PLT Redex: a semantics engineers toolkit Robby Findler & Casey - PowerPoint PPT Presentation

PLT Redex: a semantics engineer’s toolkit Robby Findler & Casey Klein University of Chicago 1

Critical Infrastructure 2

Heavy-duty Tools 3

Simpler Jobs 4

Mismatched Tools 5

The Right Tool for the Job 6

Sometimes, Overhead Matters 7

Isabelle, HOL, Coq, Twelf, ... PLT Redex 8

PLT Redex EDSL Tools define-language traces, stepper reduction-relation typesetting define-metafunction test suites 9

PLT Redex EDSL Tools define-language traces, stepper reduction-relation typesetting define-metafunction test suites 10

Target, i (define-language lang (e (e e ...) x v) (v number ( � (x ...) e) + *) (x (variable-except � + *)) (E hole (v ... E e ...))) 11

Target, ii (define red (reduction-relation lang (--> (in-hole E (+ number ...)) (in-hole E ,(apply + (term (number ...)))) +) (--> (in-hole E (* number ...)) (in-hole E ,(apply * (term (number ...)))) *) (--> (in-hole E (( � (x ...) e) v ...)) (in-hole E (subst-n ((x v) ... e))) � v))) 12

Executable (traces lang red (term ((( � (x) (x x)) ( � (x) (x x))) (* (+ 1 2) (+ 3 4))))) 13

For fun (define-language lang2 (e (e e ...) x v) (v number ( � (x ...) e) + *) (x (variable-except � + *)) (E hole (e ... E e ...))) 14

For fun (traces lang2 red2 (term ((( � (x) (x x)) ( � (x) (x x))) (* (+ 1 2) (+ 3 4))))) 15

http://www.cs.uchicago.edu/~robby/plt-redex/ 16