From cce2320974e214e81ebf2564c4e17f1c9912ae88 Mon Sep 17 00:00:00 2001
From: Daniel Bulant <danbulant@gmail.com>
Date: Mon, 2 Dec 2024 20:12:11 +0100
Subject: [PATCH] start working on c

---
 .vscode/settings.json |   6 ++
 2024/c/.gitignore     |   1 +
 2024/c/01.c           | 124 ++++++++++++++++++++++++++++++++++++++++++
 2024/c/Makefile       |  14 +++++
 4 files changed, 145 insertions(+)
 create mode 100644 .vscode/settings.json
 create mode 100644 2024/c/.gitignore
 create mode 100644 2024/c/01.c
 create mode 100644 2024/c/Makefile

diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 0000000..2ac52f0
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,6 @@
+{
+    "files.associations": {
+        "*.nomad": "hcl",
+        "vector": "c"
+    }
+}
\ No newline at end of file
diff --git a/2024/c/.gitignore b/2024/c/.gitignore
new file mode 100644
index 0000000..c5e82d7
--- /dev/null
+++ b/2024/c/.gitignore
@@ -0,0 +1 @@
+bin
\ No newline at end of file
diff --git a/2024/c/01.c b/2024/c/01.c
new file mode 100644
index 0000000..7561aae
--- /dev/null
+++ b/2024/c/01.c
@@ -0,0 +1,124 @@
+#include <stdlib.h> 
+#include <stdio.h>
+#include <string.h>
+
+#define usize unsigned long
+
+// A Vector type
+struct DynSlice {
+    void* data;
+    usize size;
+    usize capacity;
+    usize size_of;
+};
+
+// Constructs a new dyn slice, a vector type
+// default capacity is 0 and no backing data is allocated, use DS_grow
+struct DynSlice DS_create(usize size_of) {
+    struct DynSlice slice;
+    slice.data = NULL;
+    slice.size = 0;
+    slice.capacity = 0;
+    slice.size_of = size_of;
+    return slice;
+}
+
+// Exit with message and error code 1
+void panic(char* msg) {
+    printf("%s\n", msg);
+    exit(1);
+}
+
+// Grows slice to at least the given size (nearest power of 2 higher)
+// panics if malloc fails
+void DS_grow(struct DynSlice* slice, usize newcap) {
+    usize cap = slice->capacity;
+    usize size = slice->size;
+    printf("Growing %li %li\n", cap, size);
+
+    void* dataptr = slice->data;
+    
+    if(cap == 0) cap = 1;
+    while(cap < newcap) {
+        cap <<= 1;
+    }
+
+    void* newdataptr = malloc(cap * slice->size_of);
+    if(newdataptr == NULL) {
+        panic("DS malloc failed during grow");
+    }
+    if(dataptr) {
+        memcpy(newdataptr, dataptr, size * slice->size_of);
+        free(dataptr);
+    }
+    slice->capacity = cap;
+    slice->data = newdataptr;
+}
+
+void DS_debugprint(struct DynSlice* slice) {
+    printf("dynslice, size %li, cap %li, size of %li", slice->size, slice->capacity, slice->size_of);
+}
+
+// Pushes a new object. Accepts a pointer to said object. Copies. 
+// returns index of pushed data
+// assumes size_of from slice. Take care of types lol.
+usize DS_push(struct DynSlice* slice, void* ptr) {
+    usize cap = slice->capacity;
+    usize size = slice->size;
+    if(cap <= size) {
+        DS_grow(slice, cap+1);
+    }
+    memcpy(slice->data + slice->size * slice->size_of, ptr, slice->size_of);
+    slice->size += 1;
+    return size;
+}
+
+// Extends a slice from another array-like object
+void DS_extend(struct DynSlice* slice, void* ptr, usize count) {
+    if(slice->capacity < slice->size + count) DS_grow(slice, slice->size + count);
+    printf("extending %li\n", count);
+    DS_debugprint(slice);
+    memcpy(slice->data + slice->size * slice->size_of, ptr, slice->size_of * count);
+    slice->size += count;
+}
+
+// Extends DynSlice from another DynSlice, checking their sizes for (partial) memory safety
+void DS_extend_slice(struct DynSlice* target, struct DynSlice* src) {
+    if(target->size_of != src->size_of) {
+        panic("DS invalid extend_slice, different sizes");
+    }
+    DS_extend(target, src->data, src->size);
+}
+
+// Extends a slice from string. Checks size_of is correct, and calls strlen
+void DS_extend_string(struct DynSlice* slice, void* ptr) {
+    if(slice->size_of != sizeof(char)) panic("DS extend string on a non-char slice");
+    usize len = strlen(ptr);
+    DS_extend(slice, ptr, len);
+}
+
+// Drops slice in place - resets to empty
+void DS_drop(struct DynSlice* slice) {
+    slice->capacity = 0;
+    slice->size = 0;
+    free(slice->data);
+}
+
+// Gets pointer to a single element, checking it's size
+void* DS_get(struct DynSlice* slice, usize i) {
+    if(slice->size >= i) {
+        panic("DS Get out of bounds");
+    }
+    return slice->data + i * slice->size_of;
+}
+
+int main() {
+    // FILE* file = fopen("input.txt", "r");
+    setvbuf(stdout, NULL, _IONBF, 0);
+    struct DynSlice example = DS_create(sizeof(char));
+    DS_extend_string(&example, "Hello, ");
+    DS_extend_string(&example, "world!");
+    DS_push(&example, '\0');
+    printf("%s\n", (char*)example.data);
+    DS_drop(&example);
+}
\ No newline at end of file
diff --git a/2024/c/Makefile b/2024/c/Makefile
new file mode 100644
index 0000000..b1b7360
--- /dev/null
+++ b/2024/c/Makefile
@@ -0,0 +1,14 @@
+CC = gcc
+CFLAGS = -g
+
+all: 01
+
+createdir:
+	mkdir -p bin
+
+01: createdir 01.c
+	gcc 01.c -o bin/01
+	./bin/01
+
+clean:
+	rm -r bin
\ No newline at end of file