32-bit transition
The most critical issue facing the computer industry in the 1990s is the transition from
16-bit computing to 32/64-bit computing. 16-bit architecture, inherent in DOS and
Intel 80x86 CPUs prior to the 80386 held back software progress for quite some time.
But users will not move to 32-bit and 64-bit systems until the transition is
relatively painless. XBasic helps makes the transition a pleasure for BASIC
programmers, the largest group of programmers worldwide.
architecture
XBasic runs only on 32-bit and 64-bit computers. It is free of the numerous
complexities, difficulties, and implementation/architecture dependencies that other
computer languages could not avoid, given the era in which they developed.
XBasic programs and data can grow to gigantic proportions, and programs from one line to
one million lines work identically. There's only one memory model, full 32/64-bit.
And since XBasic runs only under virtual memory operating systems, programs can greatly
exceed the size of system memory.
clean slate design
XBasic was developed from a clean slate. It does not propagate awkward syntax from
earlier BASICs in an attempt at strict upward compatibility. XBasic was designed to
be clean, simple, consistent, readable, and intuitive. As a result of the
clean-slate approach, XBasic programmers are not saddled with the needless complexity and
limited functionality of previous BASICs.
structured programming
XBasic is a structured programming language. Structure is a form of visual and
functional encapsulation in which multiple-line sections of program look and act like
single units. The beginning and end of blocks are marked by descriptive keyword
delimiters. Lines within blocks are generally indented to make the block visible.
encapsulation
Encapsulation is a way of reducing complexity in large programs by building them from
small to medium size pieces. Encapsulation reduces the number of connections between
the pieces, organizes those that remain, and encourages proper documentation of the
connections. Functions and user-defined types are the chief means of encapsulation
in XBasic.
Fully encapsulated functions perform specific, limited, easily graspable action while
having no other effects. Once written, they can be used and reused without
consideration of their implementation.
XBasic programs can be written with nothing but fully encapsulated functions, but shared
variables are occasionally necessary. In XBasic, shared and external variables are
declared in SHARED or EXTERNAL statements. These statements, which are the first
lines within functions, consolidate and make visible the ways the functions are vulnerable
to outside influence.