Schemas Grammar Nodes Builtins Standard Library

The task-oriented overview below groups every builtin once. The builtin name list that follows is character-code sorted, and the main table is also exhaustive; each Name link in the main table opens a dedicated reference page.

The Stack effect column uses a compact notation: (a b -- c d). The left side lists consumed inputs from lower stack position to top, the right side lists produced outputs in the same order, and an empty side means none.

Some builtin names are historical. The dedicated builtin pages state the exact language semantics where a name does not directly express them.

The Description column summarizes semantics and notable special cases. Dedicated builtin pages give the full behavior, constraints, and examples.

Example output sections record only MPL-level output. Module-loading wrapper lines and lines such as <BASE> or Compilation succeeded are omitted.

Task-oriented overview

Builtin names

Name Stack effect Description
! (value ordinal structTarget --) Writes one selected item by zero-based ordinal, with the value and ordinal before the Struct target. Both inputs are dereferenced first.
& (prefix suffix -- text) Concatenates two known Text values.
* (multiplicand multiplier -- product) Multiplies two numeric values.
+ (left right -- sum) Adds two numeric values.
- (minuend subtrahend -- difference) Subtracts the second numeric value from the first.
/ (dividend divisor -- quotient) Divides numeric values within the same schema; Whole division stays whole, while Real schemas use floating division.
< (leftValue rightValue -- isLess) Tests whether the left value is less than the right one for supported same-schema numbers or known Text.
= (leftValue rightValue -- isEqual) Tests dereferenced value equality for Cond, numeric, and Text values of the same schema; Ref values are dereferenced before comparison.
> (leftValue rightValue -- isGreater) Tests whether the left value is greater than the right one for supported same-schema numbers or known Text.
@ (ordinal structValue -- selectedItem) Reads one selected item by zero-based ordinal, with the ordinal before the Struct value. Callable items are read, not called.
DEBUG (-- debugCondition) Pushes a known Cond that reports whether debug mode is enabled.
FALSE (-- falseCondition) Pushes the false condition value.
LF (-- lineFeed) Pushes a line-feed Text constant.
TRUE (-- trueCondition) Pushes the true condition value.
^ (base exponent -- power) Raises one Real value to another of the same schema and keeps that real schema in the result.
addressToReference (address modelValue -- reconstructedValue) Builds a typed result from a numeric storage address and a model value. Ref-like model values keep their schema, direct non-Ref-like model values produce a Ref to the model schema, and zero addresses produce the corresponding known nil result.
alignment (schema -- alignment) Known Natx alignment requirement of the dereferenced schema; current contents do not participate.
and (leftOperand rightOperand -- combinedValue) Combines two Cond or Whole values with bitwise or logical AND semantics.
array (item itemCount -- array) Creates a repeated-item List when count is positive; count 0 yields the empty Tuple ().
attribute (attribute --) Consumes one known Text attribute string and produces no value.
call (callable -- calledResult) Calls an already-selected Block, Code, callable Dict, or known Text through a call boundary. No selection happens inside the builtin.
callField (dict name -- fieldResult) Known-name data-input Dict field selection with .NAME-style field handling. Callable fields are called; non-callable fields are read.
cast (value schema -- convertedValue) Casts a Cond or numeric value to the numeric schema selected by the schema input.
ceil (value -- ceilingValue) Rounds a Real value upward and keeps the same real schema.
code? (schema -- isBlock) Despite its name, tests whether the schema is Block, not Code; codeRef? is the Code test.
codeRef (inputsSchema output options -- code) Constructs a Code schema from an input descriptor, an output descriptor, and an options descriptor, then pushes a known NIL Code value of that schema.
codeRef? (schema -- isCode) Tests whether the schema is Code; value usability and NIL status do not participate.
const (value -- immutableView) Current stack-value immutable-view conversion; only Ref inputs change view, while Code, Text, and Meta are returned unchanged.
cos (angle -- cosine) Computes the cosine of a Real value and keeps the same real schema.
def (value name --) Creates a named local or field using a known Text name.
dynamic (value -- dynamicValue) Current stack-value forgotten-contents conversion; keeps the same schema and general value kind while erasing current value knowledge where applicable.
exportFunction (inputsSchema output options callable name --) Exports a named function built from a Block and a signature, and creates an immediately usable Code name in the current module.
failCompilation (--) Aborts compilation immediately.
fieldCount (schema -- itemCount) Schema item count for a Struct; duplicate names, unnamed items, and items without runtime storage still count separately, and valid ordinals run 0 through itemCount - 1.
fieldIndex (schema itemName -- ordinal) Name-to-ordinal lookup on a Struct schema; Dict uses last-match lookup, including "" for the last unnamed item, while List and Tuple accept only "" and select the last item.
fieldIsRef (schema ordinal -- isRefLike) Selected-item schema predicate; tests whether the item schema is Ref, Code, or Text. Current field contents, knownness, and NIL status do not participate, so read results can differ for In-place items.
fieldIsVirtual (schema ordinal -- hasNoStorage) Schema predicate for the selected item; tests whether it has no runtime field storage, including virtual and Meta items.
fieldName (schema ordinal -- itemName) Ordinal-to-name lookup on a Struct schema; repeated names remain repeated, and unnamed items are reported as the empty Text "".
fieldRead (structValue ordinal -- selectedItem) Data-input ordinal selection and read, with the Struct value before the ordinal. Callable items are read, not called.
fieldWrite (value structTarget ordinal --) Data-input ordinal selection and write, with the value and Struct target before the ordinal. Both value and target are dereferenced first.
floor (value -- floorValue) Rounds a Real value downward and keeps the same real schema.
getCallTrace (-- callTrace) Returns an immutable Ref to the current top call-trace item, or NIL when unavailable.
has (schema itemName -- hasName) Known-name presence test on a schema; any matching Dict field is enough, "" also matches unnamed items, List/Tuple match only "", and no ordinal is chosen.
if (condition trueCallable falseCallable -- branchResult) Selects between two already-selected Block branches by Cond. Unknown conditions require both branches to be compiled and merged.
importFunction (inputsSchema output options name --) Declares or imports a named function with the supplied signature and binds it in the current scope as a usable Code local. Repeating the same signature still creates another current-scope name.
importVariable (schema name --) Creates a local that refers to an external variable of the requested non-Meta schema; the schema may come from a value or Ref, and the created local is treated as unknown.
is (leftValue rightValue -- isIdentityLike) Tests identity-like equality for Ref, Text, and Code values of the same dereferenced schema; same-schema In-place values still give FALSE.
isCombined (schema -- isCombined) Tests whether the dereferenced schema is any Struct. That is Dict, List, or Tuple, including (); zero item count does not matter.
isConst (value -- isConst) Current stack-value immutability predicate; tests the current stack value itself, and const or unconst change its result only for Ref inputs.
isDirty (value -- isDirty) Current stack-value instability predicate; exact opposite of stable?. Forgotten contents alone do not make a value dirty.
isDynamic (value -- isDynamic) Current stack-value forgotten-contents predicate; same predicate as unknownStable?, and Text, Code, and Meta values still report FALSE.
isRef (value -- value isRefLike) Current stack-value Ref-like predicate; preserves the current stack value and treats Ref, Code, and Text as Ref-like regardless of current knownness or NIL status.
isStatic (value -- isKnown) Historical name for the current stack-value knownness predicate; knownness follows known non-NIL Ref targets, same as known?.
known? (value -- isKnown) Preferred name for the current stack-value knownness predicate; knownness follows known non-NIL Ref targets, same as isStatic.
log (argument -- naturalLogarithm) Computes the natural logarithm of a Real value and keeps the same real schema.
log10 (argument -- decimalLogarithm) Computes the base-10 logarithm of a Real value and keeps the same real schema.
loop (callable -- loopState) Repeatedly calls one already-selected Block through a call boundary. Its stack effect must be (A -- A Cond).
lshift (value shiftCount -- shiftedValue) Performs a bitwise left shift on a Whole value and keeps the same schema.
managed? (schema -- isManaged) Tests whether the dereferenced schema has managed lifetime behavior; this is a schema property, not a current-value state or stability test.
manuallyDestroyVariable (value --) Designated-storage destruction without freeing the storage address.
manuallyInitVariable (value --) Designated-storage initialization in existing storage without allocating the storage address.
mod (dividend divisor -- remainder) Computes the remainder of numeric division; signed Int, unsigned Nat, and Real values each follow their own remainder semantics.
neg (value -- negatedValue) Negates a signed Int or Real value and keeps the same schema.
new (value -- newValue) Fresh-value creation from a current stack value. Ref inputs use current referenced contents, so immutable Ref values copy, mutable Ref values move, and known NIL Ref values are invalid.
newVarOfTheSameType (schema -- newValue) Fresh-value creation from only the dereferenced input schema. Current contents, access path, and NIL status do not participate, so known NIL Ref inputs can still be valid.
or (leftOperand rightOperand -- combinedValue) Combines two Cond or Whole values with bitwise or logical OR semantics.
overload (--) Creates a pending overload specifier for the next successful name creation. It applies to NAME: ...;, def, exportFunction, and importFunction, and is invalid for importVariable.
printCompilerMessage (message --) Prints a known Text message during compilation and appends one line-feed character.
printStack (--) Prints the current data stack in canonical formatter form; it does not itself pop stack values.
printStackTrace (--) Prints the current scope stack as file path, line, column, and node source text information.
private (--) Creates a pending visibility specifier for the next successful name creation. It applies to NAME: ...;, def, exportFunction, importFunction, and importVariable, so use does not import that name from the module.
raiseStaticError (message --) Raises a compile-time error with the given known Text message.
rshift (value shiftCount -- shiftedValue) Performs a bitwise right shift on a Whole value and keeps the same schema.
same (leftSchema rightSchema -- isSameSchema) Tests whether two dereferenced schemas are exactly the same; this is schema equality only, not runtime-value equality, and matching schemaName text is not enough.
schemaName (schema -- reportedName) Returns the default formatted name of the dereferenced schema, unless a Dict schema overrides it with a static Text field named SCHEMA_NAME. Matching reported names still do not imply same.
set (value destination --) Already-selected destination replacement after dereferencing both inputs. No selection happens inside the builtin, and a Ref destination rewrites the referenced object itself rather than a stored Ref value.
sin (angle -- sine) Computes the sine of a Real value and keeps the same real schema.
sqrt (radicand -- squareRoot) Computes the square root of a Real value and keeps the same real schema.
stable? (value -- isStable) Current stack-value stability predicate; exact opposite of isDirty. Forgotten contents alone do not make a value unstable.
static (--) Reserved builtin name. Used by itself, it consumes nothing, produces nothing, and has no documented standalone effect, and it does not set or clear any pending declaration specifier. The declaration modifier that marks the next local as static is virtual.
storageAddress (value -- address) Current stack-value storage-address query; known NIL Ref, Text, and Code values yield 0nx.
storageSize (schema -- size) Known Natx storage size of the dereferenced schema; current contents do not participate.
textSize (text -- size) Returns the UTF-8 code-unit (byte) count of a Text value as known or unknown Natx; known NIL text is invalid.
textSplit (text -- characterList) Splits known Text by decoded UTF-8 characters into one-character Text items. Empty text yields the empty Tuple ().
ucall (callable -- inlineResult) Processes an already-selected Block or known Text inline in the current scope.
uif (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.
unconst (value -- mutableView) Current stack-value mutable-view conversion; only Ref inputs change view, while Code, Text, and Meta are returned unchanged.
unknownStable? (value -- isUnknownStable) Same current stack-value forgotten-contents predicate as isDynamic.
use (moduleDescriptor --) Imports public names from a module path named by known Text, or imports one selected public name when the last dot after the last path separator separates the module path from that name.
virtual (--) Creates a pending static specifier for the next successful local creation through NAME: ...; or def. It is invalid for exportFunction, importFunction, and importVariable; virtual is the historical name for this declaration modifier.
virtual? (schema -- isMeta) Despite its name, it does not test whether a local or field was declared with virtual; it tests whether the schema is Meta.
xor (leftOperand rightOperand -- combinedValue) Combines two Cond or Whole values with logical exclusive-OR or bitwise XOR semantics.
~ (value -- invertedValue) Performs logical NOT for Cond or bitwise complement for a Whole value.