& (prefix suffix -- text)

Inputs

• prefix: Leading Text object.
• suffix: Trailing Text object.

Outputs

• text: Concatenation result.

This builtin is the text-concatenation operator. Both inputs must be known, non-NIL Text objects at compile time, so the result is also a known Text object. Unknown Text objects and known NIL Text objects are rejected.

Known multi-line text is formed by combining & with LF.

Behavior

• If suffix is empty, the builtin reuses prefix as the result.
• If prefix is empty, the builtin reuses suffix as the result.
• If both inputs are non-empty, the builtin creates a new known Text object containing the concatenated UTF-8 code units.
• The builtin does not split, normalize, or reinterpret text. It concatenates the UTF-8 byte sequences exactly as supplied.

Example

{} 0 {} [
  "-- concat --" printCompilerMessage
  "pre" "fix" & printStack _:;

  "-- empty prefix --" printCompilerMessage
  "" "fix" & printStack _:;

  "-- empty suffix --" printCompilerMessage
  "pre" "" & printStack _:;

  0
] "main" exportFunction

Expected Output During Compilation

-- concat --
"prefix"
-- empty prefix --
"fix"
-- empty suffix --
"pre"

See also

• LF builtin (-- lineFeed) Pushes a line-feed Text constant.
• attribute builtin (attribute --) Consumes one known Text attribute string and produces nothing.
• textSize builtin (text -- size) Returns the UTF-8 code-unit (byte) count of a Text object as known or unknown Natx; known NIL text is invalid.
• textSplit builtin (text -- characterList) Splits known Text by decoded UTF-8 characters into one-character Text items. Empty text yields the empty Tuple ().