Strings

Strings in double quotes, "hello, world", understand escapes like \n, \t, \\ and \". Backticks avoid escaping:

> println("hello,\n world")
hello,
 world
> println(`hello,\n world`)
hello,\n world

Extended delimiters

You can add backslashes before and after the outer quotes to avoid escaping inner ones:

> println(\"hello, "world""\)
hello, "world"
> println(\`hello, `world``\)
hello, `world`

In double quotes with backslashes, escapes need the number of backslashes to match inside and out:

> println(\\"hello,\n world"\\)
hello,\n world
> println(\\"hello,\\n world"\\)
hello,
 world

Triple quotes

Triple-quote strings – with both """ and triple backticks – support escaping and extended delimiters in the same way. They also strip the indentation from the beginning of each line:

{
  a = """
  hello, world
  """
  b = "hello, world"
  test a == b
}

Template strings

A prefix on a string alters how it's interpreted, like a macro. Single-quote (backtick) templates put the tag before the string; triple-quote templates put it just after the opening quotes:

r`\d`
js`return 2+2`

```js
console.log("hello, world")
```

r gives you regular expressions and js inline JavaScript (see Calling JavaScript).

Regular expressions

Test a string with contains? and iterate over matches (and capture groups) with matches:

> contains?("1, 2, 3", r`\d`)
true
> collect(matches("1, 2, 3", r`\d`))
[["1"], ["2"], ["3"]]

Characters and encodings

Strings are sequences of unicode scalar values, represented as 21-bit integers in the Char type:

> collect("hello 🔥")
[c"h", c"e", c"l", c"l", c"o", c" ", c"🔥"]
> "hello 🔥"[7] == c"🔥"
true
> UInt32("hello 🔥"[7])
0x0001f525

Strings are abstracted from their storage format, and indexing is linear-time. You can get data views with constant-time access to code points, in a given encoding, with chars, utf16 and utf8:

> map(chars("🔥"), UInt32)
[0x0001f525]
> collect(utf16("🔥"))
[0xd83d, 0xdd25]
> collect(utf8("🔥"))
[0xf0, 0x9f, 0x94, 0xa5]

Note that graphemes may be composed from multiple Chars:

> collect("🤦🏼‍♂️")
[c"🤦", c"🏼", c"‍", c"♂", c"️"]

Building strings

string(x) converts a value to a string, and concat joins strings together:

concat("hello, ", "world")
string(42) # "42"

There's no string interpolation syntax yet; use concat and string.