Scanner working for single character tokens.

golox/internal/runner/runner.go

@@ -0,0 +1,37 @@
+package runner
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+)
+
+func RunPrompt() {
+	s := bufio.NewScanner(os.Stdin)
+	fmt.Print("> ")
+	for s.Scan() {
+		line := s.Text()
+		Run(line)
+		// TODO: resed hadError wherever it is set.
+		fmt.Print("> ")
+	}
+}
+
+func RunFile(path string) error {
+	fBytes, err := os.ReadFile(path)
+	if err != nil {
+		return fmt.Errorf("could not read script file: %w", err)
+	}
+	Run(string(fBytes))
+	// TODO: check hadError and exit with a 65 code if so.
+	return nil
+}
+
+func Run(source string) {
+	s := NewScanner(source)
+	tokens := s.ScanTokens()
+
+	for _, t := range tokens {
+		fmt.Println(t)
+	}
+}