···

       
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*/

     

       
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```

     

       
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+
       
Furthermore, interpolations don't have to just be RegHex matchers. They can

     

       
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also be functions returning matchers or completely custom matching functions.

     

       
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This is useful when your DSL becomes _self-referential_, i.e. when one matchers

     

       
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start referencing each other forming a loop. To fix this we can create a

     

       
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function that returns our root matcher:

     

       
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+
       


     

       
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```js

     

       
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+
       
import match from 'reghex';

     

       
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+
       


     

       
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+
       
const value = match('value')`

     

       
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+
       
  (${/\w+/} | ${() => root})+

     

       
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+
       
`;

     

       
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+
       


     

       
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+
       
const root = match('root')`

     

       
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+
       
  ${/root/}+ ${value}

     

       
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`;

     

       
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+
       
```

     

       
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+
       


     

       
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### Regex-like DSL

     

       
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We've seen in the previous examples that matchers are authored using tagged