46 lines
1.4 KiB
ReStructuredText
46 lines
1.4 KiB
ReStructuredText
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Write You a Forth, 0x05
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-----------------------
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:date: 2018-02-24 12:23
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:tags: wyaf, forth
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Today I need to start actually doing things with tokens. This requires two
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things:
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1. Some idea of what a word is, and
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2. A dictionary of words
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I started taking some notes on this previously, and I think there are a few
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kinds of words that are possible:
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1. Numbers (e.g. defining a variable)
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2. Built-in functions
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3. Lambda functions (that is, user-defined functions).
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Stage 1 really only needs to incorporate #2, so that's what I'll focus on for
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now. However, to prepare for the future, I'm going to define a ``Word`` base
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class and inherit from there. This interface is going to need to be
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stack-aware, so what I've done is define a ``System`` struct in ``system.h``::
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#ifndef __KF_CORE_H__
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#define __KF_CORE_H__
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#include "defs.h"
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#include "stack.h"
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typedef struct _System {
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Stack<KF_INT> dstack;
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} System;
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#endif // __KF_CORE_H__
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This will let me later add in support for the return stack and other things
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that might be useful. Other ideas: adding something like an ``errno``
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equivalent to indicate the last error, and storing a dictionary of words. This
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will need some restructuring, though. Anyways, this works for now.
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The Word interface
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^^^^^^^^^^^^^^^^^^
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Now I can start defining a Word.h.
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