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// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package main
import (
"fmt"
"log"
"os"
)
func main() {
if len(os.Args) < 2 {
name := os.Args[0]
fmt.Printf("Usage: %v \"EXPRESSION\"\n", name)
fmt.Printf("Example: %v \"( 1 - -3 ) / 3 + 2 * ( 3 + -4 ) + 3 %% 2^2\"\n =2\n", name)
os.Exit(1)
}
expression := os.Args[1]
calc := &Calculator{Buffer: expression}
calc.Init()
calc.Expression.Init(expression)
if err := calc.Parse(); err != nil {
log.Fatal(err)
}
calc.Execute()
fmt.Printf("= %v\n", calc.Evaluate())
}
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