Scheme is a functional programming language that is a dialect of Lisp. It has a minimalist design with a standard specification and many implementations.
1
vote
1answer
55 views
Scheme : Lambda inside quoted list is unbound
I'm programming a small lisp/scheme interpreter and I came across the following situation :
When a quoted list contains lambdas, they are not parsed as lambdas.
Here is a sample code (live on ...
6
votes
2answers
203 views
What is the minimum practical definition for the Scheme language?
What is the smallest practical set of primitives that can be used to define the Scheme language?
For example, map can be defined as
(define (map proc lis)
(cond ((null? lis)
'())
...
0
votes
1answer
109 views
Two dimensional matrix-like data type using lists and/or mutable lists
I am trying to think of an implementation of a two dimensional matrix-like data type.
Normally I would take an array of arrays but I'm bound to a relatively low language level which only provides ...
20
votes
4answers
2k views
What about LISP, if anything, makes it easier to implement macro systems?
I'm learning Scheme from the SICP and I'm getting the impression that a big part of what makes Scheme and, even more so, LISP special is the macro system. But, since macros are expanded at ...
1
vote
1answer
60 views
Looking for advice for the following MS SQL Schema
We currently have the following SQL Schema:
Projects
Budgets
BudgetTabs
BudgetSections
BudgetTasks
BudgetTaskDetails
...
2
votes
0answers
199 views
Abstract List Functions in Racket/Scheme
I'm completely stuck on a problem to write a function that does NOT use recursion, locals, or lambda. Only abstract list functions can be used.
The function must input a list of positive integers, ...
4
votes
3answers
2k views
Lambda expressions with no parameters in Haskell and / or lambda calculus
In eager languages like Scheme and Python, you can use a lambda expression without parameters to delay evaluation, e.g. in Scheme (Chicken Scheme):
#;1> (define (make-thunk x) (lambda () (+ x 1)))
...
40
votes
2answers
4k views
Why do some languages round to the nearest EVEN integer?
Programming languages like Scheme (R5RS) and Python (see this Question) round towards the nearest even integer when value is exactly between the surrounding integers.
What is the reasoning behind ...
1
vote
1answer
117 views
Why is (f . l) not allowed and equal to (apply f l)?
In scheme when defined
(define f (lambda (a b c d) d))
(define l (list 'a 'b 'c 'd))
Why it does not do argument destructuring? I mean arguments should evaluate first, why destructuring is not ...
11
votes
2answers
2k views
Approaching SICP in Clojure instead of Scheme
I am a third year bachelor student in a software engineering program, and I brought up the idea of reading SICP to an adviser to gain a deeper and more fundamental understanding of the principles ...
0
votes
1answer
317 views
Continuations, coroutines, and tail-call optimization
I am trying to learn continuations and use them to implement coroutines in Scheme.
I have two procedures (coroutines) a and b, and I switch between them in the following way:
;; c is a continuation.
...
4
votes
1answer
176 views
Tail-recursive implementation of take-while
I am trying to write a tail-recursive implementation of the function take-while in Scheme (but this exercise can be done in another language as well). My first attempt was
(define (take-while p xs)
...
3
votes
3answers
645 views
If Scheme is untyped, how can it have numbers and lists?
Scheme is said to be just an extension of the Untyped Lambda Calculus (correct me if I am wrong). If that is the case, how can it have Lists and Numbers? Those, to me, look like 2 base types. So I'd ...
-1
votes
1answer
288 views
Designing XML - confused between attributes and elements [closed]
I have to design an xml structure to set standard data exchange with my client.
We deal with payments and its related data.
At now, my XML data looks like this:
<PAYMENTS>
...
5
votes
1answer
389 views
What features does MIT-Scheme have that make it ideal for SICP?
I've been thinking about trying to get through the SICP again, this time well-armed with a better idea of what the SICP is meant to accomplish, and being older and wiser than my first attempt back in ...
6
votes
1answer
1k views
What's the difference between lists constructed by quote and those constructed by cons in Scheme?
(define ls1 '((1 . 2) 1 . 2))
(set-car! (car ls1) 6)
ls1
(define ls2 (cons '(1 . 2) '(1 . 2)))
(set-car! (car ls2) 6)
ls2
After set-car!ing, ls1 will be ((6 . 2) 1 . 2) and ls2 ((6 . 2) 6 . 2). It ...
5
votes
1answer
316 views
Why does DrRacket IDE considers some identifiers as “symbols” and some as “keywords”? What is the difference?
Why does DrRacket (kind of Scheme) IDE highlights some of the identifiers as "keywords" (for example define, lambda, send*), and the others as "symbols" (user defined identifiers, +, -, abs, send, ...
2
votes
3answers
326 views
Why it is `(cons 1 (cons 2 (cons 3 nil)))` and not `(cons 3 (cons 2 (cons 1 nil)))` for [1,2,3]?
Is there any special reason that to construct list in Scheme you use
(cons 1 (cons 2 (cons 3 nil)))
instead of
(cons 3 (cons 2 (cons 1 nil)))
? While the first seems more obvious because it ...
4
votes
2answers
478 views
Is there any particular reason for the use of lists over queues in functional programming languages?
Most functional programming languages such as Scheme and Haskell use lists as their main data structure. Queues are identical to lists, except for the fact appending to the end - not to the begin - ...
4
votes
3answers
415 views
Obscurity of Lisp in collaborative projects [closed]
I'm playing with the idea of learning Scheme but I have a few misgivings.
From what I understand Lisp makes heavy use of macros that allow programmers to drastically change the language itself. I ...
0
votes
1answer
324 views
Is R6RS backwards compatible with R5RS?
Is the new Scheme standard, R6RS which was published in 2007, backwards compatible with the older standard R5RS? If not, is there a compatibility mode in R6RS?
1
vote
2answers
583 views
Multiple Data Types for Single Variable in C
I am trying to implement basic cons, car and cdr of SCHEME in C. I have made a simple program that allows me to cons two integers as shown in the main program. However, I want my program to be able to ...
6
votes
4answers
1k views
What makes Common Lisp “big”? [closed]
I've been learning both Common Lisp and Racket, and one thing that I consistently hear is that Racket is a much "smaller" language than Common Lisp. I was wondering what this really meant. As far as I ...
0
votes
1answer
164 views
Show all definitions in Scheme?
I want to see all user-made definitions in a Scheme REPL, both loaded from files and entered at the REPL. Is there any way to "dump all definitions"?
E.g. if there is:
(define (plusone x) (+ 1 ...
3
votes
1answer
181 views
“Final” Scheme REPL definitions: how to save them?
Is there a way to show and save all "final" definitions entered into a Scheme REPL into a text file?
Say, if I have defined in the REPL:
(define (increase x) (+ 1 x))
(define (multbytwo x) ...
0
votes
1answer
324 views
In what way is JavaScript (ECMAScript) similar to Self and Scheme
When looking at the ECMAScript 4th Edition specification here it mentions that
ES3 is a simple, highly dynamic, object-based language that takes its major ideas from the languages Self and ...
3
votes
4answers
316 views
In Scheme, what is formally a program's state?
I think i've understood more or less what a parsed Scheme program looks like (a binary tree with atomic values on the leaves, if i have understood correctly). Can anybody please define to me, or give ...
5
votes
1answer
551 views
Types in Lisp and Scheme
I see now that Racket has types. At first glance it seems to be almost identical to Haskell typing. But is Lisp's CLOS covering some of the space Haskell types cover? Creating a very strict Haskell ...
8
votes
2answers
387 views
Who first coined the term Higher Order Function and/or First Class Citizen?
I've come to understand that long before Haskell, O'Caml or LISP, higher order functions were an academic research subject and in mathematics, Schönfinkel (in 1967) and Haskell Curry (in 1968) already ...
28
votes
2answers
2k views
Applying Denotational Semantics to design of Programs
I've read a bit on denotational semantics (DS) and I'm very intrigued about the process of designing computer programs where types and functions have strong and clear mappings to mathematics.
Are ...
8
votes
1answer
544 views
SICP - Why use accumulate with cons when filter already passes back a list
In SICP 2nd Edition section 2.2.3,
the authors have the following code:
(define (even-fibs n)
(accumulate cons
nil
(filter even?
(map fib
...
0
votes
1answer
137 views
What is the meaning of # in R5RS Scheme number literals
There is a partial answer on Stack Overflow, but I'm asking something a teeny bit more specific than the answers there.
So... Does the formal semantics (Section 7.2) specify the meaning of such a ...
4
votes
3answers
336 views
Is Reading the Spec Enough? [closed]
This question is centered around Scheme but really could be applied to any LISP or programming language in general.
Background
So I recently picked up Scheme again having toyed with it once or twice ...
8
votes
9answers
3k views
OS choice for functional developing [closed]
I'm mainly a .NET developer so I normaly use Windows/VisualStudio (that means: I'm spoiled) but I'm enjoying Haskell and other (mostly functional) languagues in my spare time.
Now for Haskell the ...
4
votes
3answers
470 views
Can't understand example using continuations
I'm reading the r6rs Scheme report and am confused by the explanation of continuations (I find it to be too dense and lacking of examples for a beginner).
What is this code doing and how does it ...
1
vote
2answers
494 views
Why does Scheme r5rs have no module system [closed]
With all the controversy surrounding scheme r6rs, I stuck with r5rs and I am wondering why the designers decided to not implement a module system. How does one organize code in this?
6
votes
3answers
748 views
Am I getting Scheme wrong?
Inspired by the numerous posts about the importance of learning Lisp/Scheme I started to learn Scheme two days back, I am using the book "The little Schemer" and have completed half of it.
But I ...
6
votes
2answers
1k views
What is a dotted pair's analogy in other Lisp implementations?
What is Scheme's dotted pair construct analogous to in other Lisp implementations? I can make a vector or list quite easily, and understand those in Clojure, even though the syntax is a little ...
9
votes
3answers
2k views
Why do .NET modules separate module file names from namespaces?
In implementations of the Scheme programming language (R6RS standard) I can import a module as follows:
(import (abc def xyz))
The system will try to look for a file $DIR/abc/def/xyz.sls where $DIR ...
22
votes
6answers
4k views
how a pure functional programming language manage without assignment statements?
When reading the famous SICP, I found the authors seem rather reluctant to introduce the assignment statement to Scheme in Chapter 3. I read the text and kind of understand why they feel so.
As ...
15
votes
5answers
2k views
How useful are Lisp macros?
Common Lisp allows you to write macros that do whatever source transformation you want.
Scheme gives you a hygienic pattern-matching system that lets you perform transformations as well. How useful ...
7
votes
1answer
333 views
Process arbitrarily large lists without explicit recursion or abstract list functions?
This is one of the bonus questions in my assignment.
The specific questions is to see the input list as a set and output all subsets of it in a list. We can only use cons, first, rest, empty?, empty, ...
23
votes
3answers
9k views
On the path to Enlightenment: Scheme, Common Lisp, Clojure? [closed]
A lot of people smarter than me keep writing about when you learn Lisp it makes you a better programmer because you "get it".
Maybe all I hear about Lisp(s) changing your life is just a big practical ...
71
votes
11answers
9k views
Why is Scheme my first language in university?
I hear about C, C++, Java every day whenever people starting talking about computer science, but in my first computer science class we are asked to write in Scheme (DrRacket).
Why is that?
What ...
13
votes
2answers
2k views
Is IronScheme complete enough or stable enough to be worth learning?
IronScheme is mentioned on Wikipedia as a successor to a failed project called IronLisp, bringing Lisp to CLR and .NET, the way Clojure does for the JVM. Does anyone have experience with this ...
8
votes
5answers
1k views
Wrapping my mind around prefix notation?
I'm reading about LISP.
I understand how prefix notation works at a certain level, but I was wondering if there are any tricks to making it intuitive.
4
votes
2answers
2k views
Scheme Stream Implementation
After working my way through SICP I decided to work though some Project Euler problems using scheme. In this particular problem I am trying to generate an infinite stream of integers however I am ...
33
votes
11answers
14k views
Scheme vs Haskell for an Introduction to Functional Programming?
I am comfortable with programming in C and C#, and will explore C++ in the future. I may be interested in exploring functional programming as a different programming paradigm. I am doing this for fun, ...
7
votes
6answers
1k views
Reading SICP with F#? [closed]
I've been meaning to read the SICP book for a while, and am finally about to get around to it (now that I can read it on Kindle :) I'd like to learn a functional language, and I use C# at work so ...
114
votes
5answers
30k views
Scheme vs Common Lisp: Which characteristics made a difference in your project? [closed]
There are no shortage of vague "Scheme vs Common Lisp" questions on both StackOverflow and on this site, so I want to make this one more focused. The question is for people who have coded in both ...
