CODEWITHSUNDEEP
stringluabracketslua-patterns
warspyking
warspyking

Reputation: 3113

String pattern, match the first, outermost pair of brackets?

So here's a trivial example, say I have an equation like

local equation = "((5*2)+3)-(3^5)"

And I want to capture "((5*2)+3)"

At first I tried

equation:match("%((.*)%)")

But * is greedy, so it captured the whole equation.

Then I tried

equation:match("%((.-)%)")

But - is lazy, and it captured "((5*2)"

Obviously I'm going about this wrong. How should I capture the brackets with a string pattern?

Upvotes: 2

Views: 175

Answers (1)

Yu Hao
Yu Hao

Reputation: 122383

What you are looking for is %b pattern, which matches balanced strings. In this example, you can use %b() to match a string that starts with (, and ends with the corresponding ):

equation:match("%b()")

Upvotes: 5

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