Expressions

The MPL macro processor interprets balanced text strings as numeric expressions when they are used arguments to the following MPL functions:

• EVAL
• IF
• REPEAT
• SUBSTR
• WHILE

Numeric expressions are processed as follows:

1. The text of the expression is expanded in the ordinary manner in which macro function arguments are evaluated.
2. The resulting string is evaluated to a numeric value which is converted into a character representation of the expression's value (which is the final value of the expression).

The following operators may be used in numeric expressions:

• Parentheses ()
• HIGH, LOW
• *, /, MOD, SHL, SHR
• EQ, LT, LE, GT, GE, NE
• NOT
• AND, OR, XOR

Arithmetic on MPL numeric expressions is performed using signed 16-bit integers. The result of relational operators is either 0 (FALSE) or 1 (TRUE).

Numeric Constants

Numbers may be specified in hexadecimal (base 16), decimal (base 10), octal (base 8), and binary (base 2) using the suffix and character specified in the following table:

A number with no explicit base is interpreted as a decimal number. The first character of a number must always be a digit (0-9). Hexadecimal numbers that do not have a digit as the first character — that is, if they have A-F in that position — must be prefixed with a 0.

Dollar sign characters ('$') may be used within numbers to make them more readable. However, the dollar sign may not be the first or last character of a number. For example:

Hexadecimal numbers may be entered using C language conventions.

Character Constants

The MPL macro processor supports ASCII character strings which may consist of one or two characters enclosed in single quotes ("'"). For example:

Note

• The macro processor cannot access the assembler's symbol table. Therfore, the values of labels and of SET and EQU symbols are not known during macro processing. However, you may use the SET macro function to define macro symbols.