REBOL [ Title: "Mini-Calculator" Date: 6-Mar-2002 Version: 1.1.3 File: %mini-calc.r Author: "Ryan Cole" Purpose: "Tiny calculator example." Email: %ryancole--usa--com library: [ level: 'intermediate platform: none type: none domain: [math GUI] tested-under: none support: none license: none see-also: none ] ] reg: [] op: no do solve: does [ acc: none if op [error? try [acc: do reform [any [reg/2 acc 0] op 'to-decimal reg/1]]] reg: copy [] op: no ] calc: func [key] [ if find ".0123456789" key [ if none? pick reg not op [insert reg copy ""] if not all ["." = key find reg/1 key] [append reg/1 key] ] if find "+-*/" key [ if reg/2 [solve] any [reg/1 insert reg any [acc 0]] op: key ] if key = "=" [solve] ] view layout [ origin 0x0 space 0x0 across lcd: field "0." silver 140x22 right feel none return style k button 35x25 [ calc face/text if not find lcd/text: form any [reg/1 acc 0] "." [append lcd/text "."] show lcd ] k "7" k "8" k "9" k "/" return k "4" k "5" k "6" k "*" return k "1" k "2" k "3" k "-" return k "0" k "." k "=" k "+" ]