60 lines
1.2 KiB
Markdown
60 lines
1.2 KiB
Markdown
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# Prosper
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Prosper is a Forth-like stack-based language. While taking specific influence from Forth, it does not attempt to emulate or implement the ANS Forth standards.
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Currently, the language is entirely interactive -- to explore, simply run `go run .` in the root of this project and an interactive session will begin.
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## Syntax
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Prosper is stack-based, as mentioned, so all the standard stack semantics are present:
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```
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> 1 2 3 4 + * -
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ok
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> .
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-13 ok
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```
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New words can be defined using `: ;`:
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```
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> : SQUARE DUP * ;
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ok
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> 10 SQUARE .
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100 ok
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```
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It has a single loop construct, `DO LOOP`:
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```
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> : TOFIVE 5 0 DO I . LOOP ;
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ok
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> TOFIVE
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0 1 2 3 4 ok
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```
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Branches using `IF ELSE THEN` work:
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```
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> : EMOJI 0 < IF 128201 EMIT ELSE 128200 EMIT THEN ;
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ok
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> 100 EMOJI
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📈 ok
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> -100 EMOJI
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📉 ok
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```
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And, of course, it knows how to quit:
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```
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> BYE
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bye
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```
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## Future Plans
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* Implement `VARIABLE` and `CONSTANT` and the various `? ! @` related words
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* Implement `SEE`
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* Implement loading libraries of pre-written functions both from the command-line and at run-time
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* Add much better readline behaviors in the interactive console (up-arrow for history, cursor movement...)
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