ADVANCE-FN (see the SCAN
;; function)
(setq starts-with (everythingp regex)))
(if (or (not reg-seen)
(not greedyp)
(not length)
(zerop length)
(and maximum (= minimum maximum)))
;; the repetition doesn't enclose a register, or
;; it's not greedy, or we can't determine it's
;; (inner) length, or the length is zero, or the
;; number of repetitions is fixed; in all of
;; these cases we don't bother to optimize
(maybe-split-repetition regex
greedyp
minimum
maximum
min-len
length
reg-seen)
;; otherwise we make a transformation that looks
;; roughly like one of
;; <regex>* -> (?:<regex'>*<regex>)?
;; <regex>+ -> <regex'>*<regex>
;; where the trick is that as much as possible
;; registers from <regex> are removed in
;; <regex'>
(let* (reg-seen ; new instance for REMOVE-REGISTERS
(remove-registers-p t)
(inner-regex (remove-registers regex))
(inner-repetition
;; this is the "<regex'>" part
(maybe-split-repetition inner-regex
;; always greedy
t
;; reduce minimum by 1
;; unless it's already 0
(if (zerop minimum)
0
(1- minimum))
;; reduce maximum by 1
;; unless it's NIL
(and maximum
(1- maximum))
min-len
length
reg-seen))
(inner-seq
;; this is the "<regex'>*<regex>" part
(make-instance 'seq
:elements (list inner-repetition
regex))))
;; note that this declaration already applies
;; to the call to REMOVE-REGISTERS above
(declare (special remove-registers-p reg-seen))
;; wrap INNER-SEQ with a greedy
;; {0,1}-repetition (i.e. "?") if necessary
(if (plusp minimum)
inner-seq
(maybe-split-repetition inner-seq
t
0
1
min-len
nil
t))))))))
(defmethod convert-compound-parse-tree ((token (eql :non-greedy-repetition)) parse-tree &key)
"The case for \(:NON-GREEDY-REPETITION <min> <max> <regex>)."
(declare #.*standard-optimize-settings*)
;; just dispatch to the method above with GREEDYP explicitly set to NIL
(convert-compound-parse-tree :greedy-repetition parse-tree :greedyp nil))
(defmethod convert-compound-parse-tree ((token (eql :register)) parse-tree &key name)
"The case for \(:REGISTER <regex>). Also used for named registers
when NAME is not NIL."
(declare #.*standard-optimize-settings*)
(declare (special flags reg-num reg-names))
;; keep the effect of modifiers local to the enclosed regex; also,
;; assign the current value of REG-NUM to the corresponding slot of
;; the REGISTER object and increase this counter afterwards; for
;; named register update REG-NAMES and set the corresponding name
;; slot of the REGISTER object too
(let ((flags (copy-list flags))
(stored-reg-num reg-num))
(declare (special flags reg-seen named-reg-seen))
(setq reg-seen t)
(when name (setq named-reg-seen t))
(incf (the fixnum reg-num))
(push name reg-names)
(make-instance 'register
:regex (convert-aux (if name (third parse-tree) (second parse-tree)))
:num stored-reg-num
:name name)))
(defmethod convert-compound-parse-tree ((token (eql :named-register)) parse-tree &key)
"The case for \(:NAMED-REGISTER <regex>)."
(declare #.*standard-optimize-settings*)
;; call the method above and use the :NAME keyword argument
(convert-compound-parse-tree :register parse-tree :name (copy-seq (second parse-tree))))
(defmethod convert-compound-parse-tree ((token (eql :filter)) parse-tree &key)
"The case for \(:FILTER <function> &optional <length>)."
(declare #.*standard-optimize-settings*)
(declare (special accumulate-start-p))
;; stop accumulating into STARTS-WITH
(setq accumulate-start-p nil)
(make-instance 'filter
:fn (second parse-tree)
:len (third parse-tree)))
(defmethod convert-compound-parse-tree ((token (eql :standalone)) parse-tree &key)
"The case for \(:STANDALONE <regex>)."
(declare #.*standard-optimize-settings*)
(declare (special flags accumulate-start-p))
;; stop accumulating into STARTS-WITH
(setq accumulate-start-p nil)
;; keep the effect of modifiers local to the enclosed regex
(let ((flags (copy-list flags)))
(declare (special flags))
(make-instance 'standalone :regex (convert-aux (second parse-tree)))))
(defmethod convert-compound-parse-tree ((token (eql :back-reference)) parse-tree &key)
"The case for \(:BACK-REFERENCE <number>|<name>)."
(declare #.*standard-optimize-settings*)
(declare (special flags accumulate-start-p reg-num reg-names max-back-ref))
(let* ((backref-name (and (stringp (second parse-tree))
(second parse-tree)))
(referred-regs
(when backref-name
;; find which register corresponds to the given name
;; we have to deal with case where several registers share
;; the same name and collect their respective numbers
(loop for name in reg-names
for reg-index from 0
when (string= name backref-name)
;; NOTE: REG-NAMES stores register names in reversed
;; order REG-NUM contains number of (any) registers
;; seen so far; 1- will be done later
collect (- reg-num reg-index))))
;; store the register number for the simple case
(backref-number (or (first referred-regs) (second parse-tree))))
(declare (type (or fixnum null) backref-number))
(when (or (not (typep backref-number 'fixnum))
(<= backref-number 0))
(signal-syntax-error "Illegal back-reference: ~S." parse-tree))
;; stop accumulating into STARTS-WITH and increase MAX-BACK-REF if
;; necessary
(setq accumulate-start-p nil
max-back-ref (max (the fixnum max-back-ref)
backref-number))
(flet ((make-back-ref (backref-number)
(make-instance 'back-reference
;; we start counting from 0 internally
:num (1- backref-number)
:case-insensitive-p (case-insensitive-mode-p flags)
;; backref-name is NIL or string, safe to copy
:name (copy-seq backref-name))))
(cond
((cdr referred-regs)
;; several registers share the same name we will try to match
;; any of them, starting with the most recent first
;; alternation is used to accomplish matching
(make-instance 'alternation
:choices (loop
for reg-index in referred-regs
collect (make-back-ref reg-index))))
;; simple case - backref corresponds to only one register
(t
(make-back-ref backref-number))))))
(defmethod convert-compound-parse-tree ((token (eql :regex)) parse-tree &key)
"The case for \(:REGEX <string>)."
(declare #.*standard-optimize-settings*)
(convert-aux (parse-string (second parse-tree))))
(defmethod convert-compound-parse-tree ((token (eql :char-class)) parse-tree &key invertedp)
"The case for \(:CHAR-CLASS {<item>}*) where item is one of
- a character,
- a character range: \(:RANGE <char1> <char2>), or
- a special char class symbol like :DIGIT-CHAR-CLASS.
Also used for inverted char classes when INVERTEDP is true."
(declare #.*standard-optimize-settings*)
(declare (special flags accumulate-start-p))
(let ((test-function
(create-optimized-test-function
(convert-char-class-to-test-function (rest parse-tree)
invertedp
(case-insensitive-mode-p flags)))))
(setq accumulate-start-p nil)
(make-instance 'char-class :test-function test-function)))
(defmethod convert-compound-parse-tree ((token (eql :inverted-char-class)) parse-tree &key)
"The case for \(:INVERTED-CHAR-CLASS {<item>}*)."
(declare #.*standard-optimize-settings*)
;; just dispatch to the "real" method
(convert-compound-parse-tree :char-class parse-tree :invertedp t))
(defmethod convert-compound-parse-tree ((token (eql :property)) parse-tree &key)
"The case for \(:PROPERTY <name>) where <name> is a string."
(declare #.*standard-optimize-settings*)
(declare (special accumulate-start-p))
(setq accumulate-start-p nil)
(make-instance 'char-class :test-function (resolve-property (second parse-tree))))
(defmethod convert-compound-parse-tree ((token (eql :inverted-property)) parse-tree &key)
"The case for \(:INVERTED-PROPERTY <name>) where <name> is a string."
(declare #.*standard-optimize-settings*)
(declare (special accumulate-start-p))
(setq accumulate-start-p nil)
(make-instance 'char-class :test-function (complement* (resolve-property (second parse-tree)))))
(defmethod convert-compound-parse-tree ((token (eql :flags)) parse-tree &key)
"The case for \(:FLAGS {<flag>}*) where flag is a modifier symbol
like :CASE-INSENSITIVE-P."
(declare #.*standard-optimize-settings*)
;; set/unset the flags corresponding to the symbols
;; following :FLAGS
(mapc #'set-flag (rest parse-tree))
;; we're only interested in the side effect of
;; setting/unsetting the flags and turn this syntactical
;; construct into a VOID object which'll be optimized
;; away when creating the matcher
(make-instance 'void))
(defgeneric convert-simple-parse-tree (parse-tree)
(declare #.*standard-optimize-settings*)
(:documentation "Helper function for CONVERT-AUX which converts
parse trees which are atoms.")
(:method ((parse-tree (eql :void)))
(declare #.*standard-optimize-settings*)
(make-instance 'void))
(:method ((parse-tree (eql :word-boundary)))
(declare #.*standard-optimize-settings*)
(make-instance 'word-boundary :negatedp nil))
(:method ((parse-tree (eql :non-word-boundary)))
(declare #.*standard-optimize-settings*)
(make-instance 'word-boundary :negatedp t))
(:method ((parse-tree (eql :everything)))
(declare #.*standard-optimize-settings*)
(declare (special flags accumulate-start-p))
(setq accumulate-start-p nil)
(make-instance 'everything :single-line-p (single-line-mode-p flags)))
(:method ((parse-tree (eql :digit-class)))
(declare #.*standard-optimize-settings*)
(declare (special accumulate-start-p))
(setq accumulate-start-p nil)
(make-instance 'char-class :test-function #'digit-char-p))
(:method ((parse-tree (eql :word-char-class)))
(declare #.*standard-optimize-settings*)
(declare (special accumulate-start-p))
(setq accumulate-start-p nil)
(make-instance 'char-class :test-function #'word-char-p))
(:method ((parse-tree (eql :whitespace-char-class)))
(declare #.*standard-optimize-settings*)
(declare (special accumulate-start-p))
(setq accumulate-start-p nil)
(make-instance 'char-class :test-function #'whitespacep))
(:method ((parse-tree (eql :non-digit-class)))
(declare #.*standard-optimize-settings*)
(declare (special accumulate-start-p))
(setq accumulate-start-p nil)
(make-instance 'char-class :test-function (complement* #'digit-char-p)))
(:method ((parse-tree (eql :non-word-char-class)))
(declare #.*standard-optimize-settings*)
(declare (special accumulate-start-p))
(setq accumulate-start-p nil)
(make-instance 'char-class :test-function (complement* #'word-char-p)))
(:method ((parse-tree (eql :non-whitespace-char-class)))
(declare #.*standard-optimize-settings*)
(declare (special accumulate-start-p))
(setq accumulate-start-p nil)
(make-instance 'char-class :test-function (complement* #'whitespacep)))
(:method ((parse-tree (eql :start-anchor)))
;; Perl's "^"
(declare #.*standard-optimize-settings*)
(declare (special flags))
(make-instance 'anchor :startp t :multi-line-p (multi-line-mode-p flags)))
(:method ((parse-tree (eql :end-anchor)))
;; Perl's "$"
(declare #.*standard-optimize-settings*)
(declare (special flags))
(make-instance 'anchor :startp nil :multi-line-p (multi-line-mode-p flags)))
(:method ((parse-tree (eql :modeless-start-anchor)))
;; Perl's "\A"
(declare #.*standard-optimize-settings*)
(make-instance 'anchor :startp t))
(:method ((parse-tree (eql :modeless-end-anchor)))
;; Perl's "$\Z"
(declare #.*standard-optimize-settings*)
(make-instance 'anchor :startp nil))
(:method ((parse-tree (eql :modeless-end-anchor-no-newline)))
;; Perl's "$\z"
(declare #.*standard-optimize-settings*)
(make-instance 'anchor :startp nil :no-newline-p t))
(:method ((parse-tree (eql :case-insensitive-p)))
(declare #.*standard-optimize-settings*)
(set-flag parse-tree)
(make-instance 'void))
(:method ((parse-tree (eql :case-sensitive-p)))
(declare #.*standard-optimize-settings*)
(set-flag parse-tree)
(make-instance 'void))
(:method ((parse-tree (eql :multi-line-mode-p)))
(declare #.*standard-optimize-settings*)
(set-flag parse-tree)
(make-instance 'void))
(:method ((parse-tree (eql :not-multi-line-mode-p)))
(declare #.*standard-optimize-settings*)
(set-flag parse-tree)
(make-instance 'void))
(:method ((parse-tree (eql :single-line-mode-p)))
(declare #.*standard-optimize-settings*)
(set-flag parse-tree)
(make-instance 'void))
(:method ((parse-tree (eql :not-single-line-mode-p)))
(declare #.*standard-optimize-settings*)
(set-flag parse-tree)
(make-instance 'void)))
(defmethod convert-simple-parse-tree ((parse-tree string))
(declare #.*standard-optimize-settings*)
(declare (special flags))
;; turn strings into STR objects and try to accumulate into
;; STARTS-WITH
(let ((str (make-instance 'str
:str parse-tree
:case-insensitive-p (case-insensitive-mode-p flags))))
(maybe-accumulate str)
str))
(defmethod convert-simple-parse-tree ((parse-tree character))
(declare #.*standard-optimize-settings*)
;; dispatch to the method for strings
(convert-simple-parse-tree (string parse-tree)))
(defmethod convert-simple-parse-tree (parse-tree)
"The default method - check if there's a translation."
(declare #.*standard-optimize-settings*)
(let ((translation (and (symbolp parse-tree) (parse-tree-synonym parse-tree))))
(if translation
(convert-aux (copy-tree translation))
(signal-syntax-error "Unknown token ~A in parse tree." parse-tree))))
(defun convert (parse-tree)
"Converts the parse tree PARSE-TREE into an equivalent REGEX object
and returns three values: the REGEX object, the number of registers
seen and an object the regex starts with which is either a STR object
or an EVERYTHING object \(if the regex starts with something like
\".*\") or NIL."
(declare #.*standard-optimize-settings*)
;; this function basically just initializes the special variables
;; and then calls CONVERT-AUX to do all the work
(let* ((flags (list nil nil nil))
(reg-num 0)
reg-names
named-reg-seen
(accumulate-start-p t)
starts-with
(max-back-ref 0)
(converted-parse-tree (convert-aux parse-tree)))
(declare (special flags reg-num reg-names named-reg-seen
accumulate-start-p starts-with max-back-ref))
;; make sure we don't reference registers which aren't there
(when (> (the fixnum max-back-ref)
(the fixnum reg-num))
(signal-syntax-error "Backreference to register ~A which has not been defined." max-back-ref))
(when (typep starts-with 'str)
(setf (slot-value starts-with 'str)
(coerce (slot-value starts-with 'str)
#+:lispworks 'lw:simple-text-string
#-:lispworks 'simple-string)))
(values converted-parse-tree reg-num starts-with
;; we can't simply use *ALLOW-NAMED-REGISTERS*
;; since parse-tree syntax ignores it
(when named-reg-seen
(nreverse reg-names)))))
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