Add a port to Go

cmd/interpreter/main.go

@@ -0,0 +1,63 @@
+//
+// Copyright (c) 2018, Přemysl Janouch <p@janouch.name>
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+//
+
+// Program interpreter is a basic ell interpreter.
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+
+	"janouch.name/ell/ell"
+)
+
+func main() {
+	var script []byte
+	var err error
+
+	if len(os.Args) < 2 {
+		script, err = ioutil.ReadAll(os.Stdin)
+	} else {
+		script, err = ioutil.ReadFile(os.Args[1])
+	}
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+
+	L := ell.New()
+	if !ell.StdInitialize(L) {
+		fmt.Printf("runtime library initialization failed: %s\n", L.Error)
+	}
+
+	program, err := ell.NewParser(script).Run()
+	if err != nil {
+		fmt.Printf("%s: %s\n", "parse error", err)
+		os.Exit(1)
+	}
+
+	var args *ell.V
+	tail := &args
+	for i := 2; i < len(os.Args); i++ {
+		*tail = ell.NewString([]byte(os.Args[i]))
+		tail = &(*tail).Next
+	}
+
+	var result *ell.V
+	if !L.EvalBlock(program, args, &result) {
+		fmt.Printf("%s: %s\n", "runtime error", L.Error)
+	}
+}