To someone more experienced working with Regex pat...

# android

[aidanvii]

To someone more experienced working with Regex patterns.

I have a regex pattern that I use to sanitise bad json responses from our backend, replacing empty objects ({}) with null, and empty lists ([]) with null. The pattern is as follows:

Regex("""\{}|\[]""")

This compiles and works just fine in a unit test, but on android it crashes with:

Caused by: java.util.regex.PatternSyntaxException: Syntax error in regexp pattern near index 3
    \{}|\[]
       ^
        at java.util.regex.Pattern.compileImpl(Native Method)
        at java.util.regex.Pattern.compile(Pattern.java:1344)
        at java.util.regex.Pattern.<init>(Pattern.java:1328)
        at java.util.regex.Pattern.compile(Pattern.java:950)
        at kotlin.text.Regex.<init>(Regex.kt:89)

All I can surmise from this is that the underlying native implementation on Android is different.

[Rolando Lopez]

post an example of the text you’re trying to find over?

[aidanvii]

{ 
	"emptyObject" : {},
	"nonEmptyObject" : {
		"key" : "value"
	}
	"emptyList" : [],
	"nonEmptyList" : [
		"hello",
		"world"
	]
}

[aidanvii]

it fails when compiling the pattern, not when it processes the text

[aidanvii]

I've verified it works on standard JVM, but it's broken on Android

[aidanvii]

@Rolando Lopez dont worry, found the reason
https://stackoverflow.com/questions/45074813/regex-pattern-error-in-android-when-matching-closing-brace

[Rolando Lopez]

👍