Initial project import

tools/v/vlib/rand/config/config.v

@@ -0,0 +1,49 @@
+// Copyright (c) 2019-2024 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+module config
+
+import rand.seed
+
+// PRNGConfigStruct is a configuration struct for creating a new instance of the default RNG.
+// Note that the RNGs may have a different number of u32s required for seeding. The default
+// generator WyRand used 64 bits, ie. 2 u32s so that is the default. In case your desired generator
+// uses a different number of u32s, use the `seed.time_seed_array()` method with the correct
+// number of u32s.
+@[params]
+pub struct PRNGConfigStruct {
+pub:
+	seed_ []u32 = seed.time_seed_array(2)
+}
+
+// Configuration struct for generating normally distributed floats. The default value for
+// `mu` is 0 and the default value for `sigma` is 1.
+@[params]
+pub struct NormalConfigStruct {
+pub:
+	mu    f64 = 0.0
+	sigma f64 = 1.0
+}
+
+// Configuration struct for the shuffle functions.
+// The start index is inclusive and the end index is exclusive.
+// Set the end to 0 to shuffle until the end of the array.
+@[params]
+pub struct ShuffleConfigStruct {
+pub:
+	start int
+	end   int
+}
+
+// validate_for is a helper function for validating the configuration struct for the given array.
+pub fn (config ShuffleConfigStruct) validate_for[T](a []T) ! {
+	if config.start < 0 || config.start >= a.len {
+		return error("argument 'config.start' must be in range [0, a.len)")
+	}
+	if config.end < 0 || config.end > a.len {
+		return error("argument 'config.end' must be in range [0, a.len]")
+	}
+	if config.end != 0 && config.end <= config.start {
+		return error("argument 'config.end' must be greater than 'config.start'")
+	}
+}