I'm doing different language each day, all solutions here.

Today's Go (dunno why I used named returns instead of just returning the score in part1/2()..):

package main

import (
    "bufio"
    "fmt"
    "log"
    "os"
)

func main() {
    file, err := os.Open("input.txt")
    if err != nil {
        log.Fatal(err)
    }

    var score1, score2 int

    scanner := bufio.NewScanner(file)
    for scanner.Scan() {
        score1 += part1(scanner.Text())
        score2 += part2(scanner.Text())
    }

    if err := scanner.Err(); err != nil {
        log.Fatal(err)
    }

    fmt.Println(score1)
    fmt.Println(score2)
}

func part1(round string) (score int) {
    switch round {
    case "A X":
        score += 4
    case "A Y":
        score += 8
    case "A Z":
        score += 3
    case "B X":
        score += 1
    case "B Y":
        score += 5
    case "B Z":
        score += 9
    case "C X":
        score += 7
    case "C Y":
        score += 2
    case "C Z":
        score += 6
    }
    return
}

func part2(round string) (score int) {
    switch round {
    case "A X":
        score += 3
    case "A Y":
        score += 4
    case "A Z":
        score += 8
    case "B X":
        score += 1
    case "B Y":
        score += 5
    case "B Z":
        score += 9
    case "C X":
        score += 2
    case "C Y":
        score += 6
    case "C Z":
        score += 7
    }
    return
}