Attributes

The Wolfram-named properties compute-engine tracks for a head's operator.

✓ checked against that system · ! checked, with disagreements (hover a chip)Wolfram LanguageAttributes!↗

Attributes(f)The subset of $\{Flat, HoldAll, Listable, Orderless\}$ $f$'s operator definition carries, and $Protected$ for a declared head, alphabetically.

Typed signatures

Type	Package	Applies
(symbol) -> list<symbol>	combinatorics	always

Domain: Collections

Details

• Maps compute-engine's own operator flags to the closest genuine Wolfram attribute name, and no further: $associative \to Flat$, $lazy \to HoldAll$, $broadcastable \to Listable$, $commutative \to Orderless$.
• Compute-engine's idempotent and involution flags are deliberately excluded: real algebraic properties it tracks for pattern matching, but not Wolfram Attributes names — Wolfram has no such entries, so reporting them would claim a fact that doesn't exist.
• HoldAll for lazy is an approximation: compute-engine's lazy means "operands arrive unevaluated", the effect of Wolfram's HoldAll without distinguishing it from HoldFirst/HoldRest/HoldAllComplete.
• Protected is reported for every head we declare — compute-engine's own and every package's — and for no symbol of your own. Nothing sets or clears it: SetAttributes and ClearAttributes refuse on a protected head.
• An undeclared symbol reads as no attributes.

Examples

Basic #

Add is Flat, HoldAll, Listable and Orderless on this engine, and Protected like every declared head

live ↗

In$\mathrm{Attributes}(\mathrm{Add})$Out$\bigl\lbrack\mathrm{Flat}, \mathrm{HoldAll}, \mathrm{Listable}, \mathrm{Orderless}, \mathrm{Protected}\bigr\rbrack$

An undeclared symbol has no attributes

live ↗

In$\mathrm{Attributes}(f)$Out$\bigl\lbrack\bigr\rbrack$

Properties #

A symbol with nothing set returns an empty list

live ↗

In$\mathrm{Attributes}(\mathrm{syms})$Out$\bigl\lbrack\bigr\rbrack$

live ↗

In$\mathrm{Attributes}(\mathrm{Attributes})$Out$\bigl\lbrack\mathrm{HoldAll}, \mathrm{Protected}\bigr\rbrack$

About

Examples	4
Checked against	Wolfram Language 2 agree2 differ
Crosswalk	Wolfram Language

See also: SetAttributes, ClearAttributes