String composition and formatting

rc.3 offers three related, statically typed tools for building text.

Join two strings with ..

Use concatenation when the operands are already strings:

local directory = "src"
local path = directory .. "/main.pop"

Both operands must be String. "count=" .. 3 is a type error, and + remains numeric-only.

Interpolate primitives with backticks

Use backticks for readable mixed text:

local count = 3
local ready = true
local summary = `count={count}, ready={ready}`

Interpolation accepts only String, Boolean, integer primitives, and floating-point primitives. Segments evaluate once from left to right. Arrays, tables, records, classes, functions, and arbitrary objects are rejected.

Backticks use {expression}, not JavaScript ${expression}. Escape literal punctuation with \{, \}, and ```.

Format one primitive with String(value)

Use explicit formatting when another operation needs a complete string value:

local count = 3
local prefix = "count="
local summary = prefix .. String(count)

Formatting is deterministic and locale-independent. There is no inherited toString, runtime type inspection, or dynamic fallback.

String composition and non-identity formatting may allocate. String(existingString) is identity.