From 11641596fa34073e8c137dd4019793ebc2d31424 Mon Sep 17 00:00:00 2001
From: Aadhavan Srinivasan <aadhavan@twomorecents.org>
Date: Sun, 17 Nov 2024 21:49:11 -0500
Subject: [PATCH] Read multiple lines from stdin and apply regex to each one;
Convert the array of matchIndex structs into a flat array of indices; speeds
up process of checking if we have to print a character in color
---
main.go | 50 ++++++++++++++++++++++++++++----------------------
1 file changed, 28 insertions(+), 22 deletions(-)
diff --git a/main.go b/main.go
index d92d56f..816b8f1 100644
--- a/main.go
+++ b/main.go
@@ -383,33 +383,39 @@ func main() {
var re string
re = os.Args[1]
var test_str string
- // Read test string from stdin
+ var err error
+ // Create reader for stdin and writer for stdout
reader := bufio.NewReader(os.Stdin)
- test_str, err := reader.ReadString('\n')
- if err != nil && err != io.EOF {
- panic(err)
- }
- //fmt.Scanln(&test_str)
+ out := bufio.NewWriter(os.Stdout)
+
re_postfix := shuntingYard(re)
startState := thompson(re_postfix)
- matchIndices := findAllMatches(startState, test_str)
-
- inColor := false
- if len(matchIndices) > 0 {
- for i, c := range test_str {
- for _, indices := range matchIndices {
- if i >= indices.startIdx && i < indices.endIdx {
- color.New(color.FgRed).Printf("%c", c)
- inColor = true
- break
+ // Read every string from stdin until we encounter an error. If the error isn't EOF, panic.'
+ for test_str, err = reader.ReadString('\n'); err == nil; test_str, err = reader.ReadString('\n') {
+ matchIndices := findAllMatches(startState, test_str)
+ // Decompose the array of matchIndex structs into a flat unique array of ints - if matchIndex is {4,7}, flat array will contain 4,5,6
+ // This should make checking O(1) instead of O(n)
+ indicesToPrint := new_uniq_arr[int]()
+ for _, idx := range matchIndices {
+ indicesToPrint.add(genRange(idx.startIdx, idx.endIdx)...)
+ }
+ if len(matchIndices) > 0 {
+ for i, c := range test_str {
+ if indicesToPrint.contains(i) {
+ color.New(color.FgRed).Fprintf(out, "%c", c)
+ } else {
+ fmt.Fprintf(out, "%c", c)
}
}
- if inColor == false {
- fmt.Printf("%c", c)
- }
- inColor = false
+ } else {
+ fmt.Fprint(out, test_str)
+ }
+ err = out.Flush()
+ if err != nil {
+ panic(err)
}
- } else {
- fmt.Print(test_str)
+ }
+ if err != io.EOF {
+ panic(err)
}
}