4.3BSD/usr/doc/ps2/07.fp/manApp.rno

.\" Copyright (c) 1980 Regents of the University of California.
.\" All rights reserved.  The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\"
.\"	@(#)manApp.rno	6.2 (Berkeley) 5/10/86
.\"
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.AP "Appendix A: Local Modifications"
.NS 1 "Character Set Changes"
.sp
.pp
Backus [Ba78] used some
characters that do not appear on our
ASCII terminals, so  we have made the following substitutions:
.sp 2
.TS
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l|c|c.
\fBconstant\fP	 $x bar$	%\fIx\fP
\fBinsert\fP	\(sl	!
\fBapply-to-all\fP	\(*a	&
\fBcomposition\fP	\*(cm	@
\fBarrow\fP	$->$	->
\fBempty set\fP	\(*f	<>
\fBbottom\fP	\*(bt	?
\fBdivide\fP	\(di	\(sl
\fBmultiply\fP	\(mu	\(**
.TE
.sp
.NS 1 "Syntactic Modifications"
.NS 2 "While and Conditional"
.pp
\fBWhile\fP and conditional functional expressions
\fImust\fP be enclosed in parenthesis, \*(EG
.sp
.(c
(\fBwhile\fP \fIf g\fP)
.sp
(\fIp\fP \fB->\fP \fIf\fP \fB;\fP \fIg\fP)
.)c
.sp
.NS 2 "Function Definitions"
.pp
Function definitions are 
enclosed by curly braces; they
consist of a name-definition pair,
separated by blanks.  For example:
.sp
.ce 1
.b "{fact$~$ !\(** @ iota}"
.sp
defines the function \fBfact\fP (the reader should recognize this as the
non-recursive factorial function).
.sp
.NS 2 "Sequence Construction"
.pp
It is not necessary to  separate elements of a sequences with
a comma; a blank will suffice:
.sp
.nf
.ce 1
<1,2,3> $==$ <1 2 3>
.sp
.fi
.pp
For nested sequences, the terminating right angle bracket
acts as the delimiter:
.sp
.nf
.ce 1
<<1,2,3>,<4,5,6>> $==$ <<1 2 3><4 5 6>>
.sp
.fi
.sp 2
.NS 1 "User Interface"
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.pp
We have provided a rich set of commands that allow the user to
catalog, print, and
delete functions, to load them from a file and to save them away.
The user may generate script files, dynamically trace and
measure functional expression execution, generate debugging output,
and, temporarily exit to the \s-2FRANZ LISP\s+2 system.
A command must begin with a right parenthesis.  
Consult Appendix C for a complete description of the command syntax.
.pp
Debugging in FP is difficult;
all undefined results map to a single
atom \- \fIbottom\fP (\*(lq?\*(rq).
To pinpoint the cause of an error the user can use
the special debugging output function, \fBout\fP, or the tracer.
.sp
.NS 1 "Additions and Ommissions"
.sp
.pp
Many relational functions have been added: $<,~~>,~~=,~~ \(!=, ~~<=,~~>=$;
their
syntax is: <, >, =, ~=, <=, >=.
Also added are the \fBiota\fP function (This is the \s-2APL\s+2
iota function
an n-element sequence
of natural numbers) and the exclusive OR (\z\(ci\(pl) function.
.pp
Several new structural functions have been added:  \fBpair\fP
pairs up successive elements of a sequence, \fBsplit\fP splits
a sequence into two (roughly) equal halves, \fBlast\fP returns
the last element of the sequence (<> if the sequence is empty),
\fBfirst\fP returns the first element of the sequence
(<> if it is empty), and \fBconcat\fP
concatenates all subsequences of a sequence, squeezing out null sequences (<>).
\fBFront\fP is equivalent to \fBtlr\fP.
\fBPick\fP is a parameterized form of
the selector function; the first component of the argument selects
a single element from the second component.
\fBOut\fP is the only side-effect function; it is equivalent
to the \fBid\fP function but it also prints its argument out at the
terminal.  This function is intended to be used only for debugging.
.pp
One new functional form has been added, tree insert.  This
functional form breaks up the the argument into two roughly equal pieces
applying itself
recursively to the two halves.  The functional parameter is applied to the
result.
.pp
The binary-to-unary functions ('\fBbu\fP') has been omitted.
.pp
Seven mathematical library functions have been added: sin, cos, asin
($sin sup {-1}$), acos ($cos sup {-1}$), log, exp, and mod (the
remainder function)
.bp
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.nf
.nr ii 18
.AP "Appendix B: FP Grammar"
\fII. BNF Syntax\fP
.sp
.ip "fpInput $->$"
(fnDef | application | fpCmd\*(sa)\(**  | '^D'
.ip "fnDef $->$"
\&'{' name funForm '}'
.ip "application $->$"
funForm ':' object
.ip "name $->$"
letter (letter | digit | '_')\(**
.ip "nameList $->$"
(name)\(**
.ip "object $->$"
atom | fpSequence | '?'
.ip "fpSequence $->$"
\&'<' (\(*e | object ((',' | ' ') object)\(**) '>'
.ip "atom $->$"
\&'T' | 'F' | '<>' | '"' (ascii-char)\(** '"' | (letter | digit)\(** | number
.ip "funForm $->$"
simpFn	| composition | construction | conditional |
.br
constantFn | insertion | alpha | while | '(' funForm ')'
.ip "simpFn $->$"
fpDefined | fpBuiltin
.ip "fpDefined $->$"
name
.ip "fpBuiltin $->$"
selectFn | 'tl' | 'id' | 'atom' | 'not' | 'eq' | relFn | 'null' | 'reverse' |
.br
\&'distl' | 'distr' | 'length' | binaryFn | 'trans' | 'apndl' | 'apndr' |
.br
\&'tlr' | 'rotl' | 'rotr' | 'iota' | 'pair' | 'split' | 'concat' | 'last' | 'libFn'
.ip "selectFn $->$"
(\(*e | '+' | '-') unsignedInteger
.ip "relFn $->$"
\&'<=' | '<' | '=' | '~=' | '>' | '>='
.ip "binaryFn $->$"
\&'+' | '-' | '\(**' | '/' | 'or' | 'and' | 'xor'
.ip "libFn $->$"
\&'sin' | 'cos' | 'asin' | 'acos' | 'log' | 'exp' | 'mod'
.ip "composition $->$"
funForm '@' funForm
.ip "construction $->$"
\&'[' formList ']'
.ip "formList $->$"
\(*e | funForm (',' funForm)\(**
.ip "conditional $->$"
\&'(' funForm '->' funForm ';' funForm ')'
.ip "constantFn $->$"
\&'%' object
.ip "insertion $->$"
\&'!' funForm | '\fB|\fP' funForm
.ip "alpha $->$"
\&'&' funForm
.ip "while $->$"
\&'(' 'while' funForm funForm  ')'
.sp
.lp
.nf
\fIII. Precedences\fP
.sp
1.	%, !, &	 		(highest)
2.	@
3.	[$...$]
4.	-> $...$ ; $...$
5.	while			(least)
.(q
.sp 2
\*(sa Command Syntax is listed in Appendix C.
.)q
.fi
.AP "Appendix C: Command Syntax"
.pp
All commands begin with a right parenthesis (\*(lq)\*(rq).
.sp 2
.nf
)fns
)pfn <nameList>
)load <UNIX file name>
)cload <UNIX file name>
)save <UNIX file name>
)csave <UNIX file name>
)fsave <UNIX file name>
)delete <nameList>
)stats on
)stats off
)stats reset
)stats print [UNIX file name]
)trace on  <nameList>
)trace off <nameList>
)timer on
)timer off
)debug on
)debug off
)script open <UNIX file name>
)script close
)script append <UNIX file name>
)help
)lisp
.EQ
delim `'
.EN
.AP "Appendix D: Token-Name Correspondences"
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Token	Name
=
\&[	lbrack$$
\&]	rbrack$$
\&{	lbrace$$
\&}	rbrace$$
\&(	lparen$$
\&)	rparen$$
\&@	compos$$
\&!	insert$$
\&\fB|\fP	ti$$
\&&	alpha$$
\&;	semi$$
\&:	colon$$
\&,	comma$$
\&+	builtin$$
\&+ `mu sup a'	select$$
\&\(**	builtin$$
\&/	builtin$$
\&=	builtin$$
\&-	builtin$$
\&->	arrow$$
\&- `mu'	select$$
\&>	builtin$$
\&>=	builtin$$
\&<	builtin$$
\&<=	builtin$$
\&~=	builtin$$
\&%`omicron sup b'	constant$$
.TE
.sp 2
.(q
\*(sa \(*m is an optionally signed integer constant.
.sp
\*(sb \(*o is any FP object.
.)q
.AP "Appendix E: Symbolic Primitive Function Names"
.pp
The scanner assigns names to the alphabetic primitive functions by
appending the string \*(lq$fp\*(rq to the end of the function name.
The following table designates the
naming assignments to the non-alphabetic primitive function names.
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Function	Name
=
\&+	plus$fp
\&-	minus$fp
\&\(**	times$fp
\&/	div$fp
\&=	eq$fp
\&>	gt$fp
\&>=	ge$fp
\&<	lt$fp
\&<=	le$fp
\&~=	ne$fp
.TE
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