Intel XENIX 286 Programmers Guide (86) - Tenox.tc

as: A sse m bier XENIX Programming
Lexica l Conventions
This section describes as lexical conventions for identifiers, constants, white space, and
comments.
Identifiers
An identifier consists of a sequence of alphanumeric characters, including periods (.) and
underscores (_) . The first character must not be numeric. By convention, the first eight
characters are significant, but you can also define the maximum number of significant
characters by using the -nl option. Uppercase and lowercase letters are considered
distinct in identifiers.
Constants
A hex constant consists of a slash character (/) followed by a sequence of digits and one
of the letters "a", "b", "c", "d", "e", or "f", any of which may be capitalized.
A decimal constant consists simply of a sequence of digits. The constant should be
representable in 15 bits, i.e., be less than 32,768.
A character constant consists of one or two characters enclosed in single quotation
marks ('). If a single quotation mark is used in a constant, it must be given twice to
represent a single occurrence (").
The following are examples of constants:
Decimal
10
32767
White Space
Hexadecimal
/1b
/7fff
Character
'a'
'in'
Blank and tab characters may be freely interspersed between tokens but may not be
used within tokens (except in character constants). A blank or tab is required to
separate adj acent identifiers or constants not otherwise separated.
Comments
The vertical bar (I) introduces a comment, which extends to the end of the line where it
appears. Comments are ignored by the assembler.
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