[ezkimo]

Summary

Every function node previously triggered a linear scan over all registered XPath function classes, calling supports() each time. This change resolves each function name at most once per compiler instance and caches both successful matches and misses.

Changes

• src/Schematron/Compiler/XPathAstCompiler.php
  • Add instance memo map $resolvedFunctions (array<string, XPathFunctionInterface|null>)
  • Add resolveFunction(string $name) to perform and cache resolution
  • Update compileFunction() to use the resolver
  • Update compilePathStepFunction() to use the resolver
  • Cache null as a sentinal for names without a handler

Compatibility

• Compiled PHP output remains unchanged for existing tests
• Function resolution order is unchanged
• Misses are cached, avoiding repeated full scans

Testing

• Existing PHUnit suite passes (49 tests)
• Recommended additional test:
  • Repeated compilation of the same function name resolves once
  • Unknown function names are cached as misses
  • Compiled output remains identical