XPL Language Description

Comments:

<comment>           ::= <opening bracket> <almost anything> <closing bracket>

<opening bracket>   ::= /*

<closing bracket>   ::= */

<almost anything>   ::= {any string of valid characters which does not contain a <closing bracket>}

Text within comments is ignored, with one exception: a $ within a comment specifies that the next <character> is a control character. There are 256 control toggles corresponding to the 256 valid character codes. Each toggle can have a value true or false. When $<character> is encountered, the value of the corresponding toggle is complemented. Currently defined toggles are:

toggle Description initial

B Interlist emitted byte codes in hex. off

D Print statistics and symbol table. on

E Interlist emitted assembly code. off

L List compiled program. on

M List program without auxiliary information. off

N Warn if procedure args¬=parameters. off

S Dump symbol table at end of each procedure. off
T Begin tracing.

U Terminate tracing.

Z Allow program to execute in spite of errors. off

| Set margin. Input scan will be terminated at column containing the |