Merge api.go into main.go

It would be really painful to provide variables there

api.go

@@ -1,36 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"net/http"
-)
-
-func writeError(w http.ResponseWriter, status int, err interface{}) {
-	w.WriteHeader(status)
-	w.Write([]byte(fmt.Sprintln(err)))
-}
-
-func ApiHandler(w http.ResponseWriter, req *http.Request) {
-	from := req.FormValue("from")
-	if from == "" {
-		writeError(w, 400, "'from' field is missing")
-		return
-	}
-	to := req.FormValue("to")
-	if to == "" {
-		writeError(w, 400, "'to' field is missing")
-		return
-	}
-	text := req.FormValue("text")
-	if text == "" {
-		writeError(w, 400, "'text' field is missing")
-		return
-	}
-
-	translation, err := Translate(from, to, text)
-	if err != nil {
-		writeError(w, 500, err)
-	}
-
-	w.Write([]byte(translation))
-}

main.go

@@ -17,6 +17,7 @@
 package main
 
 import (
+	"fmt"
 	"html/template"
 	"log"
 	"net/http"
@@ -60,7 +61,31 @@ func main() {
 
 		tmpl.ExecuteTemplate(w, "index", indexPageData{from, to, text, translation})
 	}).Methods("GET", "POST")
-	r.HandleFunc("/api", ApiHandler).Methods("POST")
+
+	r.HandleFunc("/api", func(w http.ResponseWriter, req *http.Request) {
+		from := req.FormValue("from")
+		if from == "" {
+			writeError(w, 400, "'from' field is missing")
+			return
+		}
+		to := req.FormValue("to")
+		if to == "" {
+			writeError(w, 400, "'to' field is missing")
+			return
+		}
+		text := req.FormValue("text")
+		if text == "" {
+			writeError(w, 400, "'text' field is missing")
+			return
+		}
+
+		translation, err := Translate(from, to, text)
+		if err != nil {
+			writeError(w, 500, err)
+		}
+
+		w.Write([]byte(translation))
+	}).Methods("POST")
 
 	// Static files
 	fs := http.FileServer(http.Dir(*staticDir))
@@ -69,3 +94,8 @@ func main() {
 	log.Println("Starting on", *bind)
 	log.Fatalln(http.ListenAndServe(*bind, r))
 }
+
+func writeError(w http.ResponseWriter, status int, err interface{}) {
+	w.WriteHeader(status)
+	w.Write([]byte(fmt.Sprintln(err)))
+}