ksp migration

Kotlin/ksp-migration.md

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+# Migrating to KSP
+
+## How kapt and ksp differ?
+
+### Incremental processing
+When writing content to a file during processing with ksp, it is necessary to define output mode.
+
+**Aggregating** means that almost any change in the codebase will consider the input as dirty, (meaning, that the processor needs to run again).
+**Isolating** means that only changes to the specified files will make input dirty.
+
+### Multiple rounds
+ksp executes multiple rounds of processing to make sure all symbols it visits are validated. It’s a useful mechanism if our annotation processing depends on other annotation processors.
+
+PR that migrated WordPress-Android internal processor from kapt to ksp: https://github.com/wordpress-mobile/WordPress-Android/pull/20217