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Questions tagged [r5rs]

The 5th Revised Report on the Algorithmic Language Scheme

The 5th Revised Report on the Algorithmic Language Scheme, R5RS is a de facto standard for Scheme implementations. Schemers take pride in the fact that at 50 pages the specification is shorter than the index for books on some other languages.

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R6RS vs. R5RS scheme

I'm relatively new to scheme and am having a hard time finding a concrete document online overviewing the major changes that happened with R6RS. Anyone care to elaborate?
Chris Bolton
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Differences between Guile Scheme and Standard Scheme (in Racket IDE)?

I've got a bunch of "legacy" Guile Scheme code that I want to get running in the Racket Scheme IDE. There appear to be enough differences to make this a non-trivial exercise. (My level of Scheme knowledge is the level to complete the The Little…
hawkeye
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Scheme, SICP, R5RS, why is delay not a special form?

This is concerning chapter 3.5 from SICP, in which streams are being discussed. The idea is that: (cons-stream 1 (display 'hey)) Should not evaluate the second part of the cons-stream, so it should not print “hey”. This does happen, I get the…
KnowsLittle
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Is there a digest for different "RnRS" Scheme standards?

I need to choose a Scheme standard for an academic compiler implementation. It has to be simple enough, but should still be a powerful language. There are several (RRS–R7RS) standards of Scheme. Is there a public comparison of these reports for…
Necto
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Scheme getting last element in list

Im trying to write a simple scheme function that returns the last element of a list. My function looks like it should work, but I managed to fail on something: (define (last_element l)( (cond (null? (cdr l)) (car l)) (last_element (cdr…
calccrypto
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Extensible macro definitions

Inspired by a comment thread on a related question regarding functions instead of macros. Is there any way to extend a Scheme syntax definition so that it can use the previous definition of the syntax in the new definition? Furthermore, this must be…
Lily Chung
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SICP exercise 1.5 and 1.6

In addition to question What's the explanation for Exercise 1.6 in SICP?. So Dr. Racket (R5RS) evaluates sqrt-iter function with "if" in finite time, clearly showing normal order evaluation. But if I use example from exercise 1.5 (define (p)…
Vasaka
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Multiple lines comments in Scheme (RnRS)

I created this solution: ; use like this: ; (/* content ... */ ) ; or ; (/* content ... */) => #f (define-syntax /* (syntax-rules (*/) ((/* body ... */) #f) ((/* body ... */ r) r))) But is it really the best or easiest…
Felipe
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A "pure" scheme implementation (R5RS) of SHA256?

I can use SHA256 in Scheme using external libraries (Java, C or system dependent) or using a specific Scheme implementation (like Chicken e.g.), but I wonder if there is a "pure" scheme implementation.
Felipe
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Is it possible to "extend" a function / lambda / macro in Scheme?

For example: if I want the function equal? recognize my own type or record, can I add a new behavior of equal?? without erasing or overwriting the old one? Or for example if I want to make the function "+" accept also string?
Felipe
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How do I break a Scheme list into args to be passed to a procedure?

I want to use the predefined (max) function (R5RS) with a list of numbers, which varies in length. Unfortunately, (max) accepts input like this: (max 2 43 5 6) => 43 I'm attempting to use it like so: (define lst '(3 5 53 4 53 54 32)) (max…
ray
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Scheme List Manipulation (Recursion)

The basic problem here is, when given a list, to return all elements of that list other than the last element. For example, given (a b c d) --> return (a b c). I essentially have the function, it's just the Scheme syntax that I'm having trouble with…
Chris Arena
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Differences between the first and second editions of Queinnec's "Lisp in Small Pieces"

I would like to study Queinnec's book "Lisp in Small Pieces". I already have the English version of the first edition, the French version of which appeared in 1994, at the time of the R4RS. A quick look at the table of contents of the second edition…
Alex M.
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Create new identifier with macros

I want a macro that create a new identifier like (new-name first second) => first-second that could be used to define new toplevel bindings (define-syntax define-generic (syntax-rules () ((define-generic (name a b ...)) (begin …
knivil
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Racket and unbound identifier in lambda expression, contrast with r5rs

In DrRacket, when I set the language to R5RS and run the following code: (lambda (x) z) it runs without error and returns #. This makes sense to me; the lambda form defines a procedure whose body has not yet been evaluated, and so that…
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