WIP: Kodi

content/kodi-na-scheme.md

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+Title: Kodi na Scheme
+Date: 2024-01-27 16:40
+Category: Programming
+Tags: linux, scheme, LambdaNative
+Lang: sw
+Slug: kodi-scheme
+Author: Benson Muite
+Summary: Tumia LambdaNative kutengeneza programu ya kuheasbu kodi
+
+# Mwanzo
+
+[LambdaNative](http://www.lambdanative.org/) inatumia
+[Gambit Scheme](https://gambitscheme.org) kusaidia
+mwandishi wa programu kuandika programu inaweza kutumikana kwa
+simu na kompyuta. Hapa, tutaonyesha mwandisho ya programu ndogo
+ya kusaidia mtu kufanya hesabu ya kodi ya Kenya. Maandiko hii
+ni zoezi tu, tafadhali soma sheria za Kenya kujua kodi unahitaji
+kulipa.
+
+# Programu ya kwanza
+
+Kuanza, ni nzuri kuandika programmu ndogo inaweza kutumikana
+kwa kiweko kya kompyuta.
+
+```
+#!/usr/bin/gsi-script
+
+
+(define relief 2400)
+(define (getshif x)
+ (* x 0.0275))
+(define (getnssf x)
+ (cond ((<= x 18000) (* 0.06 x))
+ (else 1080)))
+(define (getpaye x)
+ (cond ((<= x 0) 0)
+ ((<= x 24000) (* 0.1 x))
+ ((<= x 32334) (+ (* 0.25 (- x 24000)) 2400))
+ ((<= x 500000) (+ (* 0.30 (- x 32334)) 2083.5 2400))
+ ((<= x 800000) (+ (* 0.325 (- x 500000)) 140299.8 2083.5 2400))
+ (else (+ (* 0.35 (- x 800000)) 105000.0 140299.8 2083.5 2400))))
+
+(let ((monthly-salary (string->number (cadr (command-line)))))
+ (display "Kodi zako ni:")
+ (newline)
+ (let ((shif (getshif monthly-salary)))
+ (display "SHIF: ")
+ (display shif)
+ (newline)
+ (let ((nssf (getnssf monthly-salary)))
+ (display "NSSF: ")
+ (display nssf)
+ (newline)
+ (let ((taxable-salary 
+ (cond ((<= (- monthly-salary nhdf shif nssf relief) 0) 0)
+ (else (- monthly-salary nhdf shif nssf relief)))))
+ (display "Mshara unalipa PAYE: ")
+ (display taxable-salary)
+ (newline)
+ (let ((paye (getpaye taxable-salary)))
+ (display "PAYE: ")
+ (display paye)
+ (display "Mshahara mfukoni: ")
+ (display (- monthly-salary paye nhdf shif nssf))
+ (newline)))))))
+```
+
+Kutumia programu hii, sakinisha [Gambit Scheme](https://gambitscheme.org/latest/) kwa
+kompyuta yako. Hifadhi programu kwa faili inaitwa `kodi.scm`. Halafo kwa kiweko
+chapisha:
+```
+gsi-scheme kodi.scm 20000
+```
+Nambari ya mwisho ni mshahara inapatikana kila mwezi unataka kujua kodi.
+Scheme zingine zinaweza kutumikana pia, lakini, kuzitumia, badili laini za kichwa.
+Kwa mfano, ukitaka kutumia [Guile](https://www.gnu.org/software/guile/), tumia
+```
+#!/usr/bin/guile -s
+!#
+```
+kwa laini ya kwanza na ya pili. 
+
+## Tumia LambdaNative Kutengeneza Kiolesura cha Mtumiaji
+
+```
+;; Display variables
+(define gui #f)
+(define kodi-subdisplay1 #f)
+(define kodi-subdisplay2 #f)
+(define kodi-subdisplay3 #f)
+(define kodi-subdisplay4 #f)
+(define kodi-display #f)
+(define kodi-introdisplay #f)
+(define start-button #f)
+
+(define keypad `((
+ ( #\7 #\8 #\9 )
+ ( #\4 #\5 #\6 )
+ ( #\1 #\2 #\3 )
+ ( #\0 (#\h "Hesabu") (#\f "Futa"))
+)))
+
+;; State
+(define Hesabu #f)
+;; Tax relief
+(define relief 2400)
+(define paye 0)
+(define nssf 0)
+(define shif 0)
+(define mshahara-mfukoni 0)
+(define mshahara 0)
+
+;; Tax calculations
+(define (getshif x)
+ (* x 0.0275))
+(define (getnssf x)
+ (cond ((<= x 18000) (* 0.06 x))
+ (else 1080)))
+(define (getpaye x)
+ (cond ((<= x 0) 0)
+ ((<= x 24000) (* 0.1 x))
+ ((<= x 32334) (+ (* 0.25 (- x 24000)) 2400))
+ ((<= x 500000) (+ (* 0.30 (- x 32334)) 2083.5 2400))
+ ((<= x 800000) (+ (* 0.325 (- x 500000)) 140299.8 2083.5 2400))
+ (else (+ (* 0.35 (- x 800000)) 105000.0 140299.8 2083.5 2400))))
+
+;; Clear displays
+(define (kodi-futa)
+ (glgui-widget-set! gui kodi-subdisplay1 'label "")
+ (glgui-widget-set! gui kodi-subdisplay2 'label "")
+ (glgui-widget-set! gui kodi-subdisplay3 'label "")
+ (glgui-widget-set! gui kodi-subdisplay4 'label "")
+ (glgui-widget-set! gui kodi-display 'label "")
+ (set! Hesabu #f))
+
+;; Calculate taxes, check input is not void
+(define (kodi-hesabu)
+ (let* ((mshahara-str (glgui-widget-get gui kodi-display 'label))
+ (evalstr (string-append "\\" mshahara-str ";"))
+ (res (with-input-from-string evalstr (lambda ()
+ (with-exception-catcher (lambda (mshahara-str) #f) (lambda () (eval (read))))))))
+ (set! Hesabu (if (eq? res (void)) #f res))
+ (if Hesabu
+ (set! mshahara (string->number mshahara-str)))
+ (set! shif (getshif mshahara))
+ (set! nssf (getnssf mshahara))
+ (set! mshahara-wa-kodi
+ (cond ((<= (- mshahara shif nssf relief) 0) 0)
+ (else (- mshahara shif nssf relief))))
+ (set! paye (getpaye mshahara-wa-kodi))
+ (set! mshahara-mfukoni (- mshahara paye shif nssf))
+ (if Hesabu
+ (kodi-updatesub))
+ (set! Hesabu #f)))
+
+;; Display upto 2 decimal places
+(define (number->currency n)
+ (number->string (/ (round (* 100 n)) 100)))
+
+;; Update displays
+(define (kodi-updatesub)
+ (glgui-widget-set! gui kodi-subdisplay1 'label
+ (string-append "PAYE " (if Hesabu (number->currency paye) "")))
+ (glgui-widget-set! gui kodi-subdisplay2 'label
+ (string-append "NSSF " (if Hesabu (number->currency nssf) "")))
+ (glgui-widget-set! gui kodi-subdisplay3 'label
+ (string-append "SHIF " (if Hesabu (number->currency shif) "")))
+ (glgui-widget-set! gui kodi-subdisplay4 'label
+ (string-append "Pesa Mfukoni " (if Hesabu (number->currency mshahara-mfukoni) ""))))
+
+(main
+;; initialization
+ (lambda (w h)
+ (make-window 320 480)
+ (glgui-orientation-set! GUI_PORTRAIT)
+ (set! gui (make-glgui))
+ (let* ((w (glgui-width-get))
+ (h (glgui-height-get)))
+ (set! kodi-subdisplay1 (glgui-label gui 0 (- h 50) w 20 "" ascii_18.fnt LightBlue))
+ (glgui-widget-set! gui kodi-subdisplay1 'align GUI_ALIGNLEFT)
+ (glgui-widget-set! gui kodi-subdisplay1 'hidden #t)
+ (set! kodi-subdisplay2 (glgui-label gui 0 (- h 70) w 20 "" ascii_18.fnt Yellow))
+ (glgui-widget-set! gui kodi-subdisplay2 'align GUI_ALIGNLEFT)
+ (glgui-widget-set! gui kodi-subdisplay2 'hidden #t)
+ (set! kodi-subdisplay3 (glgui-label gui 0 (- h 90) w 20 "" ascii_18.fnt LightGreen))
+ (glgui-widget-set! gui kodi-subdisplay3 'align GUI_ALIGNLEFT)
+ (glgui-widget-set! gui kodi-subdisplay3 'hidden #t)
+ (set! kodi-subdisplay4 (glgui-label gui 0 (- h 110) w 20 "" ascii_24.fnt Orange))
+ (glgui-widget-set! gui kodi-subdisplay4 'align GUI_ALIGNLEFT)
+ (glgui-widget-set! gui kodi-subdisplay4 'hidden #t)
+ (set! kodi-introdisplay (glgui-label gui 5 (- h 80) (- w 10) 60 "Hesabu Kodi" ascii_32.fnt Green))
+ (glgui-widget-set! gui kodi-introdisplay 'align GUI_ALIGNCENTER)
+ (glgui-widget-set! gui kodi-introdisplay 'hidden #f)
+ (set! kodi-display (glgui-label gui 5 (- h 30) (- w 10) 0 "" ascii_32.fnt White))
+ (glgui-widget-set! gui kodi-display 'align GUI_ALIGNRIGHT)
+ (glgui-widget-set! gui kodi-display 'focus #t)
+ (glgui-widget-set! gui kodi-display 'hidden #t)
+ (set! start-button
+ (glgui-button-string gui (+ 5 (/ w 3) 5) (- h 44 150) 75 25 "ANZA" ascii_24.fnt
+ (lambda (g . x)
+ (glgui-widget-set! gui kodi-introdisplay 'hidden #t)
+ (glgui-widget-set! gui start-button 'hidden #t)
+ (glgui-widget-set! gui kodi-subdisplay1 'hidden #f)
+ (glgui-widget-set! gui kodi-subdisplay2 'hidden #f)
+ (glgui-widget-set! gui kodi-subdisplay3 'hidden #f)
+ (glgui-widget-set! gui kodi-subdisplay4 'hidden #f)
+ (glgui-widget-set! gui kodi-display 'hidden #f)
+ (let ((wgt (glgui-keypad gui 5 5 (- w 10) (- h 130 5) ascii_24.fnt keypad)))
+ (glgui-widget-set! gui wgt 'rounded #f)
+ (glgui-widget-set! gui wgt 'floatinghighlight #f)))))
+ (glgui-widget-set! gui start-button 'color Red)
+ ))
+
+;; events
+ (lambda (t x y)
+ (let ((skipevent #f))
+ (if (= t EVENT_KEYRELEASE)
+ (cond
+ ((= x EVENT_KEYESCAPE) (terminate))
+ ((= x (char->integer #\h)) (kodi-hesabu) (set! skipevent #t))
+ ((= x (char->integer #\f)) (kodi-futa) (set! skipevent #t))
+ ))
+ (if (not skipevent) (glgui-event gui t x y))))
+
+;; termination
+ (lambda () #t)
+;; suspend
+ (lambda () (glgui-suspend) (terminate))
+;; resume
+ (lambda () (glgui-resume))
+)
+
+;; eof
+
+```
+
+*Maandiko hizi zina leseni ya [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/)*
+*Programu zina leseni ya [GPL 3.0](https://www.gnu.org/licenses/gpl-3.0.txt)*