Section 7: Introduction to TSP commands
Model DMM7510 7½ Digit Graphical Sampling Multimeter Reference Manual
7-26
DMM7510-901-01 Rev. B / May 2015
Tables and arrays
Lua makes extensive use of the data type table, which is a flexible array-like data type. Table indices
start with 1. Tables can be indexed not only with numbers, but with any value except
nil
. Tables can
be heterogeneous, which means that they can contain values of all types except
nil
.
Tables are the sole data structuring mechanism in Lua. They may be used to represent ordinary
arrays, symbol tables, sets, records, graphs, trees, and so on. To represent records, Lua uses the
field
name
as an index. The language supports this representation by providing
a.name
as an easier
way to express
a["name"]
.
The output you get from this example may vary depending on the data format settings of the
instrument.
Example: Loop array
atable = {1, 2, 3, 4}
i = 1
while atable[i] do
print(atable[i])
i = i + 1
end
Defines a table with four numeric elements.
Loops through the array and prints each
element.
The Boolean value of
atable[index]
evaluates to
true
if there is an element at that
index. If there is no element at that index,
nil
is
returned (
nil
is considered to be
false
).
Output:
1
2
3
4
Standard libraries
In addition to the standard programming constructs described in this document, Lua includes
standard libraries that contain useful functions for string manipulation, mathematics, and related
functions. Test Script Processor (TSP
®
) scripting engine instruments also include instrument control
extension libraries, which provide programming interfaces to the instrumentation that can be
accessed by the TSP scripting engine. These libraries are automatically loaded when the TSP
scripting engine starts and do not need to be managed by the programmer.
The following topics provide information on some of the basic Lua standard libraries. For additional
information, see the
http://www.lua.org
).
When referring to the Lua website, please be aware that the TSP scripting engine uses Lua 5.0.2.
