01083: Equation evaluations are more strictly enforced with BBj than BBx or P5

Title:

Equation evaluations are more strictly enforced with BBj than BBx or P5

Description:

The language parser in BBx and PRO/5 allows the following for comparison operators: 

<, >, = , <=, =>, <>, =<, >= 

Also, <=, =< AND =>, >= are considered equivalent operators. 
(Less Than OR Equal To; Equal To OR Less Than) 
(Equal To Or Greater Than; Greater Than OR Equal To) 

BBj does not support the use of => or =< so that we would have the option to use those as operators in the future. 

Here’s an example: 

On input, BBx accepts the following (technically incorrect) syntax: 

>10 le=(a=<b) 
>20 ge=(a=>b) 
>30 x=a(b) 

Internally, BBx always converts that syntax to: 

10 LET LE=(A<=B) 
20 LET GE=(A>=B) 
30 LET X=A[B] 

This internal format is the only syntax accepted by BBj. 

We dropped the questionable “feature” of a(b) being converted to a[b] because it creates a syntax ambiguity between arrays and functions and object expressions. 

This does create some conversion issues when you are converting ASCII programs to BBj, but tokenized BBx programs will always be in the correct format. 

Last Modified: 01/02/2006 Product: BBj Operating System: All platforms

BASIS structures five components of their technology into the BBx Generations.