This is nice. Now I'm learning from you!
On Thursday, June 5, 2014, David Lambert <[email protected]> wrote:
> What would I do? I'd use this opportunity to practice adverbial
> programming. (Yes, thank you, I've learned from your answers to my tacit
> adverb questions.) I've changed your definition of clear so that y sets the
> initial stack, and of dup. All of the j stack manipulation verbs are
> monadic. Excepting clear, enter, and dupkip, they ignore y. To do: handle
> errors, write an interpreter, other.
>
> Stack =: 1 : ' ,.STACK =: ((STACK"_) :: (''''"_) 0) u y'
>
> NB. u Monad replaces top of stack with u TOS
> Monad =: (@:{:)(]`}:`,`)(`:6)~ Stack
>
> NB. u Dyad replaces top 2 items with the
> NB. result of inserting u between them.
> Dyad =: (/)(]`(_2&}.)`,`[:`)(`(_2&{.))(`:6)~ Stack
>
> clear =: ] Stack
> enter =: , Stack
> dupkip =: ([ , ({.~ -)) Stack
>
> rot3 =: ((_3 }. [) , _1 |. _3 {. [) Stack
>
> dup =: 2&# Monad
> reciprocal =: % Monad
> chs =: - Monad
>
> plus =: + Dyad
> minus =: - Dyad
> times =: * Dyad
> divide =: % Dyad
> exch =: ,~ Dyad
>
> clear'eta'
> e
> t
> a
> exch''
> e
> a
> t
> rot3''
> t
> e
> a
> enter'm'
> t
> e
> a
> m
>
>
> clear i.8
> 0
> 1
> 2
> 3
> 4
> 5
> 6
> 7
> reciprocal''
> 0
> 1
> 2
> 3
> 4
> 5
> 6
> 0.142857
> divide''
> 0
> 1
> 2
> 3
> 4
> 5
> 42
> square =: times@dup NB. or *: Monad
> square''
> 0
> 1
> 2
> 3
> 4
> 5
> 1764
>
> Date: Thu, 5 Jun 2014 00:45:40 -0500
>> From: Kip Murray<[email protected]>
>> To:"[email protected]" <[email protected]>
>> Subject: [Jprogramming] rpn calculator
>> Message-ID:
>> <CAOfWorgKZnCkZtgFd6L6=_
>> [email protected]>
>> Content-Type: text/plain; charset=UTF-8
>>
>> The following emulates a simple reverse Polish notation calculator which
>> operates on numbers at the bottom of a stack, replacing them by the
>> result.
>> How would you do it? (Beware of line wrap.)
>>
>
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