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-rw-r--r--entries/fhackett/fib.kk83
-rw-r--r--people.json11
2 files changed, 94 insertions, 0 deletions
diff --git a/entries/fhackett/fib.kk b/entries/fhackett/fib.kk
new file mode 100644
index 0000000..e4d8107
--- /dev/null
+++ b/entries/fhackett/fib.kk
@@ -0,0 +1,83 @@
+
+effect store<k,v> {
+ fun put(key: k, value: v): ()
+ fun get(key: k): maybe<v>
+}
+
+fun no-store(body: () -> <store<k,v>,div|e> t): <div|e> t {
+ with handler {
+ fun get(key) Nothing
+ fun put(key, value) {}
+ } in {
+ body()
+ }
+}
+
+fun list-store(eq: (k,k) -> total bool, body: () -> <store<k,v>,div|e> t): <div|e> t {
+ var data := Nil
+ with handler {
+ fun get(key) {
+ data.lookup fn(candidate-key) key.eq(candidate-key)
+ }
+ fun put(key, value) {
+ data := Cons((key, value), data.filter(fn((kk, _)) !kk.eq(key)))
+ }
+ } in {
+ body()
+ }
+}
+
+fun pair-store(body: () -> <store<int,int>,div|e> t): <console,div|e> t {
+ var first := 0
+ var second := 1
+ var idx := 1
+
+ with handler {
+ fun get(key) {
+ if idx == key then Just(second)
+ else if idx - 1 == key then Just(first)
+ else Nothing
+ }
+ fun put(key, value) {
+ if key == idx + 1 then {
+ idx := idx + 1
+ first := second
+ second := value
+ } else {
+ println("error: " ++ key.show ++ " := " ++ value.show ++ "; " ++ first.show ++ ", " ++ second.show ++ ", " ++ idx.show)
+ }
+ }
+ } in {
+ mask<console>(body)
+ }
+}
+
+fun fib(n: int): <div,store<int,int>> int {
+ match get(n) {
+ Just(result) -> result
+ Nothing ->
+ match n {
+ 0 -> 0
+ 1 -> 1
+ _ ->
+ val result = fib(n - 2) + fib(n - 1)
+ put(n, result)
+ result
+ }
+ }
+}
+
+pub fun fib-naive(n: int): div int {
+ with no-store
+ fib(n)
+}
+
+pub fun fib-list(n: int): div int {
+ with list-store(fn(a: int, b: int) a == b)
+ fib(n)
+}
+
+pub fun fib-pair(n: int): <div,console> int {
+ with pair-store
+ fib(n)
+}
diff --git a/people.json b/people.json
index 4561b11..42d580b 100644
--- a/people.json
+++ b/people.json
@@ -94,6 +94,17 @@
]
},
{
+ "github": "fhackett",
+ "name": "Finn Hackett",
+ "title": "PhD Student, UBC",
+ "entries": [
+ {
+ "name": "koka-store",
+ "link": "./entries/fhackett/fib.kk"
+ }
+ ]
+ },
+ {
"github": "funemy",
"name": "Yanze Li",
"title": "PhD Student, UBC",