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Add optimized split function that acts like python
Implement the equivalent of str.split in lisp. Optimized a bit for
speed: significantly faster than cl-ppcre or the serapeum equivalent.
fiddlerwoaroof authored on 05/04/2017 08:35:28Showing 1 changed files
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+(defpackage :string-utils |
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+ (:use :cl)) |
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+(in-package :string-utils) |
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+ |
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+(deftype array-length () |
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+ `(integer 0 ,array-dimension-limit)) |
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+(deftype array-index () |
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+ `(integer 0 ,(1- array-dimension-limit))) |
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+ |
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+(defun get-part-modifier (char string &optional count) |
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+ (declare (optimize #+dev (debug 3) #-dev (speed 3)) |
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+ (type character char) |
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+ (type string string)) |
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+ (flet ((count-splits (string) |
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+ (declare (optimize (speed 3)) |
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+ (type simple-string string)) |
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+ (do* ((x (the array-length 0) (1+ x)) |
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+ (cur-char #1=(aref string x) #1#) |
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+ (result (the array-length 0) (if (char= cur-char char) |
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+ (1+ result) |
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+ result))) |
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+ ((= x (1- (length string))) (1+ result)) |
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+ (declare (type array-length result))))) |
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+ (typecase string |
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+ ((and string (not simple-string)) |
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+ (setf string (copy-seq string)))) |
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+ (unless count |
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+ (setf count (count-splits string)))) |
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+ (let ((parts (make-array count :initial-element nil :element-type '(or string null))) |
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+ (start-idx 0) |
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+ (target-spot 0)) |
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+ (prog1 parts |
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+ (dotimes (end-idx (length string)) |
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+ (when (typecase string |
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+ (simple-string (char= (aref string end-idx) char)) |
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+ (string (char= (aref string end-idx) char))) |
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+ (setf (aref parts target-spot) |
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+ (make-array (- end-idx start-idx) :displaced-to string :displaced-index-offset start-idx |
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+ :element-type 'character)) |
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+ (incf target-spot) |
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+ (setf start-idx (1+ end-idx)) |
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+ (when (= target-spot (1- count)) |
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+ (return)))) |
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+ (when (<= start-idx (length string)) |
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+ (setf (aref parts target-spot) |
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+ (make-array (- (length string) start-idx) |
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+ :displaced-to string :displaced-index-offset start-idx |
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+ :element-type 'character)))))) |
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+ |
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+;; TODO: implement test |
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+(defun %split-on-char (divider string &key count (test nil)) |
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+ (declare (optimize #+dev (debug 3) (speed 3) (space 2)) |
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+ (type (or null array-length) count) |
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+ (type (or null function symbol) test) |
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+ (type character divider) |
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+ (type string string)) |
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+ (typecase string |
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+ ((and string (not simple-string)) |
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+ (setf string (copy-seq string)))) |
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+ (check-type string simple-string) |
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+ |
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+ (flet ((count-splits (string) |
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+ (declare (optimize (speed 3)) |
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+ (type simple-string string)) |
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+ (do* ((x (the array-length 0) (1+ x)) |
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+ (cur-char #1=(aref string x) #1#) |
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+ (result (the array-length 0) (if (char= cur-char divider) |
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+ (1+ result) |
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+ result))) |
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+ ((= x (1- (length string))) (1+ result)) |
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+ (declare (type array-length result)))) |
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+ (find-pos (start-pos) |
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+ (declare (optimize (speed 3)) |
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+ (type array-index start-pos)) |
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+ (etypecase test |
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+ (function (position divider string :start start-pos :test test)) |
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+ (null (position divider string :start start-pos)) |
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+ (symbol (position divider string :start start-pos :test (symbol-function test)))))) |
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+ |
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+ (unless count |
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+ (setf count (count-splits string))) |
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+ |
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+ (check-type count array-length) |
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+ (let ((parts (make-array (1+ count) :fill-pointer 0)) |
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+ (start-pos (the fixnum 0))) |
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+ (declare (dynamic-extent start-pos)) |
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+ (prog1 parts |
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+ (loop |
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+ for end-pos = (find-pos start-pos) |
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+ while end-pos |
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+ for num-parts from 1 below count |
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+ do |
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+ (vector-push (subseq string start-pos end-pos) parts) |
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+ (setf start-pos (1+ end-pos)) |
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+ finally |
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+ (when (< start-pos (length string)) |
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+ (vector-push (subseq string start-pos) |
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+ parts))))))) |
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+ |
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+(defmacro twice (&body body) |
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+ `(progn ,@body |
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+ ,@body)) |
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+ |
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+ |
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+(defun %split-on-string (divider string &key count (test nil)) |
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+ (declare (optimize #+dev (debug 3) (speed 3)) |
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+ (type string divider string) |
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+ (type (or null function symbol) test) |
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+ (type (or null array-index) count)) |
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+ (flet ((%search (start-pos) |
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+ (declare (optimize (speed 3)) |
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+ (type array-index start-pos) |
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+ (inline)) |
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+ (typecase divider |
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+ (simple-string (typecase string |
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+ (simple-string (search divider string :start2 start-pos)) |
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+ (string (search divider string :start2 start-pos)))) |
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+ (string (search divider string :start2 start-pos)))) |
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+ (%search-with-test (start-pos test) |
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+ (declare (optimize (speed 3)) |
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+ (type array-index start-pos) |
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+ (type function test) |
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+ (inline)) |
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+ (typecase divider |
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+ (simple-string (typecase string |
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+ (simple-string (search divider string :start2 start-pos :test test)) |
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+ (string (search divider string :start2 start-pos :test test)))) |
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+ (string (search divider string :start2 start-pos :test test))))) |
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+ (declare (dynamic-extent (function %search) |
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+ (function %search-with-test))) |
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+ (let ((num-parts (the array-length 0)) |
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+ (pattern-length (the array-length (length divider))) |
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+ (search-test (typecase test |
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+ (function test) |
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+ (null) |
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+ (symbol (symbol-function test)))) |
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+ (parts (make-array (if count count 100) |
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+ :adjustable t |
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+ :fill-pointer 0)) |
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+ (start-pos 0)) |
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+ (loop |
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+ for end-pos = (typecase search-test |
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+ (function (%search-with-test start-pos search-test)) |
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+ (null (%search start-pos))) |
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+ do |
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+ (vector-push-extend (subseq string start-pos end-pos) parts) |
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+ (incf (the array-length num-parts)) |
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+ while end-pos |
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+ do (setf start-pos (the array-length (+ pattern-length end-pos))) |
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+ until (and count (>= (1+ num-parts) count)) |
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+ finally |
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+ (when (and count end-pos) |
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+ (vector-push-extend (subseq string (+ pattern-length end-pos)) parts)) |
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+ (return parts))))) |
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+ |
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+(defun split (divider string &key count (test nil)) |
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+ (declare (optimize #+dev (debug 3) (speed 3) (space 3))) |
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+ (unless test |
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+ (setf test |
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+ (typecase divider |
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+ (string 'equal) |
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+ (t 'eql)))) |
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+ (etypecase divider |
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+ (character (%split-on-char divider string :count count :test test)) |
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+ (string (if (= 1 (length divider)) |
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+ (%split-on-char (aref divider 0) string :count count :test test) |
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+ (%split-on-string divider string :count count :test test))))) |