| Chapter 4. Data Types, Values, and Ranges | ||
|---|---|---|
 | Part II. SIMPOL Language Basics |  |
Chapter 4. Data Types, Values, and Ranges
In this chapter we will discuss the various simple and complex data types
that are present in SIMPOL. We will also discuss the valid value ranges, the
special values .nul and .inf,
functions, supplied complex types, and user-defined types.
To start with, it is important to point out that in SIMPOL, everything is an
object. Types are objects, functions are objects, events are objects, and a
variable always refers either to an object or to .nul. The
scalar data types are also objects, but they are relatively simple objects. In
this chapter we will cover the SIMPOL scalar data types: blob,
boolean, integer, number, and
string. We will also cover some standard included object types:
array, date, datetime, and time.
Other types will be discussed in depth in their own chapters, such as file
streams, sockets, and databases.
Blobs
Blobs provide the SIMPOL programmer with a very powerful data type and mechanism for dealing with raw binary data. Blobs are also value types but they have a number of additional methods related to the ways in which they are most likely to be used.
It is probably easiest to think of blobs as being like a traditional array of
bytes and at the same time to be very similar in the way they work to strings.
Blobs can be concatenated using the + operator and then
assigned to a variable of type blob. The new blob will be the
combined length of the two original blobs. It is also possible to create a
blob with a pre-determined size. This can be a significant performance
improvement over strings, since it is possible to index into the blob using
the square brackets operators [] and to then modify the
value, whereas with a string concatenation would be used. When done once
there is no significant difference but in a loop, concatenation would result
in a large number of less efficient memory allocations that wouldn't have
been necessary in a blob.