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Each description of an MIT/GNU Scheme variable, special form, or procedure begins with one or more header lines in this format:
where category specifies the kind of item (“variable”, “special form”, or “procedure”). The form of template is interpreted depending on category.
else
keyword in
the cond
special form, are set in a fixed width font in the
printed manual; in the Info file they are not distinguished.
Parentheses indicate themselves.
A horizontal ellipsis (...) is describes repeated components. Specifically,
thing ...
indicates zero or more occurrences of thing, while
thing thing ...
indicates one or more occurrences of thing.
Brackets, [ ]
, enclose optional components.
Several special forms (e.g. lambda
) have an internal component
consisting of a series of expressions; usually these expressions are
evaluated sequentially under conditions that are specified in the
description of the special form. This sequence of expressions is commonly
referred to as the body of the special form.
When an argument names a Scheme data type, it indicates that the argument must be that type of data object. For example,
indicates that the standard Scheme procedure cdr
takes one argument,
which must be a pair.
Many procedures signal an error when an argument is of the wrong type;
usually this error is a condition of type
condition-type:wrong-type-argument
.
In addition to the standard data-type names (pair, list,
boolean, string, etc.), the following names as arguments
also imply type restrictions:
Some examples:
indicates that the standard Scheme procedure list
takes zero or
more arguments, each of which may be any Scheme object.
indicates that the standard Scheme procedure write-char
must be
called with a character, char, and may also be called with a
character and an output port.