add existing documentation

doc/example.asm

@@ -0,0 +1,241 @@
+@msgh (net.doorstuck.test.Person) [-init(name:age:)]
+	ldr x0, [bp, #-1]
+	str x0, [self, #0]
+
+	ldr x0, [bp, #-2]
+	str x0, [self, #1]
+
+	ret
+@end
+
+@msgh (net.doorstuck.test.Person) [-name]
+	ldr x0, [self, #0]
+
+	ret
+@end
+
+
+@msgh (net.doorstuck.test.Person) [-age]
+	ldr x0, [self, #1]
+
+	ret
+@end
+
+@msgh (net.doorstuck.test.Person) [-ageInMonths]
+	ldr x0, [self, #1]
+	ldr x1, #12
+	mul x0, x0, x1
+
+	ret
+@end
+
+@msgh (net.doorstuck.test.Person) [-setName:]
+	ldr x0, [bp, #-1]
+	str x0, [self, #0]
+
+	ret
+@end
+
+@msgh (net.doorstuck.test.Person) [-setAge:]
+	ldr x0, [bp, #-1]
+	str x0, [self, #1]
+
+	ret
+@end
+
+@msgh (net.doorstuck.test.Person) [-setAge:in:]
+	ldr x0, [bp, #-1]
+
+	ldr x1, "years"
+	cmp x0, x1
+	b.eq $L0001
+
+	ldr x1, "months"
+	cmp x0, x1
+	b.eq $L0002
+
+	ldr x1, "days"
+	cmp x0, x1
+	b.eq $L0003
+
+	; else
+	ldr x2, #0
+	str x2, [self, #1]
+	br $L0004
+
+	; if units == "years"
+L0001:  str x0, [self, #1]
+	br $L0004
+
+	; if units == "months"
+L0002:  ldr x2, #12
+	div x0, x0, x2
+	str x0, [self, #1]
+	br $L0004
+
+	; if units == "days"
+L0003:  ldr x2, #365
+	div x0, x0, x2
+	str x0, [self, #1]
+
+	; end
+L0004:
+	ret
+@end
+
+@lambda (Lx0001) [_:]
+	ldr x1, @ident[cout]
+	ldr x2, [bp, #-1]
+
+	ldr x3, "Count is "
+	add x3, x3, x2
+
+	push x3
+	msg x1, @selector[-put:]
+
+	ret
+@end
+
+@lambda (Lx0002) []
+	ldr x1, @ident[cout]
+
+	ldr x2, "True!"
+	push x2
+
+	msg x1, @selector[-put:]
+@end
+
+@lambda (Lx0003) []
+	ldr x1, @ident[cout]
+
+	ldr x2, "False!"
+	push x2
+
+	msg x1, @selector[-put:]
+@end
+
+@init
+	rsv #3 		; 3 local variables
+	/* stack layout is now this:
+		bp[1] = p1
+		bp[2] = i
+		bp[3] = j
+	*/
+
+	; p1 = Person new(name:"John Doe", age:34)
+	ldr x0, #34
+	push x0
+
+	ldr x0, "John Doe"
+	push x0
+
+	ob.c x1, x1
+	msg x1, @selector[-init(name:age:)] 	; x0 = new Person object
+	str x1, [bp, #1] 	; p1 = new Person object
+
+	; p1 setAge:100 in:"months"
+
+	; p1 is already loaded in x1, no need to load it again
+	ldr x2, @selector[-setAge:in:]
+
+	ldr x3, "months"
+	push x3
+
+	ldr x3, #100
+	push x3
+
+	msg x1, @selector[-setAge:in:]	; x0 = null
+
+	ldr x3, #0
+	str x3, [bp, #2] 		; i = 0
+
+	; (while i < 10) begin
+L0001:  ldr x2, @ident[cout] 		; x5 = cout
+	ldr x4, "Count is "
+
+	add x4, x4, x3 			; append i (in x4) to "Count is " (in x7)
+
+	push x4
+	msg x2, @selector[-put:]
+
+	add x3, x3, #2
+
+	cmp x3, #100
+	b.lt $L0001
+	; (while i < 0) end
+
+	; for i in 0 to:100 step:2
+	ldr x4, #2
+	push x4
+
+	ldr x4, #100
+	push x4
+
+	ldr x4, #0
+	
+	msg x5, @selector[-to:step:]
+	mov x5, x0 			; x5 = (0 to:100 step:2) -> iterator
+
+	; (for i in 0 to:100 step:2) begin
+L0002:  it.v x5 			; is iterator still valid?
+	b.z $L0003
+
+	it.g x4, x5 			; get current iterator value
+	
+	ldr x6, "Count is "
+	add x6, x6, x4 			; append i (in x4) to "Count is " (in x6)
+
+	ldr x7, @ident[cout]
+
+	push x6
+	msg x7, @selector[-put:]
+
+	it.n x5 			; Advance iterator
+	br $L0002
+	; (for i in 0 to:100 step:2) end
+
+L0003:  ob.e x5 			; Clean up iterator
+
+	lam.c x5, @lambda[Lx0001] 			; x5 = [ _:i | cout put:'Count: {i}' ],
+
+	push x5
+
+	ldr x5, #2
+	push x5
+
+	ldr x5, #100
+	push x5
+
+	ldr x5, #0
+	msg x5, @selector[-to:step:do:]
+
+	ldr x5, #32
+	str x5, [bp, #3] 	 	; (x5) j = 32
+
+	ldr x6, [bp, #1] 		; (x6) i
+
+	c.lt x5, x6, x5
+	
+	lam.c x6, @lambda[Lx0003]
+	push x6
+
+	lam.c x6, @lambda[Lx0002]
+	push x6
+
+	msg x5, @selector[-if:else:]
+
+	ldr x5, [bp, #2] 		; (x5) j
+	ldr x6, [bp, #1] 		; (x6) i
+
+	cmp x6, x5
+	b.ge $L0004
+
+	ldr x5, "True!"
+	push x5
+
+	ldr x5, @ident[cout]
+
+	msg x5, @selector[-put:]
+
+L0004:	ret
+@end