Package org.drools.compiler.lang
Interface Expander
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- All Known Implementing Classes:
DefaultExpander
public interface Expander
Expanders are extension points for expanding expressions in DRL at parse time. This is just-in-time translation, or macro expansion, or whatever you want. The important thing is that it happens at the last possible moment, so any errors in expansion are included in the parsers errors. Just-in-time expansions may include complex pre-compilers, or just macros, and everything in between. Expanders should ideally not make presumptions on any embedded semantic language. For instance, java aware pre processing should be done in drools-java semantic module, not in the parser itself. Expanders should be reusable across semantic languages.
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description void
addDSLMapping(DSLMapping mapping)
Add the new mapping to this expander.String
expand(Reader drl)
Expands (process) the expression Just-In-Time for the parser.String
expand(String source)
Expands (process) the expression Just-In-Time for the parser.List<ExpanderException>
getErrors()
Returns the list of errors from the last expansion madeboolean
hasErrors()
Returns true in case the last expansion had any errors
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Method Detail
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expand
String expand(Reader drl) throws IOException
Expands (process) the expression Just-In-Time for the parser. If the source is not meant to be expanded, or if no appropriate match was found for expansion, it will echo back the same expression.- Parameters:
drl
- the source code to be pre-processed- Returns:
- source code after running pre-processors
- Throws:
IOException
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expand
String expand(String source)
Expands (process) the expression Just-In-Time for the parser. If the source is not meant to be expanded, or if no appropriate match was found for expansion, it will echo back the same expression.- Parameters:
source
- the source code to be expanded- Returns:
- source code after running pre-processors
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addDSLMapping
void addDSLMapping(DSLMapping mapping)
Add the new mapping to this expander.- Parameters:
mapping
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getErrors
List<ExpanderException> getErrors()
Returns the list of errors from the last expansion made- Returns:
- A list of
ExpanderException
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hasErrors
boolean hasErrors()
Returns true in case the last expansion had any errors- Returns:
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