84 lines
1,023 B
Go
84 lines
1,023 B
Go
package main
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import (
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"bufio"
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"fmt"
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"log"
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"os"
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)
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func main() {
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switch len(os.Args) {
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case 1:
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runPrompt()
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case 2:
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runFile(os.Args[1])
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default:
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println("Usage: glox [file]")
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os.Exit(1)
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}
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}
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func runPrompt() {
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scanner := bufio.NewScanner(os.Stdin)
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scanner.Split(bufio.ScanLines)
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for {
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print("> ")
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scanner.Scan()
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line := scanner.Text()
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if len(line) == 0 {
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break
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}
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run([]byte(scanner.Text()))
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hadError = false
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hadRuntimeError = false
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}
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}
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func runFile(path string) {
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file, err := os.ReadFile(path)
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try(err)
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run(file)
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switch {
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case hadError:
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os.Exit(65)
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case hadRuntimeError:
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os.Exit(70)
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default:
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os.Exit(0)
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}
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}
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func run(source []byte) {
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tokens := newScanner(source).scan()
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if hadError {
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return
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}
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ast := newParser(tokens).parse()
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if hadError {
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return
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}
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println(AstStringer{}.String(ast))
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res := newInterpreter().evaluate(ast)
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if hadRuntimeError {
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return
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}
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fmt.Printf("%v\n", res)
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}
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func try(err error) {
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if err != nil {
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log.Fatal(err)
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}
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}
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