String interpolation

String literals support interpolation via ${...}. Any expression is valid inside the braces.

let name = "Alice"
let age  = 30

let greeting = "Hello, ${name}!"
let summary  = "${name} is ${age} years old"
let calc     = "${a} * ${b} = ${a * b}"

The embedded expression is evaluated and converted to a String via the same stringification rules used by debug.

Any expression works

"path = ${home.join("/")}"              // method call
"factorial(5) = ${factorial(5)}"         // function call
"${if x > 0 { "positive" } else { "negative" }}"    // if-expression
"${match status { Ok(v) => v.toString(), Error(_) => "err" }}"   // match

If the expression is itself a string, interpolation recurses naturally; no special handling is required.

Escapes

String literals support the usual escapes plus one for the interpolation metacharacter:

Escape	Produces
\"	double-quote
\\	backslash
\n	newline
\r	carriage return
\t	tab
\$	literal $

let literal = "price is \$${price}"     // price is $10

Nesting and quoting

Double quotes inside an interpolated expression do not need escaping; the interpolation delimiter is }, not ".

debug "name=${user.map(fn(u) { u.name }).unwrapOr("anonymous")}"

Tip

If an interpolation expression grows past one line, pull it into a let binding first. Readability beats clever one-liners.

Raw strings

Raw string literals (without escape processing) are not currently supported. Use explicit escapes where needed.

Codegen

Interpolations desugar into string concatenation at compile time. The generated Apex does not use String.format; it uses the + operator with stringified operands, which matches Apex’s own preferred idiom.