History: Robin's Palm Writings: ; mooix2

Source of version: 3 (current)

Robin's Palm Writings Category: misc

Navigation: ((Robin's Palm Writings: misc|misc Index)) ((Robin's Palm Writings|Robin's Palm Writings Top-Level Index)) 


; Convert a list of scheme objects into mooix's string representation
; numbers, strings, mooix objects, ?? are OK
(define (scheme->mooix-string slist)
    (display
	; map the elements of slist into a list of newline-terminated mooix strings, which we then output
	(map
	    (lambda (x)
		(cond
		    ((string? x) (string-join x "\n")
		    ((number? x) (string-join (number->string x) "\n")
		    ; If x is a procedure, then either it's a mooix object or an error
		    ((procedure? x)
			(let ((dir (x "dir")))
			    (if (directory? dir)
				(string-join "mooix:" dir "\n")
				(and (display "Procedure which is not a mooix object not a legal return value." (current-error-port)) #f)
			    )
			)
		    )
		)
	    )
	    slist
	)
    )
)

; Convert a mooix string representation to a list of Scheme objects - numbers, strings, mooix-obj, ??
(define (mooix-string->scheme mstring)
    ; Read all STDIN lines, and map each into a Scheme object, returning the resulting list
    (map
	(lambda (x)
	    (let (
		(num (string->number x))
		(mobj (string-prefix? "mooix:" x)))
		(cond
		    ((not (equal? num #f))
			num
		    )
		    (mobj
			(mooix-obj
			    (string-copy x 7)
			)
		    )
		    ; Return all others as strings
		    (else x)
		)
	    )
	)
	(read-string)
    )
; Retrieve or set a file-based field
(define  (file-field this method args)
    (let (
	    (num (length args))
	    (file (this "fieldfile" (list method)))
	)
	; Behaviour is based on number of arguments; zero means return the file, one means set it, more is an error
	(cond
	    ((= num 0)
		(read-string file)
	    )
	    ((= num 1)
		(display (car args) (open-output-file file))
	    )
	    (else (and (display "Non-method field " method " on object mooix:" (make-absolute-pathname (this "dir")) " passed more than one argument.\n" (current-error-port)) #f))
    )
)
; **********
; Regular dispatch table methods follow
; **********
; Returns #t iff the first argument is in the built-in mooix object method list (that is, in dispatch-table), else returns #f
(define (can-dispatch this args)
	(if (equal? #f (assoc (car args) dispatch-table))
		#f
		#t
	)
)
(define (get this args)
	(mooix-obj (car args))
)
(define (hybridgetfield this args)
    (let* (
	(field (car args))
	(file (this "fieldfile" args))
	(dot (string-prefix? "." field))
	; True if not a symlink or dir
	(reg (regular-file?  file))
	(exe (file-execute-access?  file))
	(hybrid (this "test" (list (string-join "." field "-hybrid"))))
	)
	(and
		file
		dot
		reg
		(or (not exe) (and exe hybrid))
		; NB: this relies on file fields and methods never being able to return #f as *data* - if that changes (and it seems a piss-poor idea to change it) this will need to be looked at again
		(this (car args))
	)
    )
)
; Get the field named and return a boolean based on treating its value as  Perl/C true/false (TODO: empty string, no such file, and 0 are false, else true)
(define (test this args)
    (let (
	    (file (this "fieldfile" args))
	)
	(cond
	    ((equal? file "") #f)
	    ((not (file-exists? file)) #f)
	    (else (let* (
		  (string (this (car args)))
		  (num (string->number string))
		)
		(cond
		    ((and num (= 1 num)) #t)
		    ((not (equal? string "")) #t)
		    (else #f)
		)
	    ))
	)
    )
)
History: Robin's Palm Writings: ; mooix2

Source of version: 3 (current)

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