###############################################################################
#                                                                             #
#  Lout @GraphMath package for @Graph (Version 1.1)                           #
#                                                                             #
#  Version 1.0 by Jeffrey H. Kingston, December 1993.                         #
#  Version 1.1 by Jeffrey H. Kingston, October 1996.                          #
#                                                                             #
#  This package provides mathematics for the @Graph graph drawing package.    #
#                                                                             #
###############################################################################

export

    "-0" "-1" "-2" "-3" "-4" "-5" "-6" "-7" "-8" "-9" "-."
    pi e sqrt abs ceiling floor truncate round cos sin atan
    exp log rand "*" "/" idiv mod "+" "-"
    "=" "!=" "<" "<=" ">" ">=" not and xor or
    if xloop yloop zloop

def @GraphMath
{
    def "-0" { "-0" }
    def "-1" { "-1" }
    def "-2" { "-2" }
    def "-3" { "-3" }
    def "-4" { "-4" }
    def "-5" { "-5" }
    def "-6" { "-6" }
    def "-7" { "-7" }
    def "-8" { "-8" }
    def "-9" { "-9" }
    def "-." { "-." }

    def pi { "3.14159" }

    def e  { "2.71828" }

    def sqrt
	precedence 40
	right y
    {
	y "sqrt"
    }

    def abs
	precedence 40
	right y
    {
	y "abs"
    }

    def ceiling
	precedence 40
	right y
    {
	y "ceiling"
    }

    def floor
	precedence 40
	right y
    {
	y "floor"
    }

    def truncate
	precedence 40
	right y
    {
	y "truncate"
    }

    def round
	precedence 40
	right y
    {
	y "round"
    }

    def cos
	precedence 40
	right y
    {
	y "cos"
    }

    def sin
	precedence 40
	right y
    {
	y "sin"
    }

    def atan
	precedence 39
	left x
	right y
    {
	x y "atan"
    }

    def exp
	precedence 38
	left x
	right y
    {
	x y "exp"
    }

    def log
	precedence 37
	left x
	right y
    {
	x y "dolog"
    }

    def rand
	precedence 36
	left x
	right y
    {
	x y "dorand"
    }

    def "*"
	precedence 35
	left x
	right y
    {
	x y "mul"
    }

    def "/"
	precedence 35
	left x
	right y
    {
	x y "div"
    }

    def "idiv"
	precedence 34
	left x
	right y
    {
	x y "idiv"
    }

    def "mod"
	precedence 34
	left x
	right y
    {
	x y "mod"
    }

    def "-"
	precedence 33
	left x
	right y
    {
	x @Case {
	    ""   @Yield { y "neg" }
	    else @Yield { x y "sub" }
	}
    }

    def "+"
	precedence 32
	left x
	right y
    {
	x @Case {
	    ""   @Yield { y }
	    else @Yield { x y "add" }
	}
    }

    def "="
	precedence 30
	left x
	right y
    {
	x y "eq"
    }

    def "!="
	precedence 30
	left x
	right y
    {
	x y "ne"
    }

    def "<"
	precedence 30
	left x
	right y
    {
	x y "lt"
    }

    def "<="
	precedence 30
	left x
	right y
    {
	x y "le"
    }

    def ">"
	precedence 30
	left x
	right y
    {
	x y "gt"
    }

    def ">="
	precedence 30
	left x
	right y
    {
	x y "ge"
    }

    def "not"
	precedence 25
	right y
    {
	y "not"
    }

    def "and"
	precedence 24
	left x
	right y
    {
	x y "and"
    }

    def "xor"
	precedence 23
	left x
	right y
    {
	x y "xor"
    }

    def "or"
	precedence 22
	left x
	right y
    {
	x y "or"
    }

    def if
	named cond { true }
	named then {}
	named else {}
    {
	cond "{" then "} {" else "} ifelse"
    }

    def xloop
	named from { 0 }
	named to { 0 }
	named by { 1 }
	named do named x { "xval" } {}
    {
	from by to "{ /xval exch def" do "} for"
    }

    def yloop
	named from { 0 }
	named to { 0 }
	named by { 1 }
	named do named y { "yval" } {}
    {
	from by to "{ /yval exch def" do "} for"
    }

    def zloop
	named from { 0 }
	named to { 0 }
	named by { 1 }
	named do named z { "zval" } {}
    {
	from by to "{ /zval exch def" do "} for"
    }

}