basic generation

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

Makefile

@@ -0,0 +1,12 @@
+
+run: farts
+	./farts
+
+farts: $(wildcard *.go) farts.go
+	go build -o $@ .
+
+farts.go:
+	go generate
+
+clean:
+	rm -rf *~ farts.go farts

g.go

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+//go:generate go run gen.go -o farts.go
+
+package main
+
+// this file is _just_ here to snag the `go generate` command. Logic is in gen.go

gen.go

@@ -0,0 +1,30 @@
+// +build ignore
+
+package main
+
+import (
+	"flag"
+	"io/ioutil"
+	"log"
+	"os"
+)
+
+var flOutput = flag.String("o", "", "output file to write")
+
+func main() {
+	flag.Parse()
+	err := ioutil.WriteFile(*flOutput, []byte(source), os.FileMode(0644))
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+var source = `
+package main
+
+import "fmt"
+
+func foo() {
+	fmt.Println("brrnnt")
+}
+`

run.go

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+package main
+
+func main() {
+	foo()
+}