Assigned variables and batch purge (CAS utility functions)

+- HP Forums (https://www.hpmuseum.org/forum)
+-- Forum: HP Software Libraries (/forum-10.html)
+--- Forum: HP Prime Software Library (/forum-15.html)
+--- Thread: Assigned variables and batch purge (CAS utility functions) (/thread-13816.html)

Assigned variables and batch purge (CAS utility functions) - dae - 10-17-2019 04:17 PM

Here are a three CAS utility functions. Two of them, varslist1() and varslist2(), identify assigned variables, showing type and value. The third can be used to batch purge single-character lower-case variables.


A. varslist1() identifies a-z variables which have been assigned values. It shows the variable type and the value.
Code:

#cas
// Identifies lower-case one-letter variables
//   such as "a", "b", etc.
// Must run from CAS side
// It's a function, so it needs empty "()"s, i.e., varslist1() 

varslist1():=
BEGIN
local mylist, myindex;
mylist := "abcdfghjklmnopqrstuvwxyz";
print("assigned lower-case one-letter vars"); 
for myindex from 1 to length(mylist) do
  //DOM_IDENT = 6
  if type(expr(mylist[myindex])) != 6 then
    print(mylist[myindex] + ": " +
    type(expr(mylist[myindex]))); 
    print(expr(mylist[myindex])); 
  end;
end;
print("**end of list**");
END;
#end

B. varslist2() is not limited to one-character variables. You can include any variable names by adding them to the mylist variable. Place the variable name in quotes and separate with a comma. Your variables can be placed anywhere in the list.
Code:

#cas
// This version allows for any-length variables
//   just add them to mylist, inside double quotes, separated by comma 
// Must run from CAS side
// It's a function, so it needs empty "()"s, i.e., varslist2()

varslist2():=
BEGIN
local mylist, myindex;
//this example has added x1, x2, E1, and X to mylist
//modify mylist as you see fit
mylist := ["a","b","c","d","f","g","h","j","k","l",
           "m","n","o","p","q","r","s","t","u","v",
           "w","x","y","z",
           "x1","x2","E1","X"];  //edit this variable
print("varslist2: mylist vars assigned values"); 
for myindex from 1 to length(mylist) do
  //DOM_IDENT = 6
  if type(expr(mylist[myindex])) != 6 then
    print(mylist[myindex] + ": " +
    type(expr(mylist[myindex]))); 
    print(expr(mylist[myindex])); 
  end;
end;
print("**end of list**");
END;
#end

C. purgeaz() clears the values from small a to small z (e and i are reserved and ignored)
Code:

#cas
//  purgeaz(): purge all single small-letter variables
//  excludes e and i, which are reserved anyway
//  Run from CAS side
//  it's a CAS function call,  i.e. purgeaz()
purgeaz():=
BEGIN
purge([a,b,c,d,f,g,h,j,
       k,l,m,n,o,p,q,r,s,t,
       u,v,w,x,y,z]);
return("Vars a to z have been purged");
END;
#end