2.0 syntax
This commit is contained in:
parent
d02322ce73
commit
d5b91b7fd2
GPG Key ID:
5BEBEEAB2C73D520
65
README.md
65
README.md
|
|
@ -9,8 +9,7 @@ code).
|
|||
|
||||
## Usage
|
||||
|
||||
**TL;DR:** `[object slot-name]` is like `object.slotName` in C++, and
|
||||
`[object (.method args)]` is like `object.method(args)` in C++.
|
||||
**TL;DR:** `[object (method args)]` is like `object.method(args)` in C++.
|
||||
|
||||
First, to enable `objective-lisp`'s syntax, just load the system:
|
||||
``` common-lisp
|
||||
|
|
@ -18,66 +17,44 @@ First, to enable `objective-lisp`'s syntax, just load the system:
|
|||
```
|
||||
|
||||
`objective-lisp`'s syntax takes the form of a special S-expression, contained
|
||||
in square brackets rather than parentheses. Each form within treats the previous
|
||||
form as its subject, like a chain of `.` (dot) operators in C-like languages.
|
||||
in square brackets rather than parentheses. Each expression within acts upon the
|
||||
result of the previous one, like a chain of `.` (dot) operators in C-like
|
||||
languages.
|
||||
```common-lisp
|
||||
[foo bar baz quux]
|
||||
;; C++: foo.bar.baz.quux
|
||||
[foo (bar) (baz) (quux)]
|
||||
;; C++: foo.bar().baz().quux()
|
||||
```
|
||||
|
||||
To access a slot, just put the slot name after the object:
|
||||
To call a method, just write it after the object:
|
||||
``` common-lisp
|
||||
[object slot-name]
|
||||
;; => (slot-value object 'slot-name)
|
||||
|
||||
(setf [object slot-name] value)
|
||||
;; => (setf (slot-value object 'slot-name) value)
|
||||
[object (method args...)]
|
||||
;; => (method object args...)
|
||||
```
|
||||
|
||||
`slot-name` doesn't have to be an unquoted symbol:
|
||||
Slot accessors, and other methods that don't take additional arguments, can be
|
||||
written without enclosing parentheses:
|
||||
``` common-lisp
|
||||
(defun choose-slot (x)
|
||||
(if (<= x 0) 'pos-slot 'neg-slot))
|
||||
(setf [object (choose-slot -1)] value)
|
||||
|
||||
(defvar slot-var 'slot-name)
|
||||
(setf [object `,slot-var] value)
|
||||
```
|
||||
|
||||
To call a method, write an S-expression as you normally would, but put a `.`
|
||||
(dot) before its name:
|
||||
``` common-lisp
|
||||
[object (.method arg-1 arg-2 ... arg-N)]
|
||||
;; => (method object arg-1 arg-2 ... arg-N)
|
||||
[object get-something]
|
||||
;; => (get-something object)
|
||||
```
|
||||
|
||||
Under the hood, this just passes `object` as the first argument to `method`, so
|
||||
you can do stuff like this (I won't kinkshame you, but your coworkers might):
|
||||
```common-lisp
|
||||
[object slot-name (.setf value)]
|
||||
;; => [(slot-value object 'slot-name) (.setf value)]
|
||||
[object (slot-value 'slot-name) (setf value)]
|
||||
;; => [(slot-value object 'slot-name) (setf value)]
|
||||
;; => (setf (slot-value object 'slot-name) value)
|
||||
```
|
||||
|
||||
And, of course, you can chain multiple slot accesses and method calls together:
|
||||
To access slots directly, use the `:slot` keyword:
|
||||
``` common-lisp
|
||||
[object child (.method-of-child) (.method-of-return-value) slot-of-return-value]
|
||||
;; => [(slot-value object 'child) (.method-of-child) ...]
|
||||
;; => [(method-of-child (slot-value object 'child)) (.method-of-return-value) ...]
|
||||
;; => [(method-of-return-value (method-of-child ...)) slot-of-return-value]
|
||||
;; => (slot-value (method-of-return-value ...) 'slot-of-return-value)
|
||||
```
|
||||
|
||||
**NEW:** You can also call slot accessors without wrapping them in a cons. (This
|
||||
works for any method that takes no additional arguments, but that might cause
|
||||
code readability issues.)
|
||||
``` common-lisp
|
||||
[object .slot-accessor]
|
||||
;; => (slot-accessor object)
|
||||
[object :slot slot-name]
|
||||
;; => (slot-value object 'slot-name)
|
||||
```
|
||||
|
||||
## License
|
||||
`objective-lisp` is public domain. You can do whatever you want with it. I don't
|
||||
really care about credit, it's just a silly little thing I wrote in a few hours.
|
||||
`objective-lisp` is public domain (CC0). You can do whatever you want with it. I
|
||||
don't really care about credit, it's just a silly little thing I wrote in a few
|
||||
hours. (And then rewrote just now because the syntax sucked.)
|
||||
|
||||
But if you find it useful, *please* let me know. I'd love to hear about it.
|
||||
|
|
|
|||
|
|
@ -3,8 +3,8 @@
|
|||
|
||||
(defsystem "objective-lisp"
|
||||
:description "Syntactic sugar for object-oriented Lisp."
|
||||
:version "1.0"
|
||||
:version "2.0"
|
||||
:author "~keith"
|
||||
:homepage "https://bytes.keithhacks.cyou/keith/objective-lisp"
|
||||
:license "Public Domain"
|
||||
:license "Public Domain/CC0"
|
||||
:components ((:file "objective-lisp")))
|
||||
|
|
|
|||
|
|
@ -3,94 +3,49 @@
|
|||
|
||||
(defpackage objective-lisp
|
||||
(:use common-lisp)
|
||||
(:export +open-construct-char+ +close-construct-char+ +method-char+
|
||||
read-construct-contents
|
||||
destructure-construct
|
||||
read-method-name
|
||||
read-open-construct
|
||||
(:export +open-char+ +close-char+
|
||||
read-construct-item
|
||||
read-construct
|
||||
read-unexpected))
|
||||
|
||||
(in-package objective-lisp)
|
||||
|
||||
(defparameter +open-construct-char+ #\[)
|
||||
(defparameter +close-construct-char+ #\])
|
||||
(defparameter +method-char+ #\.)
|
||||
(defconstant +open-char+ #\[)
|
||||
(defconstant +close-char+ #\])
|
||||
|
||||
;; DONE
|
||||
;; (setf (slot-value object 'slot) value)
|
||||
;; => (setf [object slot] value)
|
||||
(defun read-construct-item (sexpr stream)
|
||||
"Recursively read and rewrite an objective-lisp construct."
|
||||
(if (char= (peek-char t stream t nil t) +close-char+)
|
||||
; We've hit the end, return the sexpr we built
|
||||
(progn (read-char stream t nil t)
|
||||
sexpr)
|
||||
(let ((item (read stream t nil t)))
|
||||
(cond
|
||||
; Method call [object (method args...)]
|
||||
((consp item)
|
||||
(read-construct-item `(,(car item) ,sexpr ,@(cdr item))
|
||||
stream))
|
||||
; Slot access [object :slot slot-name]
|
||||
((eq item :slot)
|
||||
(read-construct-item `(slot-value ,sexpr ',(read stream t nil t))
|
||||
stream))
|
||||
; Consless method call [object method]
|
||||
((symbolp item)
|
||||
(read-construct-item `(,item ,sexpr)
|
||||
stream))
|
||||
; Something else
|
||||
(t (error "Unexpected item ~S" item))
|
||||
))))
|
||||
|
||||
;; DONE
|
||||
;; (setf (slot-value (slot-value object 'slot-a) 'slot-b) value)
|
||||
;; => (setf [object slot-a slot-b] value)
|
||||
|
||||
;; TODO
|
||||
;; (object-method object args...)
|
||||
;; => [object (.method args...)]
|
||||
|
||||
(defun read-construct-contents (stream end-char)
|
||||
"Read the contents of an objective-lisp construct."
|
||||
(loop until (char= (peek-char t stream t nil t) end-char)
|
||||
collect (read stream t nil t)
|
||||
; Skip over end-char
|
||||
finally (read-char stream t nil t)))
|
||||
|
||||
(defun quote-if-symbol (x)
|
||||
"Quote x if it's a symbol, return it verbatim otherwise."
|
||||
(if (symbolp x) `(quote ,x) x))
|
||||
|
||||
(defun method-call-p (x)
|
||||
"Check if x is a sexpr of the form (.method args...)"
|
||||
(and (consp x) (consp (car x)) (eq (caar x) :method-call)))
|
||||
|
||||
(defun consless-method-call-p (x)
|
||||
"Check if x is of the form .method (no arguments)"
|
||||
(and (consp x) (eq (car x) :method-call)))
|
||||
|
||||
(defun destructure-construct (construct)
|
||||
"Recursively destructure an objective-lisp construct."
|
||||
(cond
|
||||
; Nothing left to destructure, return car
|
||||
((not (cdr construct))
|
||||
(car construct))
|
||||
; Method call [object (.method args...)]
|
||||
; => [object ((:method-call . method) args...)]
|
||||
((method-call-p (cadr construct))
|
||||
(let ((method-call (cadr construct)))
|
||||
(destructure-construct
|
||||
(cons `(,(cdar method-call) ,(car construct) ,@(cdr method-call))
|
||||
(cddr construct)))
|
||||
))
|
||||
; Consless method call [object .method]
|
||||
; => [object (:method-call . method)]
|
||||
((consless-method-call-p (cadr construct))
|
||||
(destructure-construct
|
||||
(cons `(,(cdadr construct) ,(car construct))
|
||||
(cddr construct)))
|
||||
)
|
||||
; Slot access [object slot]
|
||||
(t
|
||||
(destructure-construct
|
||||
(cons `(slot-value ,(car construct) ,(quote-if-symbol (cadr construct)))
|
||||
(cddr construct)))
|
||||
)))
|
||||
|
||||
(defun read-method-name (stream char)
|
||||
"Read an objective-lisp method name."
|
||||
(declare (ignore char))
|
||||
(cons :method-call (read stream t nil t)))
|
||||
|
||||
(defun read-open-construct (stream char)
|
||||
(defun read-construct (stream char)
|
||||
"Read an objective-lisp construct."
|
||||
(declare (ignore char))
|
||||
(let ((*readtable* (copy-readtable)))
|
||||
(set-macro-character +method-char+ 'read-method-name
|
||||
t) ; non-terminating so (12.34) doesn't become (12 (:method-call . 34))
|
||||
(destructure-construct (read-construct-contents stream +close-construct-char+))))
|
||||
(read-construct-item (read stream t nil t) ; 1st sexpr is the object, don't rewrite it
|
||||
stream))
|
||||
|
||||
(defun read-unexpected (stream char)
|
||||
(declare (ignore stream))
|
||||
(error "Unexpected character ~S" char))
|
||||
|
||||
(set-macro-character +open-construct-char+ 'read-open-construct)
|
||||
(set-macro-character +close-construct-char+ 'read-unexpected)
|
||||
(set-macro-character +open-char+ 'read-construct)
|
||||
(set-macro-character +close-char+ 'read-unexpected)
|
||||
|
|
|
|||
Loading…
Reference in New Issue