.so tmac.ilib
.TH PDAE 2 "The University of Arizona \- 8/16/84"
.SH NAME
pdae \- programmer-defined argument evaluation
.SH DESCRIPTION
These procedures are taken mainly from TR 82-16, which describes
how co-expressions can be used to model the built-in argument
evaluation regime of Icon and also provide new ones. Some procedures have
been corrected or improved.
.SH SYNOPSIS
.nf
.ta 2.0i
\*MAllpar\^{e1,\*be2,\*b \*(El}\fR	parallel evaluation with last result used for short sequences
\*MCall(a)\fR	utility procedure to call functions
\*MExtract\^{e1,\*be2, \*(El}\fR	extract results of even-numbered arguments according to
	   odd-numbered values
\*MLifo\^{e1,\*be2, \*(El}\fR	models standard Icon `lifo' evaluation
\*MParallel\^{e1,\*be2, \*(El}\fR	parallel evaluation terminating on shortest sequence
\*MReverse\^{e1,\*be2, \*(El}\fR	left-to-right reversal of lifo evaluation
\*MRotate\^{e1,\*be2, \*(El}\fR	parallel evaluation with shorter sequences re-evaluated
\*MSimple\^{e1,\*be2, \*(El}\fR	simple evaluation with only success or failure
.SH REQUIREMENTS
\fIPdae\fR requires the experimental extensions in Version 5.9 of Icon.
.SH BUGS AND LIMITATIONS
Because of the handling of the scope of local identifiers in co-expressions,
expressions in programmer-defined argument evaluation regimes cannot communicate
through local identifiers. The results produced by programmer-defined
argument evaluation regimes are always dereferenced. Some constructions, such
as \*Mbreak\fR and \*Mreturn\fR, cannot be used in arguments to programmer-defined
argument evaluation regimes. See TR 82-8 for details of these problems.
.PP
At most 10 arguments can be used in the invocation of a programmer-defined
argument evaluation regime. This limit can be increased by
modifying \*MCall\fR.
.SH SEE ALSO
pdco(2)
.PP
.Pd
.PP
Novak, Michael and Ralph E. Griswold. \fIProgrammer-Defined Argument
Evaluation Regimes\fR, TR 82-16,
Department of Computer Science, The University of Arizona, 1982.
.PP
.Ex
.SH AUTHORS
Ralph E. Griswold and Michael Novak