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include [2021/04/01 13:00] – revuskyinclude [2023/03/03 16:16] – revusky
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 # The INCLUDE Statement # The INCLUDE Statement
  
-JavaCC 21's **INCLUDE** statement allows you to break up your grammar file into multiple physical files. It would look like this typically:+Congo's **INCLUDE** statement allows you to break up your grammar file into multiple physical files. It would look like this typically:
  
     INCLUDE "IncludedGrammar.javacc"     INCLUDE "IncludedGrammar.javacc"
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 In legacy JavaCC, if you defined a token production without specifying a lexical state, any lexical definitions belonged to a lexical state called "DEFAULT". Now, obviously, this is a problem once you have an INCLUDE disposition, because the including and included grammar are liable to have a "DEFAULT" lexical state and, typically, we don't want the respective definitions to clobber one another.  In legacy JavaCC, if you defined a token production without specifying a lexical state, any lexical definitions belonged to a lexical state called "DEFAULT". Now, obviously, this is a problem once you have an INCLUDE disposition, because the including and included grammar are liable to have a "DEFAULT" lexical state and, typically, we don't want the respective definitions to clobber one another. 
  
-Thus, JavaCC 21 introduces a setting called **DEFAULT_LEXICAL_STATE**. That means that any lexical specifications where the lexical state is unspecified are in that state. Thus, a JSON grammar would likely have something like this at the top:+Thus, CongoCC has a setting called **DEFAULT_LEXICAL_STATE**. That means that any lexical specifications where the lexical state is unspecified are in that state. Thus, a JSON grammar would likely have something like this at the top:
  
  
-    DEFAULT_LEXICAL_STATE="JSON";+    DEFAULT_LEXICAL_STATE=JSON;
  
          
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 ## Wrinkles with Code Injection ## Wrinkles with Code Injection
  
-JavaCC still supports the legacy JavaCC constructs of **PARSER_BEGIN...PARSER_END** and **TOKEN_MGR_DECLS**. (For how much longer, I am not making any promises...). However, those constructs are ignored within an **INCLUDE**d grammar. +You can  *inject* code into the generated parser or lexer class, from within an included grammar, but you need to write something like:
- +
-You can still *inject* code into the generated parser or lexer class, from within an included grammar, but you need to write something like:+
  
     INJECT PARSER_CLASS :      INJECT PARSER_CLASS :