Extraordinary String Animals - Revision history

Jhoger: Reverted edits by Shaina (Talk); changed back to last version by Ronw

2010-06-05T23:50:49Z

Reverted edits by Shaina (Talk); changed back to last version by Ronw

New page

Ron Wiesen, in response to a question from Wilson Van Alst:

To your first question: the situation of $trings (i.e., where they sit) in
the $tring-space can set the stage for a compelled 'garbage collection' that
takes place, as a neccessary prelude, to a subsequent $tring operation. In
other words, the $tring-space holds existing $trings which are not adjoined
(unused gaps of space are between $trings) and then the BASIC interpreter
encounters some $tring operation. The total volume of unused $tring-space
is sufficient to support the $tring operation. But that total is fragmented
due to the way existing $trings are situated in the $tring-space. This
compels the BASIC interpreter to suspend interpretation, conduct 'garbage
collection' in order to consolidate the unused volume into one contiguous
span, and then continue with interpretation -- performing the $tring
operation.

To your second question: you've overlooked the "extraordinary" $tring
animals. These creatures begin their life born as ordinary $tring animals
(typically 0-length nuls). They then mutate into "extraordinary" $tring
animals of some finite (often substantial) length. What makes these
creatures "extraordinary" $tring animals is that their related $tring
content is ROM-based (not RAM-based in the the $tring-space). Below is an
example of how an "extraordinary" $tring animal is brought into existance.

E%=32676:E$="":
POKE0+VARPTR(E$),25:POKE1+VARPTR(E$),E%MOD256:POKE2+VARPTR(E$),E%\256

E$ was born as an ordinary $tring animal with a LENgth of 0 (nul). In the
ROM-space, address 32676 is the locale of a 25-cell that holds a bunch of
values that are ASCII character codes.

Note that the $tring variable called E$, like any other type of variable,
lives in the variable-space within RAM. In the case of a $tring variable,
the variable-space holds two attributes: LENgth, and Address_of_content.
The function VARPTR, as applied to a $tring variable, returns the locale of
the LENght attribute. So 0+VARPTR(E$) is the locale for LENgth of the
$tring variable called E$. In the variable-space for a $tring variable, the
LENgth attribute is immediately followed by the Address_of_content
attribute. So 1+VARPTR(E$) and 2+VARPTR(E$), respectively, are the Least
significant and the Most significant halves of the locale for
Address_of_content of the $tring variable called E$. Via three POKEs, the
creature called E$ mutates into an "extraordinary" $tring animal.

Sure, go ahead. Do a PRINT E$ statement in order to discover what the
ROM-based content looks like (you can't resist the temptation).

What makes the "extraordinary" $tring animals so extraordinary in contrast
to ordinary $tring animals? Although both of these creatures live in the
variable-space, as do creatures of all variable types, they obtain their
runs of character codes from radically different media. The ordinary $tring
animal "feeds" from RAM media: within a BASIC statement in the case of
"literal" food, or within the $tring-space in the case of changeable food.
The "extraordinary" $tring animal "feeds" from ROM media where all food is
"literal" in the sense that it's cast in stone (i.e., silicon).

To your third question: you've overlooked whether or not the BASIC
interpreter recognizes the difference between an ordinary $tring animal and
an "extraordinary" $tring animal. Offhand, I don't have a concrete answer.
Whenever I have occasion to create "extraordinary" $tring animals, most of
the time they are of very substantial LENgth yet there is no operational
program activity that would amount to exposure to "garbage collection"
events. However, I dimly recall investigating the question a long time ago.
As I recall, I was delighted and surprised to discover that the BASIC
interpreter does recognize the difference between ordinary $tring animals
and "extraordinary" $tring animals such that the potential for, and management of, "garbage collection" events is not impacted by the existence of
"extraordinary" $tring animals. At least that's what I recall. My
recollection likely is accurate given how the BASIC interpreter already
recognizes those ordinary $tring animals that have "literal" food in a BASIC
statement -- to the BASIC interpreter, those creatures perhaps "look the
same as" any existing "extraordinary" $tring animals with respect to
"garbage collection" considerations.

[[Category:Model T Developer Reference]]

Ronw: Spelling and grammer corrections only.

2009-03-02T15:28:05Z

Spelling and grammer corrections only.

← Older revision		Revision as of 08:28, 2 March 2009
Line 56:		Line 56:
	interpreter recognizes the difference between an ordinary $tring animal and		interpreter recognizes the difference between an ordinary $tring animal and
	an "extraordinary" $tring animal. Offhand, I don't have a concrete answer.		an "extraordinary" $tring animal. Offhand, I don't have a concrete answer.
	Whenever I have ~~occassion~~ to create "extraordinary" $tring animals, most of		Whenever I have occasion to create "extraordinary" $tring animals, most of
	the time they are of very substantial LENgth yet there is no operational		the time they are of very substantial LENgth yet there is no operational
	program activity that would amount to exposure to "garbage collection"		program activity that would amount to exposure to "garbage collection"
	events. However, I dimly recall investigating the question a long time ago.		events. However, I dimly recall investigating the question a long time ago.
	As I recall, I was delighted and surprised to discover that the BASIC		As I recall, I was delighted and surprised to discover that the BASIC
	interpreter does recognize the difference between an ordinary $tring animals		interpreter does recognize the difference between ordinary $tring animals
	and an "extraordinary" $tring animals such that the potential for, and ~~manag~~		and "extraordinary" $tring animals such that the potential for, and management of, "garbage collection" events is not impacted by the existence of
	~~ement~~ of, "garbage collection" events is not impacted by the ~~existance~~ of
	"extraordinary" $tring animals. At least that's what I recall. My		"extraordinary" $tring animals. At least that's what I recall. My
	recollection likely is accurate given how the BASIC interpreter already		recollection likely is accurate given how the BASIC interpreter already

Jhoger at 06:56, 31 January 2009

2009-01-31T06:56:08Z

← Older revision		Revision as of 23:56, 30 January 2009
Line 70:		Line 70:
	same as" any existing "extraordinary" $tring animals with respect to		same as" any existing "extraordinary" $tring animals with respect to
	"garbage collection" considerations.		"garbage collection" considerations.

			[[Category:Model T Developer Reference]]

Jhoger at 07:13, 27 December 2008

2008-12-27T07:13:07Z

← Older revision		Revision as of 00:13, 27 December 2008
Line 22:		Line 22:
	example of how an "extraordinary" $tring animal is brought into existance.		example of how an "extraordinary" $tring animal is brought into existance.

	E%=32676:E$="":		E%=32676:E$="":
	POKE0+VARPTR(E$),25:POKE1+VARPTR(E$),E%MOD256:POKE2+VARPTR(E$),E%\256		POKE0+VARPTR(E$),25:POKE1+VARPTR(E$),E%MOD256:POKE2+VARPTR(E$),E%\256

	E$ was born as an ordinary $tring animal with a LENgth of 0 (nul). In the		E$ was born as an ordinary $tring animal with a LENgth of 0 (nul). In the

Jhoger: New page: Ron Wiesen, in response to a question from Wilson Van Alst: To your first question: the situation of $trings (i.e., where they sit) in the $tring-space can set the stage for a compelled '...

2008-12-27T07:12:41Z

New page: Ron Wiesen, in response to a question from Wilson Van Alst: To your first question: the situation of $trings (i.e., where they sit) in the $tring-space can set the stage for a compelled '...

New page

Ron Wiesen, in response to a question from Wilson Van Alst:

To your first question: the situation of $trings (i.e., where they sit) in
the $tring-space can set the stage for a compelled 'garbage collection' that
takes place, as a neccessary prelude, to a subsequent $tring operation. In
other words, the $tring-space holds existing $trings which are not adjoined
(unused gaps of space are between $trings) and then the BASIC interpreter
encounters some $tring operation. The total volume of unused $tring-space
is sufficient to support the $tring operation. But that total is fragmented
due to the way existing $trings are situated in the $tring-space. This
compels the BASIC interpreter to suspend interpretation, conduct 'garbage
collection' in order to consolidate the unused volume into one contiguous
span, and then continue with interpretation -- performing the $tring
operation.

To your second question: you've overlooked the "extraordinary" $tring
animals. These creatures begin their life born as ordinary $tring animals
(typically 0-length nuls). They then mutate into "extraordinary" $tring
animals of some finite (often substantial) length. What makes these
creatures "extraordinary" $tring animals is that their related $tring
content is ROM-based (not RAM-based in the the $tring-space). Below is an
example of how an "extraordinary" $tring animal is brought into existance.

E%=32676:E$="":
POKE0+VARPTR(E$),25:POKE1+VARPTR(E$),E%MOD256:POKE2+VARPTR(E$),E%\256

E$ was born as an ordinary $tring animal with a LENgth of 0 (nul). In the
ROM-space, address 32676 is the locale of a 25-cell that holds a bunch of
values that are ASCII character codes.

Note that the $tring variable called E$, like any other type of variable,
lives in the variable-space within RAM. In the case of a $tring variable,
the variable-space holds two attributes: LENgth, and Address_of_content.
The function VARPTR, as applied to a $tring variable, returns the locale of
the LENght attribute. So 0+VARPTR(E$) is the locale for LENgth of the
$tring variable called E$. In the variable-space for a $tring variable, the
LENgth attribute is immediately followed by the Address_of_content
attribute. So 1+VARPTR(E$) and 2+VARPTR(E$), respectively, are the Least
significant and the Most significant halves of the locale for
Address_of_content of the $tring variable called E$. Via three POKEs, the
creature called E$ mutates into an "extraordinary" $tring animal.

Sure, go ahead. Do a PRINT E$ statement in order to discover what the
ROM-based content looks like (you can't resist the temptation).

What makes the "extraordinary" $tring animals so extraordinary in contrast
to ordinary $tring animals? Although both of these creatures live in the
variable-space, as do creatures of all variable types, they obtain their
runs of character codes from radically different media. The ordinary $tring
animal "feeds" from RAM media: within a BASIC statement in the case of
"literal" food, or within the $tring-space in the case of changeable food.
The "extraordinary" $tring animal "feeds" from ROM media where all food is
"literal" in the sense that it's cast in stone (i.e., silicon).

To your third question: you've overlooked whether or not the BASIC
interpreter recognizes the difference between an ordinary $tring animal and
an "extraordinary" $tring animal. Offhand, I don't have a concrete answer.
Whenever I have occassion to create "extraordinary" $tring animals, most of
the time they are of very substantial LENgth yet there is no operational
program activity that would amount to exposure to "garbage collection"
events. However, I dimly recall investigating the question a long time ago.
As I recall, I was delighted and surprised to discover that the BASIC
interpreter does recognize the difference between an ordinary $tring animals
and an "extraordinary" $tring animals such that the potential for, and manag
ement of, "garbage collection" events is not impacted by the existance of
"extraordinary" $tring animals. At least that's what I recall. My
recollection likely is accurate given how the BASIC interpreter already
recognizes those ordinary $tring animals that have "literal" food in a BASIC
statement -- to the BASIC interpreter, those creatures perhaps "look the
same as" any existing "extraordinary" $tring animals with respect to
"garbage collection" considerations.