Initial revision

doc/occam/p4

@@ -0,0 +1,42 @@
+.NH
+Particular details
+.NH 2
+Lower case/Upper case
+.PP
+Keywords must be either fully written in lower case or in upper case, thus
+\fBPAR\fP is equivalent to \fBpar\fP but \fBPar\fP is not a keyword. Identifiers
+may be of mixed case. Different styles are used in our examples just to indicate
+what's accepted by the compiler.
+.NH 2
+File inclusion
+.PP
+The C preprocessor is applied to the input file before
+compilation, so that files containing useful \fBPROC\fP and \fBDEF\fP
+declarations can be used in your program by using the \fB#include\fP-directive
+of the preprocessor.
+.NH 2
+Substitution
+.PP
+Named processes are not textually substituted. A procedure call is used instead.
+The semantics of occam substitution imply this by letting a global variable
+(i.e. not declared inside the named process' body) be found where the named
+process is defined and not where it is substituted.
+.NH 2
+ANY
+.PP
+According to the occam syntax the \fBANY\fP keyword may be the only argument of
+an input or output process. Thus,
+.DS
+.ft 5
+	c ? ANY; x
+.ft
+.DE
+is not allowed. Because it was easy to add, and it was used by some programs,
+our compiler allows it. (If you prefer portability you are advised not to make
+use of it.)
+.NH 2
+Configuration
+.PP
+The special configuration keywords like \fBPLACED\fP, \fBALLOCATE\fP, \fBPORT\fP
+and \fBLOAD\fP are not implemented. Only \fBPRI\fP works because \fBPAR\fP and
+\fBALT\fP work the same without it.