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slides/main.md

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+---
+theme: dracula
+paginate: true
+_paginate: false
+footer: Topics in Compilers and Concurrency · Julius Fischer · 10.06.2026
+_footer: ""
+style: |
+  h1 {
+    position: absolute;
+    top: 60px;
+    left: 75px;
+    right: 75px;
+  }
+---
+
+# Destination Calculus:
+## A Linear 𝜆-Calculus for Purely Functional Memory Writes
+### Topics in Compiler and Concurrency
+#### Julius Fischer
+
+###### 10. Juni 2026
+
+---
+# What are Destinations?
+- Destination Passing Style
+    - Imperative
+    - Function takes destination instead of returning structure
+---
+# Example in C
+```
+int* vec_add(int v1[], int v2[], int size) {
+    int* res =  malloc(size * sizeof(int));
+    for (int i = 0; i < size; i++) {
+        res[i] = v1[i] + v2[i];
+    }
+    return res;
+}
+```
+- Add an 'out parameter'
+```
+void dps_vec_add(int res[], int v1[], int v2[], int size) {
+    for (int i = 0; i < size; i++) {
+        res[i] = v1[i] + v2[i];
+    }
+}
+```
+---
+# Motivation for DPS
+- Typical functional map implementation
+```
+map f (x:xs) = (f x : map f xs1)
+> (f x : map f xs) 
+> (map f x1 : (f x2 : map f xs2)) 
+> ...
+```
+- Not tail recursive 
+    - Performance issue
+    - Inefficient stack growth
+```
+map f (x:xs) dest = map f xs (push dest (f x))
+> map f xs1 (push dest (f x1))
+> map f xs2 (push dest (f x2))
+```
+--- 
+# DPS in functional languages
+- Just add pointers to mutable data?
+    - $Int \mapsto Int \mapsto Int \mapsto \textcolor{red}{T}$
+    - $\textcolor{red}{T *}\mapsto Int \mapsto Int \mapsto Int \mapsto Void$
+
+---
+# Destination Calculus
+- It's 
+
+--- 
+# Referenes

slides/makefile

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 clean:
 	rm -rf ./out
 compile: 
-	marp src.md --theme ./themes/academic.css -o out/presentation.html
+	marp main.md --theme ./themes/academic.css -o out/presentation.html

slides/src.md

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----
-theme: dracula
-paginate: true
-_paginate: false
-footer: Mini-Haskell · Julius Fischer · 19.11.2024
-_footer: ""
----
-
-# Destination Calculus:
-## A Linear 𝜆-Calculus for Purely Functional Memory Writes
-### Technische Fakultät Freiburg
-#### Julius Fischer
-
-###### 10. Juni 2026
-
----
-
-# Referenes

slides/src/dps.c

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+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+void pretty_print(uint size, int v[]) {
+    printf("[");
+    for  (int i = 0; i < size; i++)
+        printf("%d,", v[i]);
+    printf("]\n");
+}
+
+int* vec_add(int v1[], int v2[], int size) {
+    int* res =  malloc(size * sizeof(int));
+    for (int i = 0; i < size; i++) {
+        res[i] = v1[i] + v2[i];
+    }
+    return res;
+}
+
+void dps_vec_add(int res[], int v1[], int v2[], int size) {
+    for (int i = 0; i < size; i++) {
+        res[i] = v1[i] + v2[i];
+    }
+}
+
+#define SIZE 5
+int main(int argc, char** argv) {
+    int v1[SIZE] = {1, 2, 4, 5, 10};
+    int v2[SIZE] = {2, 2, 1, 2, 1};
+    int *added = vec_add(v1, v2, SIZE);
+    pretty_print(SIZE, added);
+
+    int dest[SIZE] = {2, 2, 1, 2, 1};
+    dps_vec_add(dest, v1, v2, SIZE);
+    pretty_print(SIZE, dest);
+    return 0;
+}
+