25 lines
701 B
Forth
25 lines
701 B
Forth
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This implements a sort of "safety net", adding some compile and runtime
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error checking and reporting.
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The first of these is to extend the `@` and `!` prefixes to check for
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the existence of a word name. In a basic image, if the name isn't found,
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it will resolve to address 0 silently. This will have it report an error
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if the word is not found.
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~~~
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:err:var-not-defined
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'\nERROR:_variable_%s_not_defined\n s:format s:put bye ;
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:if:not-defined (sq-s)
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over d:lookup n:zero? swap if ;
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:prefix:@
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[ err:var-not-defined ] if:not-defined
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d:lookup d:xt fetch class:data |fetch ; immediate
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:prefix:!
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[ err:var-not-defined ] if:not-defined
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d:lookup d:xt fetch class:data |store ; immediate
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~~~
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