11.9 Expanding Top-Level Forms
Before top-level-form is expanded, its lexical context is enriched with namespace-syntax-introduce, just as for eval. Use syntax->datum to convert the returned syntax object into a printable datum.
Here’s an example of using expand on a module:
(parameterize ([current-namespace (make-base-namespace)]) (expand (datum->syntax #f '(module foo scheme (define a 3) (+ a 4)))))
Here’s an example of using expand on a non-top-level form:
(define-namespace-anchor anchor) (parameterize ([current-namespace (namespace-anchor->namespace anchor)]) (expand (datum->syntax #f '(delay (+ 1 2)))))
(expand-syntax stx) → syntax? stx : syntax?
(expand-once top-level-form) → syntax? top-level-form : any/c
Before top-level-form is expanded, its lexical context is enriched with namespace-syntax-introduce, as for eval.
(expand-syntax-once stx) → syntax? stx : syntax?
(expand-to-top-form top-level-form) → syntax? top-level-form : any/c
Before stx-or-sexpr is expanded, its lexical context is enriched with namespace-syntax-introduce, as for eval.
(expand-syntax-to-top-form stx) → syntax? stx : syntax?
11.9.1 Information on Expanded Modules
Information for an expanded module declaration is stored in a set of syntax properties (see Syntax Object Properties) attached to the syntax object:
'module-direct-requires —
a list of module path indexes (or symbols) representing the modules explicitly imported into the module. 'module-direct-for-syntax-requires —
a list of module path indexes (or symbols) representing the modules explicitly for-syntax imported into the module. 'module-direct-for-template-requires —
a list of module path indexes (or symbols) representing the modules explicitly for-template imported into the module. 'module-variable-provides —
a list of provided items, where each item is one of the following: symbol —
represents a locally defined variable that is provided with its defined name. (cons provided-sym defined-sym) —
represents a locally defined variable that is provided with renaming; the first symbol is the exported name, and the second symbol is the defined name. (list* module-path-index provided-sym defined-sym) —
represents a re-exported and possibly re-named variable from the specified module; module-path-index is either a module path index or symbol (see Compiled Modules and References), indicating the source module for the binding. The provided-sym is the external name for the re-export, and defined-sym is the originally defined name in the module specified by module-path-index.
'module-syntax-provides —
like 'module-variable-provides, but for syntax exports instead of variable exports. 'module-indirect-provides —
a list of symbols for variables that are defined in the module but not exported; they may be exported indirectly through macro expansions. Definitions of macro-generated identifiers create uninterned symbols in this list.