Hello, world!

Makefile

@@ -0,0 +1,2 @@
+run:
+	go run internal/main.go -o hello.zig programs/hello.go

internal/main.go

@@ -0,0 +1,92 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"os"
+	"strings"
+)
+
+var (
+	outputFilepath *string = flag.String("o", "out.zig", "Zig output filename")
+)
+
+func init() {
+	flag.Parse()
+}
+
+func main() {
+	inputFilepaths := flag.Args()
+
+	if len(inputFilepaths) > 1 {
+		panic("Only support one file!")
+	} else if len(inputFilepaths) < 1 {
+		panic("Must supply one input file")
+	}
+
+	inputFilepath := inputFilepaths[0]
+
+	fset := token.NewFileSet()
+
+	f, err := parser.ParseFile(fset, inputFilepath, nil, parser.AllErrors)
+	if err != nil {
+		panic(err)
+	}
+
+	output, err := generate(f)
+	if err != nil {
+		panic(err)
+	}
+	outputFile, err := os.Create(*outputFilepath)
+	if err != nil {
+		panic(err)
+	}
+	_, err = outputFile.WriteString(output)
+	if err != nil {
+		panic(err)
+	}
+	fmt.Printf("%v:\n", *outputFilepath)
+	fmt.Println("--------------------")
+	fmt.Println(output)
+}
+
+func generate(f *ast.File) (string, error) {
+	sb := new(strings.Builder)
+
+	def := f.Decls[0].(*ast.FuncDecl)
+
+	if def.Name.Name != "main" {
+		return "", fmt.Errorf("must have main")
+	}
+
+	sb.WriteString(`const std = @import("std");`)
+	sb.WriteString("\npub fn main() void {\n")
+
+	stmt := def.Body.List[0].(*ast.ExprStmt)
+	call := stmt.X.(*ast.CallExpr)
+	fn := call.Fun.(*ast.Ident)
+
+	if fn.Name == "print" {
+		sb.WriteString(fmt.Sprintf(`std.debug.print(`))
+
+		args := call.Args
+		for _, arg := range args {
+			if s, ok := arg.(*ast.BasicLit); ok {
+				sb.WriteString(fmt.Sprintf("%s", s.Value))
+			} else {
+				panic("WTF")
+			}
+		}
+
+		sb.WriteString(", .{});\n")
+	} else {
+		return "", fmt.Errorf("expected printf")
+	}
+
+	sb.WriteString("}\n")
+
+	return sb.String(), nil
+}

programs/hello.go

@@ -0,0 +1,5 @@
+package main
+
+func main() {
+	print("Hello, world\n")
+}