BISL Language Summary
Simon D. Levy
Computer Science Department
Brandeis University
Waltham, MA 02254
levy@cs.brandeis.edu

Reserved Words

	back	circ	click	dclick	giff
	image	place	rect	roll    sound
	string	text	tog


Comments

# This is a BISL comment.  It can begin anywhere, and ends at the newline.


Literals

number				Type int

'characters'			Type string

characters://characters		Type URL 

letters,numbers,\_,-,.		Type filename

(System-dependent)		Type font

PLAIN, BOLD, ITALIC		Type style

white, black, lightGray,	Type color
darkGray, red, green, blue,
yellow, magenta, cyan, pink,
orange				


Statements

Tuples

Format
id < name (args)

Names/Args


circ(center_X, center_Y, radius [,placement_id])

giff(filename)

place(id, uppler_left_X, uppler_left_Y [,depth])

rect(upper_left_X, upper_left_Y, lower_right_X, lower_right_Y [,placement_id])

string(string, [font], [style], [size], [color])

Constraint nodes

Format
id = name(arg)


where arg is a circ, rect, or place tuple identifier

Names

click()    dclick()    roll()


Substantive nodes

Format
name(arg [,constraint])

where constraint is a Boolean expression over edge identifiers,
using & for AND, | for OR, ^ for XOR, and ~ for NOT. Precedence is NOT > AND > (X)OR; 
parentheses may be used to override this order.

Names/Args

back(giff_id)   image(place_id)   sound(filename)   text(string_id)   URL(url)


Input-output nodes

Format
id = name(arg)

where arg is a constraint-node identifier

Names

tog()