call (callable -- calledResult)

Inputs

• callable: Already-selected value or Ref whose dereferenced input is Block, Code, callable Dict, or known Text.

Outputs

• calledResult: Result produced by calling callable.

Calls one already-selected stack callable. No name lookup or field selection happens inside the builtin.

call performs a call boundary. Locals created inside the called logic do not remain available afterward.

Behavior

• The callable must already be on the data stack.
• Any remaining data inputs required by that callable must already be below it on the data stack.
• Supported inputs are Block, Code, callable Dict, and known Text.
• Stored Block, Code, and callable Dict values are obtained via .@NAME or @NAME when the stored callable itself must be pushed. Plain .NAME or NAME may already call the stored value before call runs. Known Text locals differ: plain mention already pushes the Text value, so textLocal call is valid.
• For a callable Dict already on the data stack, call invokes its CALL field directly. PRE is not used, because the Dict value is already selected before call runs.
• A known NIL Code is invalid.
• Unknown Text is invalid.

When the input is a callable Dict, that callable Dict's fields are available for direct scope lookup during CALL. For a non-Meta non-static callable Dict, a special name closure is also available and references that same Dict. There is no separate self name here, because no outer field-selection step occurs inside call.

Known Text inputs are interpreted as MPL code text and then called through the same call boundary.

Example

{} 0 {} [
  "-- block uses stack values below it --" printCompilerMessage
  5 [2 +] call printStack _:;

  "-- call uses CALL directly on an already selected Dict --" printCompilerMessage
  runner: {
    factor: 3;
    PRE: [FALSE];
    CALL: [factor *];
  };
  7 @runner call printStack _:;

  "-- read Code value first, then call it --" printCompilerMessage
  codeLocal: {} () {} codeRef;
  ["-- code --" printCompilerMessage] !codeLocal
  @codeLocal call

  "-- known text from stack --" printCompilerMessage
  9 «1 +» call printStack _:;

  "-- known text local may be mentioned plainly --" printCompilerMessage
  textLocal: «2 +»;
  8 textLocal call printStack _:;

  0
] "main" exportFunction

Expected Output During Compilation

-- block uses stack values below it --
7
-- call uses CALL directly on an already selected Dict --
21
-- read Code value first, then call it --
-- code --
-- known text from stack --
10
-- known text local may be mentioned plainly --
10

See also

• callField builtin (dict name -- fieldResult) Selects a Dict field by known Text name and then applies .NAME-style semantics. Callable fields are called; non-callable fields are read.
• if builtin (condition trueCallable falseCallable -- branchResult) Selects between two already-selected Block branches by Cond. Unknown conditions require both branches to be compiled and merged.
• loop builtin (callable -- loopState) Repeatedly calls one already-selected Block through a call boundary. Its stack effect must be (A -- A Cond).
• ucall builtin (callable -- inlineResult) Processes an already-selected Block or known Text inline in the current scope.
• uif builtin (condition trueCallable falseCallable -- branchResult) Selects between two already-selected Block branches by a known Cond and processes the selected branch inline. No branch-output merge occurs.