calculator.rye

fyne: context { 
    app: ?fyne-app 
    label: ?fyne-label
    entry: ?fyne-entry
    button: ?fyne-button
    container: ?fyne-container 
}

; If we create Fyne constructor function inside a fyne context

rye .needs { fyne }

do\in fyne { 
	cont: container 'vbox vals {
        container 'hbox vals {
            label "B:" :slot-b
            entry :value-b
        }

        container 'hbox vals {
            label "A:" :slot-a
            entry :value-a
        }

		container 'hbox vals {
            button "1" { value-a |get-text |to-string |concat "1" |set-text* value-a }
            button "2" { value-a |get-text |to-string |concat "2" |set-text* value-a }
            button "3" { value-a |get-text |to-string |concat "3" |set-text* value-a }
            button "/" { 
                value-b |get-text |to-string |to-integer :x
                value-a |get-text |to-string |to-integer :y
                x / y |to-string |set-text* value-a 

                value-b .set-text ""
            }
        }
        
        container 'hbox vals {
            button "4" { value-a |get-text |to-string |concat "4" |set-text* value-a }
            button "5" { value-a |get-text |to-string |concat "5" |set-text* value-a }
            button "6" { value-a |get-text |to-string |concat "6" |set-text* value-a }
            button "*" {
                value-b |get-text |to-string |to-integer :x
                value-a |get-text |to-string |to-integer :y
                x * y |to-string |set-text* value-a 

                value-b |set-text ""
            }
        }

        container 'hbox vals {
            button "7" { value-a |get-text |to-string |concat "7" |set-text* value-a }
            button "8" { value-a |get-text |to-string |concat "8" |set-text* value-a }
            button "9" { value-a |get-text |to-string |concat "9" |set-text* value-a }
            button "- " { 
                value-b |get-text |to-string |to-integer :x
                value-a |get-text |to-string |to-integer :y
                x - y |to-string |set-text* value-a 

                value-b |set-text ""
            }
        }

        container 'hbox vals {
            button "0" { value-a |get-text |to-string |concat "0" |set-text* value-a }
            button "=" { value-a |get-text |to-string |set-text* value-b value-a |set-text "" }
            button "~" { value-a |get-text |to-string :a 
                         value-b |get-text |to-string :b
                         value-a |set-text b
                         value-b |set-text a }
            button "+" { 
                value-b |get-text |to-string |to-integer :x
                value-a |get-text |to-string |to-integer :y
                x + y |to-string |set-text* value-a 

                value-b |set-text ""
            }
        }
	}

	app .new-window "Feedback"
	|set-content cont
	|show-and-run
}

Thank you for a great GUI example. I used all my rye knowledge and fixed a bug in between to make it a little nicer :), here:
https://gist.github.com/refaktor/63693faae0bea092da092f45920daaa9

Next step will be to add error handling. It will all be in github repo. Thanks!!