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authorPřemysl Janouch <p.janouch@gmail.com>2016-04-16 20:10:06 +0200
committerPřemysl Janouch <p.janouch@gmail.com>2016-04-16 20:11:11 +0200
commite97c60245c0c32537f58377031a1412699d56d28 (patch)
treeb8f1ec19d7080f8f595c72b56ecb8db5736a0de0 /plugins/zyklonb/calc
parent3a8d70de66bb38a7af7d6bb38f01f154ac413650 (diff)
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ZyklonB: add a calc plugin
Diffstat (limited to 'plugins/zyklonb/calc')
-rwxr-xr-xplugins/zyklonb/calc236
1 files changed, 236 insertions, 0 deletions
diff --git a/plugins/zyklonb/calc b/plugins/zyklonb/calc
new file mode 100755
index 0000000..e2f4be9
--- /dev/null
+++ b/plugins/zyklonb/calc
@@ -0,0 +1,236 @@
+#!/usr/bin/env guile
+
+ ZyklonB calc plugin, basic Scheme evaluator
+
+ Copyright 2016 Přemysl Janouch
+ See the file LICENSE for licensing information.
+
+!#
+
+(import (rnrs (6)))
+(use-modules ((rnrs) :version (6)))
+
+; --- Message parsing ----------------------------------------------------------
+
+(define-record-type message (fields prefix command params))
+(define (parse-message line)
+ (let f ([parts '()] [chars (string->list line)])
+ (define (take-word w chars)
+ (if (or (null? chars) (eqv? (car chars) #\x20))
+ (f (cons (list->string (reverse w)) parts)
+ (if (null? chars) chars (cdr chars)))
+ (take-word (cons (car chars) w) (cdr chars))))
+ (if (null? chars)
+ (let ([data (reverse parts)])
+ (when (< (length data) 2)
+ (error 'parse-message "invalid message"))
+ (make-message (car data) (cadr data) (cddr data)))
+ (if (null? parts)
+ (if (eqv? (car chars) #\:)
+ (take-word '() (cdr chars))
+ (f (cons #f parts) chars))
+ (if (eqv? (car chars) #\:)
+ (f (cons (list->string (cdr chars)) parts) '())
+ (take-word '() chars))))))
+
+; --- Utilities ----------------------------------------------------------------
+
+(define (display-exception e port)
+ (define (puts . x)
+ (for-all (lambda (a) (display a port)) x)
+ (newline port))
+
+ (define (record-fields rec)
+ (let* ([rtd (record-rtd rec)]
+ [v (record-type-field-names rtd)]
+ [len (vector-length v)])
+ (map (lambda (k i) (cons k ((record-accessor rtd i) rec)))
+ (vector->list v)
+ (let c ([i len] [ls '()])
+ (if (= i 0) ls (c (- i 1) (cons (- i 1) ls)))))))
+
+ (puts "Caught " (record-type-name (record-rtd e)))
+ (for-all
+ (lambda (subtype)
+ (puts " " (record-type-name (record-rtd subtype)))
+ (for-all
+ (lambda (field) (puts " " (car field) ": " (cdr field)))
+ (record-fields subtype)))
+ (simple-conditions e)))
+
+; XXX - we have to work around Guile's lack of proper eol-style support
+(define xc (make-transcoder (latin-1-codec) 'lf 'replace))
+(define irc-input-port (transcoded-port (standard-input-port) xc))
+(define irc-output-port (transcoded-port (standard-output-port) xc))
+
+(define (send . message)
+ (for-all (lambda (x) (display x irc-output-port)) message)
+ (display #\return irc-output-port)
+ (newline irc-output-port)
+ (flush-output-port irc-output-port))
+
+(define (get-line-crlf port)
+ (define line (get-line port))
+ (if (eof-object? line) line
+ (let ([len (string-length line)])
+ (if (and (> len 0) (eqv? (string-ref line (- len 1)) #\return))
+ (substring line 0 (- len 1)) line))))
+
+(define (get-config name)
+ (send "ZYKLONB get_config :" name)
+ (car (message-params (parse-message (get-line-crlf irc-input-port)))))
+
+(define (extract-nick prefix)
+ (do ([i 0 (+ i 1)] [len (string-length prefix)])
+ ([or (= i len) (char=? #\! (string-ref prefix i))]
+ [substring prefix 0 i])))
+
+(define (string-after s start)
+ (let ([s-len (string-length s)] [with-len (string-length start)])
+ (and (>= s-len with-len)
+ (string=? (substring s 0 with-len) start)
+ (substring s with-len))))
+
+; --- Calculator ---------------------------------------------------------------
+
+; Evaluator derived from the example in The Scheme Programming Language
+
+(define (env-new formals actuals env)
+ (cond [(null? formals) env]
+ [(symbol? formals) (cons (cons formals actuals) env)]
+ [else (cons (cons (car formals) (car actuals))
+ (env-new (cdr formals) (cdr actuals) env))]))
+(define (env-lookup var env) (cdr (assq var env)))
+(define (env-assign var val env) (set-cdr! (assq var env) val))
+
+(define (check-reductions r)
+ (if (= (car r) 0)
+ (error 'check-reductions "reduction limit exceeded")
+ (set-car! r (- (car r) 1))))
+
+; TODO - think about implementing more syntactical constructs
+(define (exec expr r env)
+ (check-reductions r)
+ (cond [(symbol? expr) (env-lookup expr env)]
+ [(pair? expr)
+ (case (car expr)
+ [(quote) (cadr expr)]
+ [(lambda) (lambda vals
+ (let ([env (env-new (cadr expr) vals env)])
+ (let loop ([exprs (cddr expr)])
+ (if (null? (cdr exprs))
+ (exec (car exprs) r env)
+ (begin (exec (car exprs) r env)
+ (loop (cdr exprs)))))))]
+ [(if) (if (exec (cadr expr) r env)
+ (exec (caddr expr) r env)
+ (exec (cadddr expr) r env))]
+ [(set!) (env-assign (cadr expr) (exec (caddr expr) r env) env)]
+ [else (apply (exec (car expr) r env)
+ (map (lambda (x) (exec x r env)) (cdr expr)))])]
+ [else expr]))
+
+(define-syntax forward
+ (syntax-rules ()
+ [(_) '()]
+ [(_ a b ...) (cons (cons (quote a) a) (forward b ...))]))
+
+(define base-library
+ (forward
+ ; Equivalence, procedure predicate, booleans
+ eqv? eq? equal? procedure? boolean? boolean=? not
+ ; numbers, numerical input and output
+ number? complex? real? rational? integer? exact? inexact? exact inexact
+ real-valued? rational-valued? integer-valued? number->string string->number
+ ; Arithmetic
+ = < > <= >= zero? positive? negative? odd? even? finite? infinite? nan?
+ min max + * - / abs div-and-mod div mod div0-and-mod0 div0 mod0
+ gcd lcm numerator denominator floor ceiling truncate round
+ rationalize exp log sin cos tan asin acos atan sqrt expt
+ make-rectangular make-polar real-part imag-part magnitude angle
+ ; Pairs and lists
+ map for-each cons car cdr caar cadr cdar cddr
+ caaar caadr cadar caddr cdaar cdadr cddar cdddr
+ caaaar caaadr caadar caaddr cadaar cadadr caddar cadddr
+ cdaaar cdaadr cdadar cdaddr cddaar cddadr cdddar cddddr
+ pair? null? list? list length append reverse list-tail list-ref
+ ; Symbols
+ symbol? symbol=? symbol->string string->symbol
+ ; Characters
+ char? char=? char<? char>? char<=? char>=? char->integer integer->char
+ ; Strings; XXX make-string can make an arbitrary length string -> removed
+ string? string=? string<? string>? string<=? string>=?
+ make-string string string-length string-ref substring
+ string-append string->list list->string string-for-each string-copy
+ ; Vectors; XXX make-vector can make an arbitrary length vectors -> removed
+ vector? make-vector vector vector-length vector-ref vector-set!
+ vector->list list->vector vector-fill! vector-map vector-for-each
+ ; Control features
+ apply call/cc values call-with-values dynamic-wind))
+(define extended-library
+ (forward
+ char-upcase char-downcase char-titlecase char-foldcase
+ char-ci=? char-ci<? char-ci>? char-ci<=? char-ci>=?
+ char-alphabetic? char-numeric? char-whitespace?
+ char-upper-case? char-lower-case? char-title-case?
+ string-upcase string-downcase string-titlecase string-foldcase
+ string-ci=? string-ci<? string-ci>? string-ci<=? string-ci>=?
+ find for-all exists filter partition fold-left fold-right
+ remp remove remv remq memp member memv memq assp assoc assv assq cons*
+ list-sort vector-sort vector-sort!
+ bitwise-not bitwise-and bitwise-ior bitwise-xor bitwise-if
+ bitwise-bit-count bitwise-length bitwise-first-bit-set bitwise-bit-set?
+ bitwise-copy-bit bitwise-bit-field bitwise-copy-bit-field
+ bitwise-arithmetic-shift bitwise-rotate-bit-field bitwise-reverse-bit-field
+ bitwise-arithmetic-shift-left bitwise-arithmetic-shift-right
+ set-car! set-cdr! string-set! string-fill!))
+(define (interpret expr)
+ (exec expr '(2000) (append base-library extended-library)))
+
+; We could show something a bit nicer but it would be quite Guile-specific
+(define (error-string e)
+ (map (lambda (x) (string-append " " (symbol->string x)))
+ (filter (lambda (x) (not (member x '(&who &message &irritants &guile))))
+ (map (lambda (x) (record-type-name (record-rtd x)))
+ (simple-conditions e)))))
+
+(define (calc input respond)
+ (define (stringify x)
+ (call-with-string-output-port (lambda (port) (write x port))))
+ (guard (e [else (display-exception e (current-error-port))
+ (apply respond "caught" (error-string e))])
+ (let* ([input (open-string-input-port input)]
+ [data (let loop ()
+ (define datum (get-datum input))
+ (if (eof-object? datum) '() (cons datum (loop))))])
+ (call-with-values
+ (lambda () (interpret (list (append '(lambda ()) data))))
+ (lambda message
+ (for-all (lambda (x) (respond (stringify x))) message))))))
+
+; --- Main loop ----------------------------------------------------------------
+
+(define prefix (get-config "prefix"))
+(send "ZYKLONB register")
+
+(define (process msg)
+ (when (string-ci=? (message-command msg) "PRIVMSG")
+ (let* ([nick (extract-nick (message-prefix msg))]
+ [target (car (message-params msg))]
+ [response-begin
+ (apply string-append "PRIVMSG "
+ (if (memv (string-ref target 0) (string->list "#&!+"))
+ `(,target " :" ,nick ": ") `(,nick " :")))]
+ [respond (lambda args (apply send response-begin args))]
+ [text (cadr (message-params msg))]
+ [input (or (string-after text (string-append prefix "calc "))
+ (string-after text (string-append prefix "= ")))])
+ (when input (calc input respond)))))
+
+(let main-loop ()
+ (define line (get-line-crlf irc-input-port))
+ (unless (eof-object? line)
+ (guard (e [else (display-exception e (current-error-port))])
+ (unless (string=? "" line)
+ (process (parse-message line))))
+ (main-loop)))