Menu

Show posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Show posts Menu

Messages - lyl

Pages 1 2 3
#31
newLISP in the real world / Re: slice with negative "int-length"
April 25, 2019, 01:00:36 AM
@rickyboy Really really appreciate your works on my post and your valueable suggestions!!
#32
newLISP in the real world / Re: slice with negative "int-length"
April 24, 2019, 07:06:54 AM
Thank you so much for your help @rickboy!! I learned a lot from you.

Based on your idea, I construct "myslice" as below:


Code Select
(define (myslice xs
        idx
        (len (if (< idx 0)
   (- idx)
   (- (length xs) idx))))
 
  (if (or (>= idx (length xs)) (< idx (- (length xs))))
      (if (list? xs) '()
 (string? xs) "")

      (begin
(setq idx (if (>= idx 0) idx (+ idx (length xs))))
(if (< len 0)
   (slice xs
    (let (new-idx (+ 1 idx len)) (if (>= new-idx 0) new-idx 0))
    (let (abs-len (abs len)) (if (<= abs-len (+ 1 idx)) abs-len (+ 1 idx)))
  )
   (slice xs idx len)
   )
)
      )
  )

Code Select
;; test
(setq a '(0 1 2 3 4 5))
(setq b "Hello World")
(myslice a 2) ;;->(2 3 4 5)
(myslice a 3 2) ;;->(3 4)
(myslice a 3 4) ;;->(3 4 5)
(myslice a 3 -4) ;;->(0 1 2 3)
(myslice a 3 -5) ;;->(0 1 2 3)
(myslice a 6 -2) ;;->()
(myslice a -7 2) ;;->()
(myslice a 8 -2) ;;->()
(myslice a -3 2) ;;(3 4)
(myslice a -3 -3) ;;(1 2 3)
(myslice a -3 -8) ;;(0 1 2 3)
(myslice b 4 3) ;;->"o W"
(myslice b 4 12) ;;->"o World"
(myslice b -4 -6) ;;-> "llo Wo"
(myslice b -4 -18) ;;-> "Hello Wo"
(myslice b 20 6) ;;-> ""
#33
newLISP in the real world / slice with negative "int-length"
April 23, 2019, 01:46:05 AM
I don't quite understand how the function slice works with negative "int-length".

The following example comes from the manual:
Code Select
(slice '(a b c d e f) 2 -2)  → (c d)
As explained in manual:
QuoteIf int-length is negative, slice will take the parameter as offset counting from the end and copy up to that offset

As my view, -2 seems to point to "e"(-1 points to "f"), so why is not the result  (c d e)?



And how to design a function like this:
Code Select
(myslice '(0 1 2 3 4 5) 2 -2) ->(1 2)
(myslice '(0 1 2 3 4 5) 4 -3) ->(2 3 4)
(myslice '(0 1 2 3 4 5) 4 -1) ->(4)
(myslice "newLISP" 4 -2) ->"LI"
That means the negative symbol will cause myslice select elements in opposite direction.
#34
newLISP in the real world / Get a frame of lines from a table by filter
April 20, 2019, 05:41:53 PM
I have a table like this:
Code Select
(setq lst '(("header1" "header2" "header3") ( "11" "12" "13") ("21" "22" "23") ("31" "32" "33") ("41" "42" "43" )))

I want to get some continueous lines e.g. from the first line to the third line by this:
Code Select
(filter (and (>= $idx 1) (<= $idx 3)) lst)  ;; '(( "11" "12" "13") ("21" "22" "23") ("31" "32" "33") ) wanted.

But I find the function "filter" does not support "$idx".

So, is there a better way to achieve this?
#35
newLISP in the real world / Re: anti-select elements of a list
December 22, 2018, 04:43:29 AM
Many thanks all of you for these beautiful solutions!!
#36
newLISP in the real world / Re: anti-select elements of a list
December 21, 2018, 05:18:53 PM
@fdb '(1 2) in my example means the position of elements in lst, not elements themselves. I think I give a poor example.
#37
newLISP in the real world / Re: anti-select elements of a list
December 21, 2018, 06:45:05 AM
Quote from: "newBert"Here is a solution (probably not the only one, nor the best) :
Code Select
newLISP v.10.7.5 64-bit on Linux IPv4/6 UTF-8 libffi, options: newlisp -h

> (select '(0 1 2 3 4) (difference (index true? '(0 1 2 3 4)) '(1 2)))
(0 3 4)
> ;; maybe clearer:
>
(let (lst '(0 1 2 3 4))
  (select lst (difference (index true? lst) '(1 2))))

(0 3 4)
>


If the lst contains nil(0 1 2 3 nil), how to do?
#38
newLISP in the real world / non-ascii characters in path?
December 20, 2018, 07:08:22 PM
I have the following files in a directory:

- newlisp.exe   (newlisp v10.7.4(Win64-UTF8))

- main.lsp

- 01-寻找当前目录下是否有所需文件.lsp



In the main.lsp, the first line of code is:
Code Select
(load "01-寻找当前目录下是否有所需文件.lsp")

When I run "
Code Select
newlisp main.lsp" in this directory of console, error message given:
QuoteERR: problem accessing file in function load : "01-寻找当前目录下是否有所需文件.lsp"


My OS is win7(64), and I guess non-ascii characters in path cause this problem. But why is the newlisp v10.7.4(Win64-UTF8) not able to recognize these non-ascii charactors? And how to solve this problem?
#39
newLISP in the real world / anti-select elements of a list
December 20, 2018, 06:18:41 PM
The function "select" can be used to select multi-elements of a list at one time, for example:
Code Select
(select '(0 1 2 3 4) '(1 2)) ->(1 2)



Yet what I want is to get all elements other than those "selceted", that is to say, I want to obtain (0 3 4) from above example.

I tried with the function "filter" like this:
Code Select
(filter (not (find $idx '(1 2))) '(0 1 2 3 4))
but it fails because "filter" does not support $idx.



So, is there a better way to anti-select elements in a list at one time by another list which assign positions those elements to be deleted?
#40
newLISP in the real world / Re: abbreviation of arguments in function
December 10, 2018, 05:11:16 AM
Quote from: "cameyo"
Code Select
(define (f converse-rate-list)
  (local (rate) (setq rate converse-rate-list))
)
I am almost sure that this is not what you are searching for...  :-)

cameyo


I'd like to have a try this. Thank you.
#41
newLISP in the real world / Re: abbreviation of arguments in function
December 10, 2018, 05:08:56 AM
@rickyboy What? Newlisp has a elisp style? It's a supprise!
#42
newLISP in the real world / abbreviation of arguments in function
December 09, 2018, 12:44:27 AM
To understand the meaning of function arguments, I give there arguments long names. However, it's so boring to use these long names in function body.

I ttied like this:


Code Select
(define (f converse-rate-list (define rate converse-rate) )
   body in which "rate" instead of converse-rate-list is use....)

But it fails.

Is there a better way to achievable this goal? That is to say, how to bind a symbol to a argument of function?
#43
newLISP in the real world / Re: string evaculat in (if ...)
December 06, 2018, 05:22:23 PM
@TedWalther

I'm very sorry. Now it does work and get the result I want.

I don't know why? Maybe I make some mistake?

newLISP-10.7.1 I use in Win7.

And many thanks for your prompt response!!
#44
newLISP in the real world / string evaculat in (if ...)
December 06, 2018, 05:04:10 PM
Here is my code:


Code Select
(setq file-name-extension ".csv")
(if file-name-extension file-name-extension "")

I think the "if" expression should return a string ".csv", but I get nil.

Why is file-name-extension in the true part of the "if" expression not evaculated?
Pages 1 2 3