12.6 Local Binding with Splicing Body

When a splicing binding form occurs in a top-level context or module context, its local bindings are treated similarly to definitions. In particular, syntax bindings are evaluated every time the module is visited, instead of only once during compilation as in let-syntax, etc.

If a definition within a splicing form is intended to be local to the splicing body, then the identifier should have a true value for the 'definition-intended-as-local syntax property. For example, splicing-let itself adds the property to locally-bound identifiers as it expands to a sequence of definitions, so that nesting splicing-let within a splicing form works as expected (without any ambiguous bindings).

Note that require transformers and provide transformers are not affected by syntax parameterization. While all uses of require and provide will be spliced into the enclosing context, derived import or export specifications will expand as if they had not been inside of the splicing-syntax-parameterize.

Additionally, submodules defined with module* that specify #f in place of a module path are affected by syntax parameterization, but other submodules (those defined with module or module* with a module path) are not.

Changed in version 6.11.0.1 of package base: Modified to syntax parameterize module* submodules that specify #f in place of a module path.