Print Page - Hash-map e contexts

Title: Hash-map e contexts
Post by: cameyo on September 09, 2021, 08:16:14 AM

How to filter only the contexts that represent a hash-map?

Example:

(dolist (_el (symbols))

(if (context? (eval _el))

(println (eval _el) {} (length (eval _el)))))

; -> Class 2

; -> MAIN 0

; -> Tree 0

; -> demo 0

; -> myHash 0

(dolist (_el (symbols))

(if (and (context? (eval _el))

(not (= _el 'MAIN))

(not (= _el 'Tree))

(not (= _el 'Class)))

(println (eval _el) {} (eval-string (string "(" _el ")")))))

; -> demo ()

; -> myHash (("1" 1) ("20" 20) ("57" 57) ("59" 59) ("81" 81))

Is there a way that doesn't use "eval-string" to display / count the values of a context representing a hash-map? "

Title: Re: Hash-map e contexts
Post by: rrq on September 10, 2021, 03:23:41 AM

1) a "hashmap" is a context without default functor, i.e.

Code Select Expand
(and (context? S) (nil? (sym (term S) S nil)))

2) using the symbol as functor results in its list if entries, i.e.

Code Select Expand
(apply S)

Title: Re: Hash-map e contexts
Post by: rrq on September 10, 2021, 03:25:49 AM

tried to edit, to wrap the sym term into an eval, but the server doesn't let me...

Title: Re: Hash-map e contexts
Post by: cameyo on September 10, 2021, 01:57:51 PM

Thank you. I'll do some tests.

Title: Re: Hash-map e contexts
Post by: cameyo on September 18, 2021, 03:14:11 AM

More difficulties:

a context with functor and functions can be a hash-map too.

Title: Re: Hash-map e contexts
Post by: cameyo on January 14, 2022, 06:44:02 AM

This works for me:

Code Select Expand
(define (hash? hash)
  (and (context? (evals hash))
       (not (list? (evals (sym (term hash) hash nil))))))

With "eval" instead of "evals" (to avoid "Internal server error")

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Forum => newLISP in the real world => Topic started by: cameyo on September 09, 2021, 08:16:14 AM