[not loaded]expand.pl -- Prolog source-code transformation

This module specifies, together with dcg.pl, the transformation of terms as they are read from a file before they are processed by the compiler.

The toplevel is expand_term/2. This uses three other translators:

Conditional compilation
term_expansion/2 rules provided by the user
DCG expansion

Note that this ordering implies that conditional compilation directives cannot be generated by term_expansion/2 rules: they must literally appear in the source-code.

Term-expansion may choose to overrule DCG expansion. If the result of term-expansion is a DCG rule, the rule is subject to translation into a predicate.

Next, the result is passed to expand_bodies/2, which performs goal expansion.

expand_term(+Input, -Output) is det

expand_term(+Input, +Pos0, -Output, -Pos) is det

This predicate is used to translate terms as they are read from a source-file before they are added to the Prolog database.

var_property(+Var, ?Property)

True when Var has a property Key with Value. Defined properties are:

fresh(Fresh): Variable is first introduced in this goal and thus guaranteed to be unbound. This property is always present.
singleton(Bool): It true indicate that the variable appears once in the source. Note this doesn't mean it is a semantic singleton.
name(-Name): True when Name is the name of the variable.

expand_goal(+BodyTerm, +Pos0, -Out, -Pos) is det

expand_goal(+BodyTerm, -Out) is det

Perform macro-expansion on body terms by calling goal_expansion/2.

$expand_closure(+BodyIn, +ExtraArgs, -BodyOut) is semidet