R

radix n.

an integer between 2 and 36, inclusive, which can be used to designate a base with respect to which certain kinds of numeric input or output are performed. (There are n valid digit characters for any given radix n, and those digits are the first n digits in the sequence 0, 1, ..., 9, A, B, ..., Z, which have the weights 0, 1, ..., 9, 10, 11, ..., 35, respectively. Case is not significant in parsing numbers of radix greater than 10, so “9b8a” and “9B8A” denote the same radix 16 number.)

random state n. 

an object of type random-state.

rank n. 

a non-negative integer indicating the number of dimensions of an array.

ratio n. 

an object of type ratio.

ratio marker n. 

a character which is used in the textual notation for a ratio to separate the numerator from the denominator, and which is slash in the standard readtable. See Section 2.1 (Character Syntax).

rational n. 

an object of type rational.

read v.t. 

1. (a binding or slot or component) to obtain the value of the binding or slot. 2. (an object from a stream) to parse an object from its representation on the stream.

readably adv. (of a manner of printing an object O₁)

in such a way as to permit the Lisp Reader to later parse the printed output into an object O₂ that is similar to O₁.

reader

n. 1. a function that reads₁ a variable or slot. 2. the Lisp reader.

reader macro n.

1. a textual notation introduced by dispatch on one or two characters that defines special-purpose syntax for use by the Lisp reader, and that is implemented by a reader macro function. See Section 2.2 (Reader Algorithm). 2. the character or characters that introduce a reader macro₁; that is, a macro character or the conceptual pairing of a dispatching macro character and the character that follows it. (A reader macro is not a kind of macro.)

reader macro function n.

a function designator that denotes a function that implements a reader macro₂. See the functions set-macro-character and set-dispatch-macro-character.

readtable n.

an object of type readtable.

readtable case n.

an attribute of a readtable whose value is a case sensitivity mode, and that selects the manner in which characters in a symbol's name are to be treated by the Lisp reader and the Lisp printer. See Section 23.1.2 (Effect of Readtable Case on the Lisp Reader) and Section 22.1.3.3.2 (Effect of Readtable Case on the Lisp Printer).

readtable designator n.

a designator for a readtable; that is, an object that denotes a readtable and that is one of: nil (denoting the standard readtable), or a readtable (denoting itself).

recognizable subtype n. (of a type)

a subtype of the type which can be reliably detected to be such by the implementation. See the function subtypep.

reference n., v.t. 

1. n. an act or occurrence of referring to an object, a binding, an exit point, a tag, or an environment. 2. v.t. to refer to an object, a binding, an exit point, a tag, or an environment, usually by name.

registered package n.

a package object that is installed in the package registry. (Every registered package has a name that is a string, as well as zero or more string nicknames. All packages that are initially specified by Common Lisp  or created by make-package or defpackage are registered packages. Registered packages can be turned into unregistered packages by delete-package.)

relative

adj. 1. (of a time) representing an offset from an absolute time in the units appropriate to that time. For example, a relative internal time is the difference between two absolute internal times, and is measured in internal time units. 2. (of a pathname) representing a position in a directory hierarchy by motion from a position other than the root, which might therefore vary. “The notation #P"../foo.text" denotes a relative pathname if the host file system is Unix.” See absolute.

repertoire n., ISO

a subtype of character. See Section 13.1.2.2 (Character Repertoires).

report n. (of a condition)

to call the function print-object on the condition in an environment where the value of *print-escape* is false.

report message n.

the text that is output by a condition reporter.

required parameter n.

A parameter for which a corresponding positional argument must be supplied when calling the function.

rest list n. (of a function having a rest parameter)

The list to which the rest parameter is bound on some particular call to the function.

rest parameter n.

A parameter which was introduced by &rest.

restart n. 

an object of type restart.

restart designator n.

a designator for a restart; that is, an object that denotes a restart and that is one of: a non-nil symbol (denoting the most recently established active restart whose name is that symbol), or a restart (denoting itself).

restart function n.

a function that invokes a restart, as if by invoke-restart. The primary purpose of a restart function is to provide an alternate interface. By convention, a restart function usually has the same name as the restart which it invokes. The next figure shows a list of the standardized restart functions.

abort muffle-warning use-value continue store-value

Figure 26.4: Standardized Restart Functions

return v.t. (of values)

1. (from a block) to transfer control and values from the block; that is, to cause the block to yield the values immediately without doing any further evaluation of the forms in its body. 2. (from a form) to yield the values.

return value n. Trad. 

a value₁

right-parenthesis n.

the standard character “)”, that is variously called “right parenthesis” or “close parenthesis” See Figure 2.5.

run time n.

1. load time 2. execution time

run-time compiler n.

refers to the compile function or to implicit compilation, for which the compilation and run-time environments are maintained in the same Lisp image.

run-time definition n.

a definition in the run-time environment.

run-time environment n.

the environment in which a program is executed.