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| title |
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| 3. Grammar and Parser |
3.1. Define a token type
{% include_code simple_language_plugin/src/com/simpleplugin/psi/SimpleTokenType.java %}
3.2. Define an element type
{% include_code simple_language_plugin/src/com/simpleplugin/psi/SimpleElementType.java %}
3.3. Define grammar
Define a grammar for the properties language with /com/simpleplugin/Simple.bnf file.
{% include_code simple_language_plugin/src/com/simpleplugin/Simple.bnf lang:java %}
As you see a properties file can contain properties, comments and line breaks.
The grammar defines how flexible the support for a language can be. We specified that a property may have or may not have key and value. This lets the IDE still recognise incorrectly defined properties and provide corresponding code analysis and quick-fixes.
3.4. Generate a parser
Now when the grammar is defined we can generate a parser with PSI classes via Generate Parser Code from the context menu or via ⌘⇧G shortcut on Simple.bnf file. The Grammar-Kit will generate a parser and PSI elements in gen folder. Mark this folder as a source root and make sure everything is compiled without errors.
