56 lines
1 KiB
Forth
56 lines
1 KiB
Forth
# UTF-8 Characters
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UTF-8 allows for characters to be one to four bytes long. Since Retro
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is 32-bits internally, all characters can fit into a sincle entry on
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the stack. These words will be used to pack and unpack the character
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values.
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~~~
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:uc:pack (????n-c) ;
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:uc:unpack (c-????n) ;
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~~~
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# UTF-8 Strings
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Strings in Retro have been C-style null terminated sequences of ASCII
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characters. I'm seeking to change this as I'd like to support Unicode
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(UTF-8) and to merge much of the string and array handling code.
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This will be an ongoing process.
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Temporary sigil.
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~~~
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:sigil:" (-a) a:from-string class:data ; immediate
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~~~
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Return the length (in utf8 characters or bytes) of a string.
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~~~
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:us:length (a-n) #0 swap [ #192 and #128 -eq? + ] a:for-each n:abs ;
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:us:length/bytes (a-n) a:length ;
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~~~
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~~~
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~~~
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Fetch a character from a string.
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~~~
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:us:fetch (an-c) ;
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~~~
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Store a character into a string.
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~~~
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:us:store (can-) ;
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~~~
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Tests.
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```
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"((V⍳V)=⍳⍴V)/V←,V us:length n:put nl
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"((V⍳V)=⍳⍴V)/V←,V us:length/bytes n:put nl
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```
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