Add joker.io/read function.

#504

std/io.joke

@@ -24,3 +24,10 @@
   {:added "1.0"
    :go "close(f)"}
   [^Object f])
+
+(defn ^String read
+  "Reads up to n bytes from IOReader r and returns a string of the read bytes.
+  May return a shorter (or blank) string if EOF is encountered."
+  {:added "1.3.6"
+   :go "read(r, n)"}
+  ^String [^IOReader r ^Int n])

std/io/a_io.go

@@ -60,6 +60,24 @@ func __pipe_(_args []Object) Object {
 	return NIL
 }
 
+var __read__P ProcFn = __read_
+var read_ Proc = Proc{Fn: __read__P, Name: "read_", Package: "std/io"}
+
+func __read_(_args []Object) Object {
+	_c := len(_args)
+	switch {
+	case _c == 2:
+		r := ExtractIOReader(_args, 0)
+		n := ExtractInt(_args, 1)
+		_res := read(r, n)
+		return MakeString(_res)
+
+	default:
+		PanicArity(_c)
+	}
+	return NIL
+}
+
 func Init() {
 
 	InternsOrThunks()

std/io/a_io_slow_init.go

@@ -34,4 +34,10 @@ func InternsOrThunks() {
   with code expecting an IOWriter.
   Returns a vector [reader, writer].`, "1.0"))
 
+	ioNamespace.InternVar("read", read_,
+		MakeMeta(
+			NewListFrom(NewVectorFrom(MakeSymbol("r"), MakeSymbol("n"))),
+			`Reads up to n bytes from IOReader r and returns a string of the read bytes.
+  May return a shorter (or blank) string if EOF is encountered.`, "1.3.6").Plus(MakeKeyword("tag"), String{S: "String"}))
+
 }

std/io/io_native.go

@@ -22,3 +22,12 @@ func close(f Object) Nil {
 	}
 	panic(RT.NewError("Object is not closable: " + f.ToString(false)))
 }
+
+func read(r io.Reader, n int) string {
+	buf := make([]byte, n)
+	cnt, err := r.Read(buf)
+	if err != io.EOF {
+		PanicOnErr(err)
+	}
+	return string(buf[:cnt])
+}