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strip trailing whitespace

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Peter Fidelman 2022-05-22 10:52:35 -07:00
parent 541eddad68
commit 8dee9a9bbc
2 changed files with 17 additions and 17 deletions
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4
frustration.4th
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@ -46,7 +46,7 @@ Let's lay out a tail-recursive word in memory like this:
[ Link field ]
[ Name field ]
[ --- Start of code field --- ]
[ Subroutine call to duplicate the return address ] <--- A
[ Subroutine call to duplicate the return address ] <--- A
[ Subroutine call to drop the return address ] <--- B
... Your code goes here ...
@ -158,7 +158,7 @@ LINE 5 --> : ( loop[ key 41 = ? ret ]loop ; immediate
: :noname ( -- xt ) here @ [ ' ] , ] ; immediate
:noname drop rdrop ;
:noname drop rdrop ;
: stars ( n -- ) loop[ dup 0= ? [ , ] 1 - 42 emit ]loop ;
( How does the above code work?

30
frustration.rs
View file

@ -324,7 +324,7 @@ impl Core {
* 102 -> ??? Add the top two values on the data stack.
* ...
* 200 -> ??? Push the value 3 onto the data stack
* 202 -> ??? Push the value 4 onto the data stack
* 202 -> ??? Push the value 4 onto the data stack
* 204 -> ??? Return to caller
*
* Don't worry about the other instructions I am using here. I will
@ -332,7 +332,7 @@ impl Core {
*
* I mostly want to point out the three instructions that I put
* at address 200 because they are a subroutine,
* a small self contained piece of code (6 bytes) that
* a small self contained piece of code (6 bytes) that
* performs a specific task.
*
* Do you think it's cool that you can count exactly how many bytes it
@ -723,7 +723,7 @@ const PRIMITIVES: [Primitive; 16] = [
* Number Instruction Meaning
* ------ ----------- -------
* 7 Literal(3) Push the value 3 onto the data stack
* 9 Literal(4) Push the value 4 onto the data stack
* 9 Literal(4) Push the value 4 onto the data stack
* 65504 RET Return to caller
*
* A linked list is not a very fast data structure but this doesn't really
@ -881,7 +881,7 @@ fn build_dictionary(c: &mut Core) {
* Instruction Number Meaning
* ----------- ------ -------
* Literal(3) 7 Push the value 3 onto the data stack
* Literal(4) 9 Push the value 4 onto the data stack
* Literal(4) 9 Push the value 4 onto the data stack
* RET 65504 Return to caller
*
* Here is a Forth subroutine consisting of a few subroutine calls strung
@ -1121,7 +1121,7 @@ fn build_dictionary(c: &mut Core) {
* ret
* is_zero: move r0, 65535
* ret
*
*
* It wants to emit a jump to is_zero, but that symbol has not been seen
* yet and is unrecognized. On top of that, the assembler also doesn't yet
* know what address is_zero will have, so doesn't know what jump target to
@ -1135,7 +1135,7 @@ fn build_dictionary(c: &mut Core) {
* constraints, find a way to write 0= within the constraints.
*
* Here is a start at solving the problem
*
*
* is_nonzero ( -- 0 )
* Literal(0)
* RET
@ -1167,7 +1167,7 @@ fn build_dictionary(c: &mut Core) {
* DRP <-- Discard it
* Literal(0) <-- Put 0 on the data stack
* RET <-- Return
*
*
* Because we popped off and discarded one item from the return stack, the
* final RET instruction will not return to 0= any more. Instead it will
* skip one level and return to whoever called 0=. This has the result of
@ -1179,7 +1179,7 @@ fn build_dictionary(c: &mut Core) {
* Literal(0)
* INV <-- f=65535 is now pushed to stack
* RET <-- Return
*
*
* I call this pattern "return-from-caller". It is used occasionally in
* real Forth systems. My dialect of Forth will use it extensively to work
* around my CPU's lack of conditional jump.
@ -1426,7 +1426,7 @@ fn build_dictionary(c: &mut Core) {
* optimization, by manually using the "return-from-caller" trick, RTO DRP,
* to "get rid of" the x that is pushed on by the skipws CALL.
*
* skipws ( -- c ) RTO DRP ... Q RET ... skipws
* skipws ( -- c ) RTO DRP ... Q RET ... skipws
*
* 1st loop: return stack: ( caller ) data stack: ( )
* 2nd loop: return stack: ( ) data stack: ( )
@ -1508,7 +1508,7 @@ fn build_dictionary(c: &mut Core) {
RET);
/* "over" is a good building block for further stack shuffling words. */
// 2dup ( a b -- a b a b )
d.entry(); d.name(4, *b"2du"); let twodup = d.here;
forth!(over, over, RET);
@ -1537,7 +1537,7 @@ fn build_dictionary(c: &mut Core) {
* of instructions also starts at an even numbered address.
* You might need to include an extra byte of data as "padding".
*
* In this case we set aside one byte for length and five bytes for
* In this case we set aside one byte for length and five bytes for
* characters, which is a total of six bytes, so no padding is needed.
*/
@ -1936,7 +1936,7 @@ fn build_dictionary(c: &mut Core) {
* Our numbers will be base-10. To build up a base-10 number digit by
* digit, we'll need to be able to multiply by 10. Our CPU has no multiply
* but it does have bit shift, which can be used to multiply or divide an
* unsigned value by any power of two.
* unsigned value by any power of two.
*/
// x10 ( n -- n*10 )
@ -2069,7 +2069,7 @@ fn build_dictionary(c: &mut Core) {
* Forth names this "quit", for the reason that calling "quit" in
* the middle of a compiled program is a reasonable way to bring
* you back to top-level.
*
*
* "quit" is called the "outer interpreter" because it is the outermost
* interpreter loop that Forth uses. Some Forth implementations also
* use an "inner interpreter" to execute their threaded code. Our Forth
@ -2230,7 +2230,7 @@ fn main() {
* This is an important, and dangerous, diversion. For it's
* easy to lose sight of the problem amidst the beauty of the
* solution."
*
*
* -- Chuck Moore, "Programming a Problem-Oriented Language", 1970
*/
@ -2255,7 +2255,7 @@ fn main() {
* There is a shell script supplied that will do all of the above for you.
*
* bash build.sh
*
*
* Please read frustration.4th if you want to learn more about how to
* use Forth.
*/