I am frustrated with string-to-number and number-to-string conversion in GIMP scripting. I am runnning GIMP 2.6.8 in Windows Vista. I understand that GIMP's internal Scheme implementation changes over the versions and I can't seem to nail down the documentation. From what I can gather GIMP's Scheme is a subset of TinyScheme and/or s...
There are a bunch of different Scheme interpreters available for the Mac: http://www.dmoz.org/Computers/Programming/Languages/Lisp/Scheme/Implementations/ Which one is generally supported the best? I'm also interested in 64-bit support and multi-core/processor support. ...
What is the standard way to throw and catch exceptions in R6RS Scheme? I'm looking for syntax that works in any version of Scheme (not just PLT) that implements R6RS. R6RS guard syntax looks like it might fit the bill, but can somebody show me an example of how to actually use it? ...
Is it possible to buy the full R6RS in book form? It has, I believe, been published in the Journal of Functional Programming, but I do not subscribe to it. On the other hand, the full R6RS should be a few hundred pages at most. Is there any way to buy a hard copy? ...
I see that SRFI 4 does not mention resizing of vectors. I'm using f64vectors (for which I need fast access), and I'd like to be able to resize them quickly (similar to what realloc does in C), and not necessarily copy the whole vector. Since I didn't find any references to a "resize-f64vector" procedure, I'd like to know why it doesn't ...
Okay so I have started a new language in class. We are learning Scheme and i'm not sure on how to do it. When I say learning a new language, I mean thrown a homework and told to figure it out. A couple of them have got me stumped. My first problem is: Write a Scheme function that returns true (the Boolean constant #t) ifthe parameter i...
Hey everyone, I want to start using Scheme and I have two questions. First, would you recommend using an interpreter or a compiler for Scheme and why? Second, which interpreter or compiler for Scheme would you recommend and why? Thanks! ...
Hi, I have been writing Common Lisp macros, so Scheme's R5Rs macros are a bit unnatural to me. I think I got the idea, except that I don't understand how one would use vector patterns in syntax-rules: (define-syntax mac (syntax-rules () ((mac #(a b c d)) (let () (display a) (newline) (display d) (...
Okay so I am trying to take in a list and sort it from greatest to smallest. Example: > (maxheap (list 5 6 2 1 18 7)) ;output: > (18 7 6 5 2 1) So here's what I got so far: (define (mkmaxheap heaplist) (let ((max (mymax(heaplist)))) ;mymax is a func that returns max number, it works (let (( head (car heaplist)) (tail (cdr he...
I've been working on a project for school that takes functions from a class file and turns them into object/classes. The assignment is all about object oriented programming in scheme. My problem however is that my code doesn't format right. The output it gives me whenever I give it a file to pass in wraps the methods of the class in a...
I'm using R5RS Scheme and I just want to implement a function that returns the intersection of two given lists, but I can't do that because I cannot add an element to a list. Here is my code. How can I fix it? I'm really a beginner in Scheme - this is my first work using Scheme. thx in advance.. (define list3 '()) (define (E7 list1 lis...
Okay this may sound like a ridiculous question, but how do you return a list in scheme.? ...
Okay one of my homework problems is to take a list of lists and return the car of each sublist as a list. I have it to where I can print out the values, but it's not a list. To be honest, I have no clue how to output lists. Here's what I got: (define (car-print alist) (if (null? alist) (newline) (begin (write (car...
Hi guys i need to integrate drscheme into my c# code for my assignment but i could find any luck on the web. Can anyone help me ? I tried ironscheme but got the following error. The type or namespace name 'Dynamic' does not exist in the namespace 'System' (are you missing an assembly reference?) C:\Documents and Settings\Administrato...
So I need to do a game of blackjack simulator, butt can't seem to figure out whats wrong with the shuffle it's suppose to take a card randomly from the pack the put it on top of the pack. The delete it from the rest. so : (ace)(2)(3)(4)(5)...(k) if random card is let say 5 (5)(ace)(2)(3)(4)(5)...(k) then it deletes the 2nd 5 (5)(ace)(2)...
I defined the Scheme procedure to return another procedure with 2 parameters : (define (smooth f) (λ(x dx)(/ (+ (f (- x dx)) (f x) (f (+ x dx))) 3.0))) if i run this procedure with sin procedure with 2 arguments 10 and 0.0001 then it is ok ((smooth sin) 10 0.0001) ==> -0.544021109075966 if i ...
I have a list called hand and another one called deck, the main goal here is to take the first card (or element ) in the list deck and put it in the list hand when i call the fnction draw... > (draw hand deck) (2 C) > (draw hand deck) (2 C) (3 H) > (draw hand deck) (2 C) (3 H) (K D) but everytime i call it the hand never changes valu...
I know that Lisp and Scheme programmers usually say that eval should be avoided unless strictly necessary. I’ve seen the same recommendation for several programming languages, but I’ve not yet seen a list of clear arguments against the use of eval. Where can I find an account of the potential problems of using eval? For example, I know ...
In Chapter 16 of "The Seasoned Schemer", the authors define a recursive procedure "depth", which returns 'pizza nested in n lists, e.g (depth 3) is (((pizza))). They then improve it as "depthM", which caches its return values using set! in the lists Ns and Rs, which together form a lookup-table, so you don't have to recurse all the way d...
Hi, I'm stuck on the extended exercise 28.2 of How to Design Programs. Here is the link to the question: http://www.htdp.org/2003-09-26/Book/curriculum-Z-H-35.html#node_chap_28 I used a vector of true or false values to represent the board instead of using a list. This is what I've got which doesn't work: #lang Scheme (define-struc...