mach: Implement basic URI parser for resource system

src/resource/uri_parser.zig

@@ -0,0 +1,46 @@
+const std = @import("std");
+const mem = std.mem;
+
+pub const Uri = struct {
+    scheme: []const u8,
+    path: []const u8,
+};
+
+pub const Error = error{InvalidUri};
+
+pub fn parseUri(uri: []const u8) Error!Uri {
+    const scheme_end = mem.indexOfScalar(u8, uri, ':');
+    if (scheme_end == null)
+        return error.InvalidUri;
+
+    const scheme = uri[0..scheme_end.?];
+
+    if (scheme_end.? + 3 >= uri.len)
+        return error.InvalidUri;
+
+    if (uri[scheme_end.? + 1] != '/' or uri[scheme_end.? + 2] != '/')
+        return error.InvalidUri;
+
+    const path = uri[scheme_end.? + 3 ..];
+
+    return Uri{
+        .scheme = scheme,
+        .path = path,
+    };
+}
+
+const testing = std.testing;
+const expectError = testing.expectError;
+const expectEqualStrings = testing.expectEqualStrings;
+
+test "invalid" {
+    try expectError(error.InvalidUri, parseUri("xyz"));
+    try expectError(error.InvalidUri, parseUri("xyz:"));
+    try expectError(error.InvalidUri, parseUri("xyz:/"));
+    try expectError(error.InvalidUri, parseUri("xyz://"));
+}
+
+test "path" {
+    try expectEqualStrings("xyz", (try parseUri("xyz://abc")).scheme);
+    try expectEqualStrings("abc", (try parseUri("xyz://abc")).path);
+}