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mirror of https://github.com/kanaka/mal.git synced 2024-11-11 00:52:44 +03:00
mal/elisp/types.el
2016-03-01 23:40:16 +01:00

105 lines
2.9 KiB
EmacsLisp

;;; general accessors
(defun mal-type (mal-object)
(aref mal-object 0))
(defun mal-value (mal-object)
(aref mal-object 1))
(defun mal-meta (mal-object)
(aref mal-object 2))
;;; objects
(defmacro mal-object (name)
(let ((constructor (intern (format "mal-%s" name)))
(predicate (intern (format "mal-%s-p" name))))
`(progn
(defun ,constructor (&optional value meta)
(vector ',name value meta))
(defun ,predicate (arg)
(and (arrayp arg) (eq (aref arg 0) ',name))))))
(mal-object nil)
(mal-object true)
(mal-object false)
(defvar mal-nil (mal-nil))
(defvar mal-true (mal-true 'true))
(defvar mal-false (mal-false 'false))
(mal-object number)
(mal-object string)
(mal-object symbol)
(mal-object keyword)
(mal-object list)
(mal-object vector)
(mal-object map)
(mal-object env)
(mal-object atom)
(mal-object fn)
(mal-object func)
;;; regex
(defvar token-re
(rx (* (any white ?,)) ;; leading whitespace
(group
(or
"~@" ;; special 2-char token
(any "[]{}()'`~^@") ;; special 1-char tokens
(and ?\" (* (or (and ?\\ anything)
(not (any "\\\""))))
?\") ;; string with escapes
(and ?\; (* not-newline)) ;; comment
(* (not (any white "[]{}()'\"`,;"))) ;; catch-all
))))
(defvar whitespace-re
(rx bos (* (any white ?,)) eos))
(defvar comment-re
(rx bos ?\; (* anything)))
(defvar sequence-end-re
(rx bos (any ")]}") eos))
(defvar number-re
(rx bos (? (any "+-")) (+ (char digit)) eos))
(defvar string-re
(rx bos ?\" (* (or (and ?\\ anything)
(not (any "\\\""))))
?\" eos))
;;; errors
(when (not (fboundp 'define-error))
(defun define-error (name message &optional parent)
"Define NAME as a new error signal.
MESSAGE is a string that will be output to the echo area if such an error
is signaled without being caught by a `condition-case'.
PARENT is either a signal or a list of signals from which it inherits.
Defaults to `error'."
(unless parent (setq parent 'error))
(let ((conditions
(if (consp parent)
(apply #'nconc
(mapcar (lambda (parent)
(cons parent
(or (get parent 'error-conditions)
(error "Unknown signal `%s'" parent))))
parent))
(cons parent (get parent 'error-conditions)))))
(put name 'error-conditions
(delete-dups (copy-sequence (cons name conditions))))
(when message (put name 'error-message message)))))
(define-error 'mal "MAL error")
(define-error 'unterminated-sequence "Unterminated token sequence" 'mal)
(define-error 'end-of-token-stream "End of token stream" 'mal)
(define-error 'mal-custom "Custom error" 'mal)