Life of a Clojure Expression
summary
Follows one map literal from source through the reader, analyzer, bytecode emitter and runtime, showing that a two-key map becomes a persistent array map (<=8 entries) and that constant keys are emitted as static constants, the compiler calls RT.mapUniqueKeys and emits ASM bytecode via ASM so HotSpot can inline the size checks. Relies on Compiler.java (8500+ lines) and shows the compiled class extending AFunction with a single invoke method returning the constructed map.
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chapters (7)
- 0:00Start
- 0:20Disclaimers
- 4:14Lisp Breeder Java
- 4:42Map Reader
- 7:05Eval
- 10:16Macro Expand
- 23:56Static Method Invocation
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