i just forgot to say that in my code <+ is 'define'
On Wed, Oct 11, 2023 at 8:50 AM Damien Mattei <damien.mat...@gmail.com> wrote:
>
> hi,
>
> when i test at toplevel:
> scheme@(guile-user)> (match 1 (1 (define x3) (+ x 1)))
> While compiling expression:
> Syntax error:
> unknown location: definition in expression context, where definitions
> are not allowed, in form (define x3)
>
> but i have this code that works well and have definition in match:
>
> (define (assignment-argument-4 container-eval index1-or-keyword-eval
> index2-or-keyword-eval index3-or-keyword-eval index4-or-step-eval
> expr-eval)
>
> (when (not {(vector? container-eval) or (string? container-eval) or
> (array? container-eval) or (growable-vector? container-eval)})
> (error "assignment : container type not compatible : " container-eval))
>
> {index1-or-keyword-eval-pos <+ index1-or-keyword-eval}
> {index2-or-keyword-eval-pos <+ index2-or-keyword-eval}
> {index3-or-keyword-eval-pos <+ index3-or-keyword-eval}
> {index4-or-step-eval-pos <+ index4-or-step-eval}
>
> (declare container-length container-copy!)
>
> (if (vector? container-eval)
> ($>
> {container-length <- vector-length}
> {container-copy! <- vector-copy!})
> ($> ;; a string
> {container-length <- string-length}
> {container-copy! <- string-copy!}))
>
> ;; transform the negative indexes in positive ones when not slices
> (when {(not (equal? index1-or-keyword-eval-pos slice)) and
> {index1-or-keyword-eval-pos < 0}}
> {index1-or-keyword-eval-pos <- (container-length container-eval) +
> index1-or-keyword-eval-pos})
>
> (when {(not (equal? index2-or-keyword-eval-pos slice)) and
> {index2-or-keyword-eval-pos < 0}}
> {index2-or-keyword-eval-pos <- (container-length container-eval) +
> index2-or-keyword-eval-pos})
>
> (when {(not (equal? index3-or-keyword-eval-pos slice)) and
> {index3-or-keyword-eval-pos < 0}}
> {index3-or-keyword-eval-pos <- (container-length container-eval) +
> index3-or-keyword-eval-pos})
>
>
> (when {(not (equal? index4-or-step-eval-pos slice)) and
> {index4-or-step-eval-pos < 0}}
> {index4-or-step-eval-pos <- (container-length container-eval) +
> index4-or-step-eval-pos})
>
>
> (match (list index1-or-keyword-eval-pos index2-or-keyword-eval-pos
> index3-or-keyword-eval-pos index4-or-step-eval-pos)
>
> ;; T[i1 $ i2 $]
> ((i1 (? (cut equal? <> slice)) i2 (? (cut equal? <> slice)))
> {container-eval[i1 slice i2] <- expr-eval})
>
> ;; T[$ i2 $ s3]
> ;; > {v <+ (vector 1 2 3 4 5 6 7 8 9)}
> ;; '#(1 2 3 4 5 6 7 8 9)
> ;; > {v[$ 6 $ 2] <- (vector -1 -2 -3 -4 -5)}
> ;; > v
> ;; '#(-1 2 -2 4 -3 6 7 8 9)
> (((? (cut equal? <> slice)) i2 (? (cut equal? <> slice)) step-not-used)
>
> (display "we are in match !") (newline)
> {step <+ index4-or-step-eval}
>
> (when {step = 0}
> (error "assignment : slice step cannot be zero"))
>
> {i <+ 0}
>
> (if {step < 0} ;; with negative index we start at end of vector
> (like in Python)
> (for ({k <+ i2} {k >= 0} {k <- k + step})
> {container-eval[k] <- expr-eval[i]}
> {i <- i + 1})
>
> (for ({k <+ 0} {k < i2} {k <- k + step})
> {container-eval[k] <- expr-eval[i]}
> {i <- i + 1}))
>
> container-eval
> )
>
>
> ;; T[i1 $ $ s3]
> ((i1 (? (cut equal? <> slice)) (? (cut equal? <> slice)) step-not-used)
>
> {step <+ index4-or-step-eval}
>
> ;; > {s <+ (string-append "abcdefgh")}
> ;; "abcdefgh"
> ;; {s[3 $ $ 2] <- "0000"}
> ;; > s
> ;; "abc0e0g0"
>
> (when (= 0 step)
> (error "assignment : slice step cannot be zero"))
>
> (let* ((size-input (vector-length container-eval))
> (i 0))
>
> (if (< step 0) ;; with negative index we start at end of
> vector (like in Python)
> (for ((define k (- size-input 1)) (>= k i1) (set! k (+ k step)))
> (vector-set! container-eval
> k
> (vector-ref expr-eval i))
> (set! i (+ 1 i)))
>
> (for ({k <+ i1} {k < size-input} {k <- k + step})
> (vector-set! container-eval
> k
> (vector-ref expr-eval i))
> {i <- 1 + i})))
>
>
> container-eval
> )
>
>
>
> ;; T[i1 i2 i3 i4]
> ((i1 i2 i3 i4)
>
> ;; normal case
> (if (vector? container-eval)
> (function-array-n-dim-set! container-eval expr-eval (reverse
> (list i1 i2 i3 i4))) ;;(array-n-dim-set! array value i1 i2)
> (srfi25-array-set! container-eval index1-or-keyword-eval
> index2-or-keyword-eval index3-or-keyword-eval index4-or-step-eval
> expr-eval))
>
> expr-eval ;; returning a value allow the chaining : {T[3 5 6 2]
> <- A[4 2 3] <- T[2 5]}
> )
>
> ) ;; end match
>
> )
>
> scheme@(guile-user)> {v <+ (vector 1 2 3 4 5 6 7 8 9)}
> $1 = #(1 2 3 4 5 6 7 8 9)
> scheme@(guile-user)> {v[$ 6 $ 2] <- (vector -1 -2 -3 -4 -5)}
> we are in match !
> $2 = #(-1 2 -2 4 -3 6 7 8 9)
>
> seems that match from toplevel is different than in code.
> note: there is no difference in Racket or Kawa , match allow definitions
> inside.
