MUMPS can't format Number to String

Question

I am trying to convert larg number to string in MUMPS but I can't.

Let me explain what I would like to do :

s A="TEST_STRING#12168013110012340000000001"
s B=$P(A,"#",2)
s TAB(B)=1
s TAB(B)=1

I would like create an array TAB where variable B will be a primary key for array TAB.

When I do ZWR I will get

A="TEST_STRING#12168013110012340000000001"
B="12168013110012340000000001"
TAB(12168013110012340000000000)=1
TAB("12168013110012340000000001")=1

as you can see first SET recognize variable B as a number (wrongly converted) and second SET recognize variable B as a string ( as I would like to see ). My question is how to write SET command to recognize variable B as a string instead of number ( which is wrong in my opinion ).

Any advice/explanation will be helpful.

Answer 1

This may be a limitation of sorting/storage mechanism built into MUMPS and is different between different MUMPS implementations. The cause is that while variable values in MUMPS are non typed, index values are -- and numeric indices are sorted before string ones. When converting a large string to number, rounding errors may occur. To prevent this from happening, you need to add a space before number in your index to explicitly treat it as string:

s TAB(" "_B)=1

As far as I know, Intersystems Cache doesn't have this limitation -- at least your code works fine in Cache and in documentation they claim to support up to 309 digits:

http://docs.intersystems.com/cache20141/csp/docbook/DocBook.UI.Page.cls?KEY=GGBL_structure#GGBL_C12648

Answer 2

I've tried to recreate your scenario, but I am not seeing the issue you're experiencing. It actually is not possible ( in my opinion ) for the same command executed immediately ( one execution after another) to produce two different results.

s TAB(B)=1
s TAB(B)=1

for as long the value of B did not change between the executions, the result should be:

TAB("12168013110012340000000001")=1

Example of what GT.M implementation of MUMPS returns in your case