initial commit

src/main.zig

@@ -0,0 +1,70 @@
+const std = @import("std");
+const zlog = @import("zlog");
+
+const Options = enum {
+    a,
+    b,
+    c,
+};
+
+const Struct = struct {
+    a: usize = 42,
+    b: bool = true,
+    c: [5]u16 = .{ 1, 2, 3, 4, 5 },
+    d: []const u8 = "string",
+    e: Options = Options.b,
+
+    // pub fn format(value: Struct, comptime fmt: []const u8, options: std.fmt.FormatOptions, writer: anytype) !void {
+    //     // TODO: make the creation of this function comptime
+    //     try writer.writeAll("main.Struct{ ");
+    //     try writer.writeAll(".a: usize = ");
+    //     try std.fmt.formatIntValue(value.a, fmt, options, writer);
+    //     try writer.writeAll(", ");
+
+    //     try writer.writeAll(".b: bool = ");
+    //     try std.fmt.formatBuf(if (value.b) "true" else "false", options, writer);
+    //     try writer.writeAll(", ");
+
+    //     try writer.writeAll(".c: [5]u16 = ");
+    //     try std.fmt.format(writer, "{any}", .{value.c});
+    //     try writer.writeAll(", ");
+
+    //     try writer.writeAll(".d: []const u8 = ");
+    //     try std.fmt.format(writer, "\"{s}\"", .{value.d});
+    //     try writer.writeAll(", ");
+
+    //     try writer.writeAll(".e: main.Options = ");
+    //     try std.fmt.format(writer, "{any}", .{value.e});
+
+    //     try writer.writeAll(" }");
+    // }
+
+    // TODO: can this become comptime entirely? - i.e. create the entire struct through a helper function and provide the created one with the format function already attached?
+    pub fn format(value: Struct, comptime fmt: []const u8, options: std.fmt.FormatOptions, writer: anytype) anyerror!void {
+        try zlog.generic_format(value, fmt, options, writer);
+    }
+};
+
+pub const std_options = zlog.std_options;
+
+pub fn main() void {
+    // initialize zlog with the scope of `main`
+    const log = std.log.scoped(.main);
+    // NOTE: the scope of `default` will result in no scoping being printed in
+    // the resulting output
+
+    // some variables to log
+    const int_var = 42;
+    const array_var = [_]i32{ 1, 2, 3, 4 };
+    const string_var = "This is a test";
+    const option_var = Options.a;
+    const struct_var: Struct = .{};
+
+    // NOTE: Depending on the optimization target some of these log messages
+    // will not show, which is inline with the behavior of `std.log`.
+    log.debug("Debug message {any}", .{int_var});
+    log.info("Info message {any}", .{array_var});
+    log.info("Info message \"{s}\"", .{string_var});
+    log.warn("Warning message {any}", .{option_var});
+    log.err("Error message {any}", .{struct_var});
+}

src/zlog.zig

@@ -0,0 +1,88 @@
+const std = @import("std");
+
+const max_depth = 5;
+
+// pub fn format(value: ?, comptime fmt: []const u8, options: std.fmt.FormatOptions, writer: anytype) !void
+// TODO: provide comptime helper function to add format function for user types:
+// - pretty printing
+// - compact printing
+// - show types of struct members
+// Maybe the corresponding configurations for the `format` function could also
+// be effected by build time configurations
+
+pub const std_options: std.Options = .{
+    .logFn = logFn,
+};
+
+// zlog defaultLog function replacement, which adjusts the surrounding contents of every std.log message.
+fn logFn(
+    comptime message_level: std.log.Level,
+    comptime scope: @Type(.EnumLiteral),
+    comptime format: []const u8,
+    args: anytype,
+) void {
+    // TODO: provide build time configuration to allow tweaking corresponding output
+    // - add timestamp to all log messages
+    // - change output file for writing messages to (default `stderr`)
+
+    // TODO: improve formatting output, such that the resulting log has a good feel
+    // - should there be indenting?
+    // - should there be spacing?
+    // - should the messages be aligned (left, center, right)?
+    const level_txt = comptime message_level.asText();
+    const prefix2 = if (scope == .default) ":\t" else "(" ++ @tagName(scope) ++ "):\t";
+    const stderr = std.io.getStdErr().writer();
+    var bw = std.io.bufferedWriter(stderr);
+    const writer = bw.writer();
+
+    std.debug.lockStdErr();
+    defer std.debug.unlockStdErr();
+    nosuspend {
+        writer.print(level_txt ++ prefix2 ++ format ++ "\n", args) catch return;
+        bw.flush() catch return;
+    }
+}
+
+pub fn generic_format(object: anytype, comptime fmt: []const u8, options: std.fmt.FormatOptions, writer: anytype) !void {
+    _ = fmt;
+    _ = options;
+    const Object = @TypeOf(object);
+    const object_info = @typeInfo(Object);
+    switch (object_info) {
+        .Struct => |s| {
+            try writer.writeAll(@typeName(Object));
+            try writer.writeAll(" = {\n");
+            inline for (s.fields) |field| {
+                try writer.writeAll("\t .");
+                try writer.writeAll(field.name);
+                try writer.writeAll(" = ");
+                // TODO check corresponding type and try to adapt fmt accordingly!
+                try std.fmt.format(writer, "{any}", .{@field(object, field.name)});
+                try writer.writeAll(",\n");
+            }
+            try writer.writeAll("}");
+        },
+        else => {},
+    }
+}
+
+pub fn enhance_format(comptime object: type) type {
+    // TODO: append a function to the type if it is a user defined type
+
+    // NOTE: this has the clear disadvantage that the type is not the same anymore! (but maybe this is still fine)
+    const object_info = @typeInfo(object);
+    switch (object_info) {
+        .Struct => |s| {
+            return @Type(.{
+                .Struct = .{
+                    .layout = .auto,
+                    .fields = s.fields,
+                    .decls = s.decls,
+                    .is_tuple = false,
+                },
+            });
+        },
+        else => {},
+    }
+    return object;
+}