hackerbase/src/util-parser.scm

102 lines
3.1 KiB
Scheme

;;
;; util-parser.scm
;;
;; Common parts of the parsers.
;;
;; ISC License
;;
;; Copyright 2023 Brmlab, z.s.
;; Dominik Pantůček <dominik.pantucek@trustica.cz>
;;
;; Permission to use, copy, modify, and/or distribute this software
;; for any purpose with or without fee is hereby granted, provided
;; that the above copyright notice and this permission notice appear
;; in all copies.
;;
;; THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
;; WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
;; WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
;; AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
;; CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
;; OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
;; NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
;; CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
;;
(declare (unit util-parser))
(module
util-parser
(
parser-preprocess-line
parser-parse-line
parser-tests!
)
(import scheme
(chicken base)
(chicken irregex)
testing)
;; Pass 0: Removes any comments and removes any leading and trailing
;; whitespace.
(define (parser-preprocess-line line)
(irregex-replace (irregex "[ \\t]*$" 'u)
(irregex-replace (irregex "^[ \\t]*" 'u)
(irregex-replace (irregex "#.*$" 'u) line "")
"")
""))
;; Pass 1: Expects line with comments and surrounding whitespace
;; removed, returns either #f if nothing was parsed, symbol if only
;; one token was there and pair of symbol and string if both key and
;; the value were present.
(define (parser-parse-line line)
(if (= (string-length line) 0)
#f
(let ((dm (irregex-search (irregex "[ \\t]" 'u) line)))
(if dm
(let* ((sep-idx (irregex-match-start-index dm))
(key-str (substring line 0 sep-idx))
(key (string->symbol key-str))
(sep+val (substring line sep-idx))
(val (irregex-replace (irregex "^[ \\t]*" 'u) sep+val "")))
(cons key val))
(string->symbol line)))))
;; Self-tests
(define (parser-tests!)
(run-tests
parser
(test-equal? parser-preprocess-line
(parser-preprocess-line "# all comment")
"")
(test-equal? parser-preprocess-line
(parser-preprocess-line " # all comment after spaces")
"")
(test-equal? parser-preprocess-line
(parser-preprocess-line " test # spaces and comment after spaces")
"test")
(test-equal? parser-preprocess-line
(parser-preprocess-line "key value # spaces and comment after spaces")
"key value")
(test-false parser-parse-line
(parser-parse-line ""))
(test-eq? parser-parse-line
(parser-parse-line "key")
'key)
(test-equal? parser-parse-line
(parser-parse-line "key value")
'(key . "value"))
(test-equal? parser-parse-line
(parser-parse-line "key value")
'(key . "value"))
(test-equal? parser-parse-line
(parser-parse-line "key value and some")
'(key . "value and some"))
(test-equal? parser-parse-line
(parser-parse-line "key value lot of spaces")
'(key . "value lot of spaces"))
))
)