Scripting Guide - JMP

Chapter 2 JSL Building Blocks 33
The JSL Language
Names
A name is exactly what you think: something to call a thing. For example, when you assign the numeric
value 3 to a global variable in the statement a=3, “a” is a name. Commands and functions have names,
too. In the statement Log(4), the word “Log” is the name of JMP’s logarithm function. A name is any
language token that isn’t a number or a string or a special symbol operator (such as + or – or ++ or ^).
Names have a few rules:
• Names must start with an alphabetic character or underscore, and can continue with those as well as
numeric digits, spaces, tabs, vertical tabs, line and page delimiters, double-byte characters,
apostrophes, percent signs, periods, and backslashes:
a-z A-Z 0-9 _ ‘ % . \
• When comparing names, the white-space characters (like blanks, tabs, and newlines) are ignored,
and upper and lower case is not distinguished. For example the names Forage and for age are
equivalent.
2 JSL Building Blocks
Why does the language allow blanks inside names? Because it is good to have names of
commands and options be the same in the language as they are on the menus and
dialogs, and because people think in terms of multi-word names. The price of allowing
blanks is that JSL needs more delimiters, specifically commas and parentheses.
• Actually, you can still have a name that is any other sequence of characters, but if it doesn’t obey the
rules above, it needs to be quoted and placed inside a special parser directive called Name( ). For
example, to have a global variable with the name -)(*$%(*&$%A, you have to put it inside
quotation marks and Name( ) every time you use it in JSL:
Name("-)(*$%(*&$%A")=42;
foo=4; print(foo+Name("-)(*$%(*&$%A"));
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Name is harmless when it isn’t needed; for example, foo and Name("foo") are exactly the same
thing.
Numbers
Numbers can be written as integers, decimal numbers, in scientific notation with an E preceding the
power of ten, and as dates, times, or date/time values. A single period by itself is the missing numeric
value (sometimes called NAN for “not a number”).
For example, these are all numbers:
. 1 12 1.234 3E3 0.314159265E+1 1E-20
If you precede a number with a minus sign, the minus sign is usually interpreted as a prefix operator,
not part of the number. You can follow a number immediately with an E followed by a power of ten
you want to scale the number by. For example 3E2 means 3 times 10 to the power 2, or 300. If you
need a negative exponent of ten in E notation, that minus sign is part of the number.
Dates and times
JMP supports date/time values in a variety of common date/time notation formats. Date/time values are
stored and computed as a number of seconds since midnight, January 1, 1904. However, you can enter
a date/time value literally, using the format ddMonyyyy:hh:mm:ss.ddd, as in: