Code Annotation Module

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type: module title: Code Annotation Module created: 2026-05-25 updated: 2026-05-25 tags:

• domain/annotation status: mature related:
• "Annotation Syntax"
• "Feature Location Module"
• "Annotation Processing Flow" sources:
• .raw/CodeAnnotationInjector.java

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Code Annotation Module

Package: se.isselab.HAnS.featureAnnotation.codeAnnotation

CodeAnnotationInjector

Implements MultiHostInjector. Registered in plugin.xml as a multiHostInjector.

What it targets

elementsToInjectIn() returns [PsiComment.class]. The injector is called for every PSI comment in every file.

Early exits:

• Skips PsiDocCommentBase (Javadoc).
• Skips comments whose text does not match .*(&begin|&line|&end).*.

Injection logic

1. Retrieve Commenter for the host language via LanguageCommenters.INSTANCE.forLanguage(). Falls back to // / /* / */ if no commenter is registered.
2. Calls registrar.startInjecting(CodeAnnotationLanguage.INSTANCE).
3. Determines TextRange to inject based on token type:

Token type	TextRange injected
END_OF_LINE_COMMENT	[lineCommentPrefix.length, textLength) — strips leading //
C_STYLE_COMMENT	[blockCommentPrefix.length, textLength - blockCommentSuffix.length) — strips /* and */
Other	[0, textLength) — full text

4. Calls registrar.doneInjecting().

[!key-insight] The injector strips comment delimiters so the injected CodeAnnotations language fragment sees only the annotation text (e.g. &begin[Feature]), not // &begin[Feature].

PSI types produced by CodeAnnotations grammar

These types are defined in the generated PSI for the CodeAnnotations language:

PSI class	Role
CodeAnnotationBeginmarker	Represents &begin[...] marker
CodeAnnotationEndmarker	Represents &end[...] marker
CodeAnnotationLinemarker	Represents &line[...] marker
CodeAnnotationFeature	Feature name within a marker
CodeAnnotationLpq	Fully-qualified LPQ feature reference
CodeAnnotationParameter	Parameter inside brackets

FeatureLocationManager.getMarkerType() uses Java 16+ switch pattern matching on these types:

case CodeAnnotationBeginmarker ignored -> MarkerType.BEGIN
case CodeAnnotationEndmarker   ignored -> MarkerType.END
case CodeAnnotationLinemarker  ignored -> MarkerType.LINE
case null, default             -> MarkerType.NONE

Injection host resolution

When FeatureLocationManager processes a CodeAnnotationFile reference, it checks whether the element's injection host is a PsiComment. This handles both:

• Regular Java/Kotlin files where the annotation is directly in a comment.
• XML/other files where the CodeAnnotations fragment is injected into a host comment (e.g. an XML <!-- &begin[Feature] -->).

Related

• Annotation Syntax — user-facing syntax for &begin/&end/&line
• Feature Location Module — FeatureLocationManager consumes the PSI types produced here
• Annotation Processing Flow — end-to-end flow from comment to metrics