6. Embedded QUEL for BASIC : EQUEL Statement Syntax for BASIC : BASIC Line Numbers and the EQUEL Mark
 
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BASIC Line Numbers and the EQUEL Mark
The BASIC line number, while not required, can occur at the beginning of most EQUEL statements before the EQUEL mark, ##. For example:
100  ##      destroy emp
The BASIC line number, if present, must be the first item on the line. It can be preceded only by spaces or tabs. The EQUEL ## mark must be the next item on the line after the optional line number and can be preceded by spaces or tabs. Any lines not marked by ## are treated as BASIC host code and are not preprocessed. Comments on lines not beginning with the ## mark are considered BASIC host code.
In most instances the preprocessor outputs any BASIC line numbers that precede an EQUEL statement. However, in a few cases the preprocessor ignores a BASIC line number and does not include it in the generated code. For example, line numbers occurring before EQUEL statements that produce no BASIC code are ignored by the preprocessor. Line numbers preceding EQUEL block statements, such as ## { and ## }, are also ignored. Line numbers should not occur on those lines containing a continued EQUEL string literal.
The preprocessor never generates line numbers of its own. Thus, if you prefix an EQUEL statement with a line number and that statement is translated by the preprocessor into several BASIC statements, the line number will appear before the first BASIC statement only. Subsequent BASIC statements will be unnumbered.
Note:  The BASIC language does require a line number on the first line of a program or subprogram. The EQUEL preprocessor does not verify that these line numbers exist.