lsparrish

Block Conversion

Author:	Charles Childers
Version:	2009.12.21

Blocker User's Guide

lsparrish

Chorded Key Entry

Author:	Luke Parrish
Version:	2009.12.22

Chorder User Guide

Overview

lsparrish

( This is an implementation of crc's ifExists which demonstrates the )
( parsing of curly braces for the conditional evaluation of text.    )

{{
  : cut ( a-a )
    dup getLength over + 1- dup @ 32 =if
      0 swap ! else drop then ;
  : "cut ( c"-a ) accept tib tempString cut ;
  : '{ ( "-a ) char: { "cut ;
  : '} ( "-a ) char: } "cut ;

lsparrish

( ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ )
( For loop with an index that counts from zero, placed on the )
( top of the stack with each iteration. Uses NORS to keep     )
( track of the original value, so nexti must be used to clean )
( up when loop is complete.                                   )
( ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ )
: fori ` dup ` push ` for ` pop ` pop ` 2dup 
       ` push ` push ` swap ` - ; compile-only
: nexti ` next ` pop ` drop ; compile-only

lsparrish

( This is an attempt at creating some rather sophisticated macros )
( using fori/nexti. It does not work yet. )

{{
  variable addr

  : pad       ( -    ) addr @ @ 6 for dup base @ r pow <if 32 emit then next ;

  : .wrap     ( -   ) ." ( " later ."  )" ;
  : .name     ( a-  ) .wrap d->name type ;

lsparrish

( Stack and list manipulation. )

: allot heap +! ;
: -allot heap -! ;

: sav ` dup ` push ; immediate

: tempsave ( ?n- ) for here r 1- + ! next ;
: tempload ( n-? ) for here r 1- + @ next ;

lsparrish

( A macro for appending code blocks. )
{{
: prepend ( $$-$ ) here -rot 2 for dup here swap getLength dup allot copy next 0 , ;
: $space ( $-$ ) s"  " prepend ;
---reveal---
: append-block 32 accept tib @ char: { =if 
    char: } accept tib tempString keepString literal,
    ` $space ` swap ` prepend then ; compile-only
: code ( "- ) ` append-block ` dup ` getLength ` eval ; compile-only
}}

lsparrish

: | char: | accept ;
{{
  | find   $-   ::: true if $ is a word. |
  | accept c"-  ::: parsed text (delimited by c) goes at tib |
  | tib     -$  ::: used to access text after parsing. |
  | nip   xy-y  ::: shorthand for swap drop |
  | dup    n-nn ::: duplicate top of stack |
  | char:  "-c  ::: macro, gets a char at compile time. |
  | if     f-   ::: jump to then if flag is false (at execute time) |
  | then    -   ::: macro for the place that if jumps to when flag is false. |

lsparrish

( ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ )
( do ... until                                                )
( ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ )
( Value n is taken from the stack and stored to a virtual     )
( variable. When this number is equal to the TOS at the time  )
( until is executed, the loop terminates.                     )
( ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ )

{{
: skipped-nop ( - ) 8 , here 2 + ,  0 , ;

lsparrish

The program:

( buffering input )

{{
64 constant width
4  constant lines
variable num