.\" @(#)hpg.1	1.9 dated 92/07/20 at 17:30:33
.TH HPG 1 92/07/20
.SH NAME
hpg \- generate random Haskell programs to test compilers
.SH SYNOPSIS
.B hpg
[
.B \-s
seeds ] [
.B \-nt
types ] [
.B \-dt
type_depth ] [
.B \-nv
values ] [
.B \-dv
val_depth ] [
.B \-de
exp_depth ] [
.B \-m
mod_name ] [
.B \-o
file ]
.SH DESCRIPTION
.I hpg
generates self-checking random test Haskell programs.
These are designed to test the code generation part of a compiler; when
executed they should print a list of
.IR True s.
An
.I hpg
program consists of a sequence of algebraic type declarations, a
sequence of value declarations and then a
.I main
function which checks that the declared values are equal to specially
generated expressions.
.SH ARGUMENTS
.TP
.BI \-s " seeds"
Provides seeds for the internal random number generator.
.I seeds
should be of the form
.I '(n1,n2,n3)'
where
.IR n1 ,
.IR n2 ", and"
.IR n3
are integers, and the quotes protect the parentheses
from shell interpretation.
.TP
.BI \-nt " types"
The number of algebraic type declarations to be generated.
.TP
.BI \-dt " type_depth"
An integer giving a measure of the complexity of the generated types.
.TP
.BI \-nv " values"
The number of value declarations to be generated.
.TP
.BI \-dv " val_depth"
An integer giving a measure of the complexity of the generated values.
.TP
.BI \-de " exp_depth"
An integer giving a measure of the complexity of the generated expressions.
.TP
.BI \-m " mod_name"
Name of the module to which the output module will be written.
.TP
.BI \-o " file"
Name of a file to which the output program will be written.
In the absence of this flag, the program is written to the standard
output.
.TP
.BI \-?
any flag value not in the above list causes
.I hpg
to generate a message giving the default values of all flags.
.SH NOTES
.I hpg
is under continuous development and, I hope, improvement.
Comments, suggestions and bug reports are always welcome \- please send
them to the email address at the end of this manual page.
.SH "SEE ALSO"
.I The Haskell Program Generator.
Commented source code for
.IR hpg .
.SH AUTHOR
.I hpg
was written by Nick North, of the National Physical Laboratory, UK.
Email address:
.IR ndn@seg.npl.co.uk .