# Regex

Registered with `register_addon_regex(engine)`.

ECMAScript regex syntax. The compiled `regex` type is an addon type with a destructor that runs at scope exit.

## Construction

```cpp
regex re("[0-9]+");                       // ctor-form var-decl
regex re2 = regex("\\w+");                // assignment form
regex empty("[");                          // bad pattern → null handle
```

If the pattern fails to compile, the returned handle is 0 (null). Methods on a null handle are safe — they return false / empty.

## Methods

```cpp
bool   f = re.matches("12345")             // entire string matches pattern
bool   h = re.has_match("abc 123")         // any substring matches
string m = re.first("abc 123 def")         // first match text, or ""
array  all = re.find_all("a12 b345 c6")    // array<string> of all matches
string r = re.replace("a12b34", "#")       // "a#b#" (all matches replaced)
array  parts = re.split("a,b,c,d")         // split on matches
array  g = re.groups("name=42")            // [full, group1, group2, ...]
```

**Note:** `match` is a reserved keyword in Enma (used for pattern-matching expressions), so the single-match accessor is named `first`.

## Capture groups

`groups` returns an array where `[0]` is the full match and `[1..n]` are the capture groups in order:

```cpp
regex re = regex("([a-z]+)=([0-9]+)");
array g = re.groups("age=30");
// g[0] == "age=30", g[1] == "age", g[2] == "30"
```


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