refactor: move regexp compile to top, reduce redundant logic (#1)

main.go

@@ -6,8 +6,8 @@ import (
 	"log"
 	"os"
 	"regexp"
-	"strings"
 	"strconv"
+	"strings"
 )
 
 type Span struct {
@@ -50,11 +50,16 @@ type Config struct {
 	depthLimit int
 }
 
+var rVerboseFlag = regexp.MustCompile("^-(?P<verbosity>(v{1,2}))$")
+var rDepthPattern = regexp.MustCompile("--depth=(?P<depth>([1-9][0-9]*|0))")
+
 // Prints traces recursively with increasing ident levels.
 // More data is printed until there are no more traces available
 // i.e. until the ChildrenIds key yields an empty array.
 func recursivelyPrintTraces(idToSpanMap map[string]Span, current string, config Config, depth int) {
-    if depth > config.depthLimit { return }
+	if depth > config.depthLimit {
+		return
+	}
 
 	currentSpan := idToSpanMap[current]
 	prefix := strings.Repeat(" ", depth)
@@ -68,7 +73,9 @@ func recursivelyPrintTraces(idToSpanMap map[string]Span, current string, config
 	if config.verbosity > 1 {
 		meta, err := json.MarshalIndent(currentSpan.Meta, "", "  ")
 
-        if err != nil { panic(err) }
+		if err != nil {
+			panic(err)
+		}
 
 		log.Println(fmt.Sprintf("%s %s", prefix, meta))
 	}
@@ -123,30 +130,24 @@ func parseTraceJsonFromFile(path string) TraceData {
 	return fullTrace
 }
 
+// Parses command-line arguments to extract flags and
+// other useful contextual details.
 func parseArgs(args []string) Config {
-    collectedArgs := map[string]bool{}
+	rootOfInterest := os.Args[2]
+	tracePath := os.Args[1]
+	verbosity := 0
+	depth := 9999
 
 	for _, arg := range os.Args {
-        collectedArgs[arg] = true
+		verbosity_match := rVerboseFlag.FindAllString(arg, -1)
+
+		if verbosity_match != nil {
+			verbosity = len(verbosity_match[0])
+			continue
 		}
 
-    verbosity := 0
-
-    _, verbose := collectedArgs["-v"]
-
-    if verbose { verbosity = 1 }
-
-    _, veryVerbose := collectedArgs["-vv"]
-
-    if veryVerbose { verbosity = 2 }
-
-    depthPattern := "--depth=(?P<depth>([1-9][0-9]*|0))"
-    rDepthPattern := regexp.MustCompile(depthPattern)
-
 		depthMatch := rDepthPattern.FindStringSubmatch(strings.Join(os.Args, " "))
 
-    depth := 9999
-
 		if depthMatch != nil {
 			depthValueIndex := rDepthPattern.SubexpIndex("depth")
 
@@ -159,10 +160,9 @@ func parseArgs(args []string) Config {
 			}
 
 			depth = depthLimit
+			continue
+		}
 	}
-
-    rootOfInterest := os.Args[2]
-    tracePath := os.Args[1]
 
 	return Config{rootOfInterest, tracePath, verbosity, depth}
 }