expressionlike

Expressionlike is a term used in programming language theory and formal linguistics to describe objects that have the structural and operational characteristics of expressions, as opposed to statements or values. An expressionlike object can typically be constructed from variables, constants, and operators, and it participates in substitution and evaluation rules in a way that resembles ordinary expressions.

In compiler design and formal grammars, expressionlike nodes appear in abstract syntax trees to denote computations that yield a value. They are distinguished from statementlike nodes, which perform actions without producing a direct result. In symbolic computation systems, expressionlike objects can be manipulated symbolically, rewritten, simplified, or postponed for evaluation.

Typical properties include: the ability to be composed from other expressionlike objects, to be reduced or rewritten under defined rules, and to have a representation that can be printed or serialized. The term is usually used descriptively rather than as a formal category, and its precise meaning can vary by language or framework.

Example: in a toy language, an AST node Add(x, y) is expressionlike, because it represents a computation that could yield the value of x plus y. A node representing a print statement or an assignment is not expressionlike, since it is intended to affect state rather than produce a value.

See also: expression, term, value, abstract syntax tree, syntax category. Notes: the term is informal and not universally standardized, and its interpretation depends on context.