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"Hidden" parameters in Pcell

RVERP

Hello,

 When I generate a Pcell using a function and it's arguments, my pcells do not generate correctly.

 I understand why, once the pcell is compiled, he has unknown variables, the one that where passed by the function.  IfI replace this variables with a parameter of the pcell, the functions arguments are stored and the pcell compiles.

I don't want to use variables for this to prevent having a long list.

Is there another way of doing this, some sort of hidden parameter or property?

 

So this doesn't work:

procedure( makeAcell(arg1 arg2)

pcDefinePcell(
 ...
 ...
w = arg1*arg2

))

 

This does work, but it's not what I want:

procedure( makeAcell(arg1 arg2)
 ...
;PCELL PARAMETERS
((Arg1 int arg1) (Arg2 int arg2))
 ...
))

 

Parents

  • The problem is that the variables arg1 and arg2 are out of scope when the body of the pcell is evaluated. You might think that you could solve this with SKILL++ (which has lexical scoping), but pcDefinePCell is not supported in SKILL++ (it can call SKILL++ functions, but can't be used in SKILL++ - mainly because the pcell wouldn't be able to store information about the lexical environment in which it was called). One way is to store the arguments on the cellView somewhere (as properties say), but another might just be to do:

    procedure(makeACell(arg1 arg2)
    eval(`pcDefinePCell(
      ...
      ...
      w=,arg1*,arg2
    ) ;pcDefinePCell
    ) ; eval
    ) ; procedure

    The quote before the pcDefinePCell is a backquote. This means that the code is not evaluated - but a list of the code - but rather than a normal quote, backquote allows selective evaluation. You precede the variable with a comma to selectively evaluate it.

    To illustrate what I mean:

    val1=20
    val2=30
    lst=`(a b ,val1 c ,val2)

    then lst will contain (a b 20 c 30)

    Regards,

    Andrew.

Reply

  • The problem is that the variables arg1 and arg2 are out of scope when the body of the pcell is evaluated. You might think that you could solve this with SKILL++ (which has lexical scoping), but pcDefinePCell is not supported in SKILL++ (it can call SKILL++ functions, but can't be used in SKILL++ - mainly because the pcell wouldn't be able to store information about the lexical environment in which it was called). One way is to store the arguments on the cellView somewhere (as properties say), but another might just be to do:

    procedure(makeACell(arg1 arg2)
    eval(`pcDefinePCell(
      ...
      ...
      w=,arg1*,arg2
    ) ;pcDefinePCell
    ) ; eval
    ) ; procedure

    The quote before the pcDefinePCell is a backquote. This means that the code is not evaluated - but a list of the code - but rather than a normal quote, backquote allows selective evaluation. You precede the variable with a comma to selectively evaluate it.

    To illustrate what I mean:

    val1=20
    val2=30
    lst=`(a b ,val1 c ,val2)

    then lst will contain (a b 20 c 30)

    Regards,

    Andrew.

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