Include multiple patterns in regex word break - regex

Question

I have the following program which uses regex to search for a pattern and replaces it a key word.
Sample as shown below will replace names like "Incorp","Inc.","Inc corp" with "Inc".
package main
import (
"fmt"
"regexp"
)
func replaceWholeWord(input string, patterns map[string]string) string {
for searchPattern, replacePattern := range patterns {
re, _ := regexp.Compile(`(?i)(^|\s)` + regexp.QuoteMeta(searchPattern) + `(\s|$)`)
input = re.ReplaceAllString(input, "${1}"+replacePattern+"${2}")
}
return input
}
func main() {
patterns := map[string]string{"Inc.": "Inc", "Incorp.": "Inc", "Incorporation": "Inc", ", Incorpa.": "Inc"}
fmt.Println(replaceWholeWord("ABC Inc.", patterns))
fmt.Println(replaceWholeWord("ABC Incorp.", patterns))
fmt.Println(replaceWholeWord("ABC InCorp.", patterns))
fmt.Println(replaceWholeWord("ABC InCorporation", patterns))
fmt.Println(replaceWholeWord("ABC , InCorpa.", patterns))
}
As you can see this performance intensive as the number of patterns increase. I want to build regular expression only once and do the search and replace operation. I am facing tough time to add the those multiple
patterns in a single regex without breaking the functionality.
Edit:
I modified my program to avoid building the regexes only if the word has the pattern, this way I have avoided to the performance hit.
Please feel free to close the question.

Answer 1

I am not a GO developer, but a single Regular Expression pattern for what you have shown would be:
(In(c|C)(\.|orp(\.|a\.|oration)))$
UPDATE: Found the GO way.
package main
import (
"fmt"
"regexp"
)
func main() {
re := regexp.MustCompile(`(?i)^(.*)(?:Inc(?:\.|orp(?:\.|a|oration)??\.))(.*)$`)
fmt.Println(re.ReplaceAllString("ABC Inc.", "${1}Inc${2}"))
fmt.Println(re.ReplaceAllString("ABC Incorp.", "${1}Inc${2}"))
fmt.Println(re.ReplaceAllString("ABC InCorporation.", "${1}Inc${2}"))
fmt.Println(re.ReplaceAllString("ABC InCorpa.", "${1}Inc${2}"))
}
ABC Inc
ABC Inc
ABC Inc
ABC Inc

Answer 2

Why not use an "or":
package main
import (
"fmt"
"regexp"
)
func main() {
re := regexp.MustCompile(`(?i)^(.*)(?:Inc\.|Incorp\.|Incorporation\.|Incorpa\.)(.*)$`)
fmt.Println(re.ReplaceAllString("ABC Inc.", "${1}Inc${2}"))
fmt.Println(re.ReplaceAllString("ABC Incorp.", "${1}Inc${2}"))
fmt.Println(re.ReplaceAllString("ABC InCorporation.", "${1}Inc${2}"))
fmt.Println(re.ReplaceAllString("ABC InCorpa.", "${1}Inc${2}"))
}
See Playground:
ABC Inc
ABC Inc
ABC Inc
ABC Inc

Answer 3

If all you 'search & replace' are done on whole words, you can simply turn your string into a slice of words and construct a new string which replaces each word present in your map with its counterpart:
var buffer bytes.Buffer
for _, word := range words {
if val, ok := patterns[word]; ok {
word = val
}
buffer.WriteString(word)
buffer.WriteString(" ")
}