feat: add basic csv loading

src/csv.zig

@@ -0,0 +1,96 @@
+const std = @import("std");
+
+const CsvError = error{
+    NoDelimiterFound,
+};
+
+fn contains(arr: []const u8, target: u8) bool {
+    for (arr) |element| {
+        if (element == target) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+pub fn determineDelimiter(str: []const u8) !u8 {
+    const possibleDelimiter = []u8{ ',', ';', '\t', '|' };
+    var countMap = std.AutoHashMap(u8, u32);
+
+    for (possibleDelimiter) |del| {
+        countMap.put(del, 0);
+    }
+
+    for (str) |c| {
+        if (!contains(possibleDelimiter, c)) {
+            continue;
+        }
+
+        const current = countMap.get(c);
+        countMap.put(c, current + 1);
+    }
+
+    var currDel: u8 = ' ';
+    var highest: u32 = 0;
+
+    for (countMap.keyIterator()) |key| {
+        const val = try countMap.get(key);
+        if (val > highest) {
+            currDel = key;
+            highest = val;
+        }
+    }
+
+    if (currDel == ' ') {
+        return CsvError.NoDelimiterFound;
+    }
+
+    return currDel;
+}
+
+pub fn loadFile(filepath: []const u8) !void {
+    const alloc = std.heap.page_allocator;
+    var file = try std.fs.cwd().openFile(filepath, .{});
+    defer file.close();
+
+    var buf_reader = std.io.bufferedReader(file.reader());
+    var in_stream = buf_reader.reader();
+    var buffer: [4096]u8 = undefined;
+
+    var readHeader = false;
+    var headerList = undefined;
+    var entries = std.ArrayList(std.ArrayList([]const u8)).init(alloc);
+    var delimiter = ' ';
+
+    while (try in_stream.readUntilDelimiterOrEof(&buffer, '\n')) |line| {
+        if (delimiter == ' ') {
+            delimiter = determineDelimiter(line);
+        }
+
+        var entr = std.ArrayList([]const u8).init(alloc);
+        const splitIt = std.mem.split(u8, line, delimiter);
+        for (splitIt) |part| {
+            _ = try entr.append(part);
+        }
+
+        if (!readHeader) {
+            headerList = entr;
+            readHeader = true;
+            continue;
+        }
+        _ = try entries.append(entr);
+    }
+}
+
+test "Determine delimiter" {
+    const del = try determineDelimiter("this,is,a,test");
+    std.testing.expect(del == ',');
+
+    const del2 = try determineDelimiter("th#is; is,a; test;     with,many;symbols");
+    std.testing.expect(del2 == ';');
+
+    determineDelimiter("This does not have an delimiter") catch |err| {
+        try std.testing.expect(err == CsvError.NoDelimiterFound);
+    };
+}

src/main.zig

@@ -1,24 +1,28 @@
 const std = @import("std");
+const csv = @import("csv.zig");
 
 pub fn main() !void {
-    // Prints to stderr (it's a shortcut based on `std.io.getStdErr()`)
-    std.debug.print("All your {s} are belong to us.\n", .{"codebase"});
-
-    // stdout is for the actual output of your application, for example if you
-    // are implementing gzip, then only the compressed bytes should be sent to
-    // stdout, not any debugging messages.
     const stdout_file = std.io.getStdOut().writer();
     var bw = std.io.bufferedWriter(stdout_file);
     const stdout = bw.writer();
+    const alloc = std.heap.page_allocator;
 
-    try stdout.print("Run `zig build test` to run the tests.\n", .{});
+    var args = try std.process.ArgIterator.initWithAllocator(alloc);
+    _ = args.next();
 
-    try bw.flush(); // don't forget to flush!
-}
-
-test "simple test" {
-    var list = std.ArrayList(i32).init(std.testing.allocator);
-    defer list.deinit(); // try commenting this out and see if zig detects the memory leak!
-    try list.append(42);
-    try std.testing.expectEqual(@as(i32, 42), list.pop());
+    var filepath: [:0]const u8 = "";
+
+    if (args.next()) |value| {
+        filepath = value;
+    }
+
+    if (std.mem.eql(u8, filepath, "")) {
+        _ = try stdout.write("No file specified");
+        _ = try bw.flush();
+        return;
+    }
+
+    try csv.loadFile(filepath);
+
+    _ = try bw.flush();
 }

src/root.zig

@@ -1,10 +1,7 @@
 const std = @import("std");
+const csv = @import("csv.zig");
 const testing = std.testing;
 
-export fn add(a: i32, b: i32) i32 {
-    return a + b;
-}
-
-test "basic add functionality" {
-    try testing.expect(add(3, 7) == 10);
+test {
+    testing.refAllDecls(@This());
 }