The named-read-macros Reference Manual

3.1.1 named-read-macros/named-read-macros.asd

Source

named-read-macros.asd.

Parent Component

named-read-macros (system).

ASDF Systems

named-read-macros.

3.1.2 named-read-macros/packages.lisp

Source

named-read-macros.asd.

Parent Component

named-read-macros (system).

Packages

named-read-macros.

3.1.3 named-read-macros/named-read-macros.lisp

Dependency

packages.lisp (file).

Source

named-read-macros.asd.

Parent Component

named-read-macros (system).

Public Interface

• define (macro).
• read-macro-redefinition-warning (condition).
• read-macro-redefinition-warning-name (reader method).
• read-macro-redefinition-warning-prev-type (reader method).

Internals

• check-if-bound (function).
• read-maybe-read-macro (function).
• read-string-end (function).
• readtable-case-transform-fn (function).

3.1.4 named-read-macros/readtables.lisp

Dependency

named-read-macros.lisp (file).

Source

named-read-macros.asd.

Parent Component

named-read-macros (system).

5.1.1 Macros

Macro: define (name &body body) ¶

Creates a named read macro, which executes ‘BODY‘ in a context where ‘*STANDARD-INPUT*‘ is bound to a stream containing just the contents which the read macro was called with, and associates this macro with ‘NAME‘.

Just like a normal macro, ‘BODY‘ should return a Lisp form to then get evaluated where the named read macro was called.

Because ‘NAMED-READ-MACROS‘ hijacks the Lisp reader, we can’t rely on matching parentheses to know when the newly-defined read macro *ends*, so we look for the sequence of characters ‘’END-${NAME}’‘, *immediately* followed by a close parenthesis, in order to know when the read macro ends. Case is checked against ‘NAME‘ by transforming the ending string according to the case of the current readtable; if ‘(SYMBOL-NAME NAME)‘ matches the transformed ending string exactly, we’ve found the end tag. In particular, this means that using ‘DEFINE‘ with a pipe-enclosed symbol with lowercase characters will make such a read macro impossible to end under the standard readtable (though why one would define such a macro is another question entirely!)

Leading whitespace after opening the read macro will not be passed to ‘BODY‘, but trailing whitespace before the ending tag will.

Note that ‘DEFINE‘ has no compile-time effects by default; the rationale is that doing so would also require any functions used by a read macro defined by ‘DEFINE‘ to be available at compile-time. Since this is not the usual, ‘DEFINE‘ explicitly has no compile-time effects to avoid this problem. If you want a named read macro to be available at compile-time, wrap ‘DEFINE‘ and any necessary functions in an explicit ‘EVAL-WHEN‘.

Package

named-read-macros.

Source

named-read-macros.lisp.

5.1.2 Generic functions

Generic Reader: read-macro-redefinition-warning-name (condition) ¶

Package

named-read-macros.

Methods

Reader Method: read-macro-redefinition-warning-name ((condition read-macro-redefinition-warning)) ¶

Source

named-read-macros.lisp.

Target Slot

name.

Generic Reader: read-macro-redefinition-warning-prev-type (condition) ¶

Package

named-read-macros.

Methods

Reader Method: read-macro-redefinition-warning-prev-type ((condition read-macro-redefinition-warning)) ¶

Source

named-read-macros.lisp.

Target Slot

prev-type.

5.1.3 Conditions

Condition: read-macro-redefinition-warning ¶

Package

named-read-macros.

Source

named-read-macros.lisp.

Direct superclasses

style-warning.

Direct methods

• read-macro-redefinition-warning-name.
• read-macro-redefinition-warning-prev-type.

Direct slots

Slot: name ¶

Initargs

:name

Readers

read-macro-redefinition-warning-name.

Writers

This slot is read-only.

Slot: prev-type ¶

Initargs

:prev-type

Readers

read-macro-redefinition-warning-prev-type.

Writers

This slot is read-only.

5.2.1 Ordinary functions

Function: check-if-bound (symb) ¶

Package

named-read-macros.

Source

named-read-macros.lisp.

Function: read-maybe-read-macro (stream &optional char) ¶

Package

named-read-macros.

Source

named-read-macros.lisp.

Function: read-string-end (stream symbol) ¶

Package

named-read-macros.

Source

named-read-macros.lisp.

Function: readtable-case-transform-fn (&optional readtable) ¶

Return a function which will transform any string per the given readtable’s case-sensitivity.

Package

named-read-macros.

Source

named-read-macros.lisp.