ans-diff.md

Typeforth Differences with ANS Forth

The primary high level differences are:

• supports modules (namespace), sumtypes (variadic enums), prodtypes (structs) and vtables (interfaces)
• naming is more modern and consistent. I.e. .stack prints the stack and .ix prints an integer as hex. All "print" operations are of the form .XXX. Also, using "type" is out of the question as it normally refers to a data-type so would be extremely confusing.
• More compatible across architectures -- most types are not dependent on the cell size.
• Supports different sizes for code and data (i.e. 16 bit code pointer, 32 bit data pointer), enabling more compact code if there is less that 64k of code.

Description	TF Type	ANS Type	Reason
unsigned 8 bits of data	b, byte	c, char
8 bit ascii value	ascii	c, char	TF "char" reserved for unicode
signed 8 bits of data	sb, sbyte	?
unsigned 16 bits of data	i, int	u iff 16bit cell, else ?	in TF "i" always representes 16 bit integer
signed 16 bits of data	si, sint	i iff 16bit cell, else ?
unsigned 32 bits of data	d, double	d if 16 bit cell else u if 32 bit cell	in TF "d" always represents 32 bit integer
signed 32 bits of data	sd, sdouble	i if 32 bit cell else ?
data address (pointer)	&	addr
byte address	&b	c-addr
8 bit data access	b@	c@
16 bit data access	i@	@ if 16 bit cell else ?
32 bit data access	d@	@ if 32 bit cell else ?
executable code	x	code point
executable code address	&x	xt	Note: also called an "execution token". TF supports different code/data address sizes
code address access	x@	@
module/method/vtable access	.	N/A	TF supports modules, methods and vtables
( byte-address count ) string	s	( c-addr count )	TF has specific name for strings
print string to stderr	.s	type
print signed 16 bit integer as hex	.six	. if HEX and 16 bit cell	Note: TF doesn't append spaces like ANS does.
print unsigned 16 bit integer as hex	.ix	u. if HEX and 16 bit cell	ANS inconsistent with where the . goes, TF always has . first
print stack to stderr	.stack	.s if HEX and 16 bit cell
string literal	\" ...\"	\" ..."	TF uses \" for both opening and closing, allowing nested "
formatted string literal	\" .. $word \"	??	TF allows string formatting with arbitrary embedded expressions.