github.com/dickermoshe/zmanim-core/zmanim_core

Zmanim Core - Go Bindings

Go bindings for the Zmanim Core library, providing Jewish calendar calculations and zmanim (halachic times) functionality.

Prerequisites

• Go 1.16 or later
• CGO enabled (default)

Installation

Option 1: Dynamic Linking (Recommended)

• Install the Go package:

  go get github.com/dickermoshe/zmanim-core/zmanim_core
  

• Download the dynamic libraries from the GitHub releases page

• Place the library files in your Go project directory:

  • Windows: Copy zmanim_core.dll to the same directory as your Go executable
  • Linux: Copy libzmanim_core.so to your system library path (e.g., /usr/local/lib/) or the same directory as your executable
  • macOS: Copy libzmanim_core.dylib to your system library path or the same directory as your executable

• Import and use the Go bindings:

package main

import (
	"fmt"
	"time"

	zmanim_core "github.com/dickermoshe/zmanim-core/zmanim_core"
)

func main() {
	msSinceEpoch := time.Now().UnixMilli()
	location := zmanim_core.NewGeolocation(31.768319, 35.213711, 0)
	calendar := zmanim_core.NewAstronomicalCalendar(msSinceEpoch, *location)
	sunrise := calendar.GetSunrise()
	// Parse the sunrise time to a time.Time ms since epoch
	sunriseTime := time.UnixMilli(*sunrise)
	fmt.Println("Sunrise time:", sunriseTime)
}

• Build and run:

go build -o your_app main.go
./your_app  # On Windows: your_app.exe

Option 2: Static Linking

If you prefer to statically link the Rust library into your Go binary:

• Download the static libraries from the GitHub releases page

  • Windows: zmanim_core.lib
  • Linux/macOS: libzmanim_core.a

• Place the static library in your project directory or system library path

• Build with static linking flags:

# Windows
set CGO_ENABLED=1
set CGO_LDFLAGS=-L. -lzmanim_core
go build -ldflags "-linkmode external -extldflags -static" -o your_app.exe main.go

# Linux/macOS
export CGO_ENABLED=1
export CGO_LDFLAGS="-L. -lzmanim_core"
go build -ldflags "-linkmode external -extldflags -static" -o your_app main.go

Troubleshooting

Common Issues

• "cannot find library" error:

  • Ensure the dynamic library is in the same directory as your executable
  • On Linux/macOS, you can also add the library path to LD_LIBRARY_PATH

• CGO compilation errors:

  • Make sure CGO is enabled: export CGO_ENABLED=1 (Linux/macOS) or set CGO_ENABLED=1 (Windows)
  • Verify that you have a C compiler installed (gcc, clang, or MSVC)

• Static linking issues:

  • Ensure you have the static library file (.lib, .a) not the dynamic one
  • Some systems may require additional system libraries to be linked

License

This project is licensed under the same license as the main Zmanim Core project.