Dan's Reverse Polish Language
Running
npm run example will run an example
npm test will run tests
./drpl FILE or npm run drpl FILE will interpret FILE.
Aims
Aims to have as few commands as possible with macros to extend. Stack based.
Considerations: A read only stack or a preinitialised stack. Maybe needs return codes.
Commands
stdlib
w write: Pops fd, string. Pushes nothing.
c copy: Pops any, Pushes two any.
+ add: Pops two numbers, pushes one.
- sub: Pops two numbers, pushes one.
* mul: Pops two numbers, pushes one.
/ div: Pops two numbers, pushes one (dies horribly if #2 is 0).
s swap: Pops two any, pushes in reverse order.
Accepts quotes " ` or '
colours
col: pops type, colour, pushes string.
types:
fg: foreground
bg: background
set: setting
colours:
black
red
green
yellow
blue
magenta
cyan
white
settings:
rst: reset
brt: bright
dim: dim
usc: underscore
bln: blink
rev: reverse
hdn: hidden
Example:
"This should be red." red fg col + 1 w
"This should not." rst set col + 1 w
Future
Commands
r read: Pops fd, string. Pushes nothing.
b blocking-read: Pops fd, string. Pushes nothing.
f func: May define a function or macro somehow later.
j jump: may not be needed since we want it more functional
l loop: may or may not be a macro depending on
If labels and gotos are necessary, probably it'll be:
labelname:
0 @labelname jne (jump if not equal)
Example
Loops?
100 c 1 w l: BOBOTW 1 w c 1 w BOB 1 w TODAPIA 1 w - c 1 w 1 @l jne
Macros
p print: 1 w
i input: 0 b
l loop: something like je e 0 - e; which would require asm's je
but we might not do jumping hmm...
Syntax highlighting extensions
??? Researching.
Disclaimer
I may have just reinvented Forth. But it's fun.