Table of Contents
Is Scheme the same as Lisp?
Scheme is a dialect of Lisp that stresses conceptual elegance and simplicity. It is specified in R4RS and IEEE standard P1178. (See the Scheme FAQ for details on standards for Scheme.) Scheme is much smaller than Common Lisp; the specification is about 50 pages, compared to Common Lisp’s 1300 page draft standard.
What are macros in Scheme?
A macro is a symbol that has a transformer procedure associated with it. When Scheme encounters a macro-expression — i.e., a form whose head is a macro —, it applies the macro’s transformer to the subforms in the macro-expression, and evaluates the result of the transformation.
What is a macro in Lisp?
Advertisements. Macros allow you to extend the syntax of standard LISP. Technically, a macro is a function that takes an s-expression as arguments and returns a LISP form, which is then evaluated.
What is the difference between a Scheme procedure and a Scheme macro?
You see the difference? With a procedure every argument is evaluated and bound to the variables, then the body is evaluated. In the macro version the code gets transformed, then evaluated.
How is Scheme opposite to Common Lisp?
Common Lisp has separate scopes for variables and functions; whereas in Scheme there is just one scope — functions are values and defining a function with a certain name is just defining a variable set to the lambda.
In what way are Scheme and Common Lisp opposite of each other?
16. In what way are Scheme and Common LISP opposites of each other? Common LISP allows for static scoping and dynamic scoping Scheme only uses static scoping. Scheme is relatively small while common LISP is large and complex .
What is a macro in racket?
A macro is a syntactic form with an associated transformer that expands the original form into existing forms. To put it another way, a macro is an extension to the Racket compiler. Most of the syntactic forms of racket/base and racket are actually macros that expand into a small set of core constructs.
Why are Lisp macros useful?
Lisp macros work great because of the Lisp syntax nature. Lisp is an extremely regular language (think of everything is a list); macros enables you to treat data and code as the same (no string parsing or other hacks are needed to modify lisp expressions).
What is so special about Lisp macros?
The special power that Lisp macros have is that they can control evaluation (as seen by evaluating the input expression via ~expr and do arbitrary source-to-source transformations with the full power of the language available.
How is scheme opposite to Common Lisp?
Is Racket a Scheme?
The Racket site and documentation will note that Racket is a descendant of Scheme, but most current uses of the word “Scheme” (which implicitly mean PLT Scheme) will be replaced by “Racket.” Racket programmers are Racketeers, of course.
What are the differences between Lisp Scheme and Racket?
Racket is a descendant of Scheme, which in turn is a descendant of Lisp. So while Racket is not Lisp (in the specific Common Lisp sense), it is a Lisp (in the familial sense). Its core ideas—and core virtues—are shared with Lisp. So talking about Racket means talking about Lisp.
What is Lisp full form?
LISP, an acronym for list processing, is a programming language that was designed for easy manipulation of data strings. Developed in 1959 by John McCarthy, it is a commonly used language for artificial intelligence (AI) programming. It is one of the oldest programming languages still in relatively wide use.
What is a Lisp?
A lisp is a speech impediment that specifically relates to making the sounds associated with the letters S and Z. Lisps usually develop during childhood and often go away on their own. But some persist and require treatment. Another name for lisping is sigmatism.