complex

A complex-number composite for Composition-Oriented Programming. A Complex models Ruby's Complex (a + bi) over a Go complex128 value and exposes its arithmetic as fallible operations that return a Result — so failures (the canonical example being a division by 0+0i) are values, never panics and never nil.

quotient := numerator.Div(denominator)
if quotient.HasError() {
    fmt.Println(quotient.Error().Message()) // "division by zero"
} else {
    fmt.Println(quotient.Payload().(Complex.Interface).ToGoString())
}

Complex follows the org's Null-Object / never-nil invariant (enforced by the nonnil CI analyzer): the NullComplex variant in src/null satisfies the same Interface and reports IsNull() == true.

The package is named Complex (capitalised) because the lowercase complex is a Go builtin function and cannot be used as a package name.

Install

export GOPRIVATE=github.com/go-composites GOPROXY=direct GOSUMDB=off
go get github.com/go-composites/complex@main

Usage

[!NOTE] main.go

package main

import (
    "fmt"

    Complex "github.com/go-composites/complex/src"
)

func main() {
    a := Complex.New(1, 2) // 1+2i
    b := Complex.New(3, 4) // 3+4i

    // Arithmetic returns a Result.
    product := a.Mul(b)
    fmt.Println(product.Payload().(Complex.Interface).ToGoString()) // -5+10i

    // Division by 0+0i is a value, not a NaN/Inf or a panic.
    div := a.Div(Complex.New(0, 0))
    fmt.Println("has error:", div.HasError())  // true
    fmt.Println(div.Error().Message())         // division by zero

    fmt.Println(b.Abs())                        // 5
    fmt.Println(b.Conjugate().ToGoString())     // 3-4i
}

$ task build

API

Constructors

• New(real, imag float64) Interface — build a + bi from its parts.
• FromReal(r float64) Interface — a Complex with a zero imaginary part.
• null.New() Interface — the NullComplex Null-Object (IsNull() == true).

Accessors

• Real() float64, Imaginary() float64.
• ToGoString() string — "a+bi" / "a-bi".
• IsNull() bool.

Arithmetic (each returns Result.Interface)

• Add(other) Result / Sub(other) Result / Mul(other) Result.
• Div(other) Result — a Result carrying Error.New("division by zero") when other is 0+0i.

Magnitude, conjugate and equality

• Abs() float64 — the magnitude (modulus) via math/cmplx.
• Conjugate() Interface — a - bi.
• Equal(other) bool.

License

BSD-3-Clause — see LICENSE.