forth.clj

references

notes

;; memory layout {1 {:kind :word :code-word (fn []) ;; intrinsic :word "WORD1" :prev 123} 2 {:kind :word :code-word nil;; ["WORD1" "WORD9"] ;; DOCOL word :word "WORD2"} 3 {:kind :val :val 123}}

;; execute ;; bootstrap at 0 ;; run ENTER ;; pushes ip+1 to return stack ;; execute current word ;; if word -> check code-word if intrinsic -> execute ;; if val -> fault

;; NEXT ;; loads IP into a reg (eax) ;; increments IP ;; jmp to (eax) ;; needed on all native and in DOCOL

;; EXIT pops, set IP and calls NEXT ;; DOCOL runs functions not compile them

{0 {:kind :word :code-word (fn []) ;; intrinsic :word "ENTER" :prev nil} 1 {:kind :word :code-word (fn []) ;; intrinsic :word "EXIT" :prev 0} 2 {:kind :word :code-word (fn []) ;; intrinsic :word "DOCOL" :prev nil} 3 {:kind :word :code-word (fn []) ;; intrinsic :word "PUSH" :prev 0} 4 {:kind :word :code-word (fn []) ;; intrinsic :word "NATIVEFOO" :prev nil} 5 {:kind :word :code-word (fn []) ;; intrinsic :word "NATIVEBAR" :prev 0} 454 {:kind :word :code-word nil ;; : COMPILEDFOO NATIVEFOO NATIVEBAR ; :word "COMPILEDFOO" :prev 333} ;; do we need explict ENTER or is this the code-word 455 {:kind :word :code-word 4} 456 {:kind :word :code-word 5} 457 {:kind :word :code-word 1} ;; this is EXIT 458 {:kind :word :code-word nil ;; : COMPILEDBAR NATIVEBAR 123 NATIVEFOO COMPILEDFOO ; :word "COMPILEDBAR" :prev 454} ;; ??? 459 {:kind :word :code-word 1} 460 {:kind :val :val 123} 461 {:kind :word :code-word 0} 462 {:kind :word :code-word 454} 463 {:kind :word :code-word 1} ;; this is EXIT }

;; COMPILEDFOO ;; search from LATEST (457) via :prev ;; check :word for match ;; set IP to 457 ;; ENTER moves from here ;; move to 457 + 1 ;; ENTER (458) -> push 459 onto return stack ;; jump to :code-word (1) ;; check :code-word ;; native? -> call native fn ;; EXIT pop rs and jump to 459 ;; ENTER (459) -> push 460 onto return stack ;; ENTER (460) -> push 461 onto return stack

ppmclala/forth.clj

forth.clj

references

notes