50 lines
981 B
Forth
50 lines
981 B
Forth
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# enumeration
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This is a method of creating a set of constants from names
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provided in an array.
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The approach was inspired by 8th[1], in which a short modifier
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allows setting the enum value at any time. In use this looks
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like:
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{ 'a 'b=10 'c 'd=998 'e 'f 'g=33 } a:enum
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In this case:
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a is 0
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b is 10
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c is 11
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d is 998
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e is 999
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f is 1000
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g is 33
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Enumerations start at zero by default.
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# Code
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The approach used here is to iterate over strings in an array.
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If the string contains a `=`, split the string, convert the
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part after the `=` to a number, which will replace the enum
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value. It then creates a constant using the string and
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increments the counter.
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~~~
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:a:enum (a-)
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#0 swap
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[ dup $= s:contains-char?
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[ nip $= s:split [ n:inc s:to-number ] dip ] if
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over &const dip n:inc
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] a:for-each drop ;
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~~~
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# Test
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```
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{ 'a=10 'b 'c 'd=998 'e 'f } a:enum
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```
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# References
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[1] https://8th-dev.com/forum/index.php/topic,1979.msg11377.html
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