ell/cmd/interpreter/main.go

64 lines
1.5 KiB
Go

//
// 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)
}
}