racket/collects/scribblings/reference/stx-comp.scrbl
2008-02-20 14:17:37 +00:00

172 lines
6.7 KiB
Racket

#lang scribble/doc
@(require "mz.ss")
@title[#:tag "stxcmp"]{Syntax Object Bindings}
@defproc[(bound-identifier=? [a-id syntax?][b-id syntax?]
[phase-level (or/c exact-integer? false/c)
(syntax-local-phase-level)])
boolean?]{
Returns @scheme[#t] if the identifier @scheme[a-id] would bind
@scheme[b-id] (or vice-versa) if the identifiers were substituted in a
suitable expression context at the @tech{phase level} indicated by
@scheme[phase-level], @scheme[#f] otherwise. A @scheme[#f] value for
@scheme[phase-level] corresponds to the @tech{label phase level}.}
@defproc[(free-identifier=? [a-id syntax?][b-id syntax?]
[phase-level (or/c exact-integer? false/c)
(syntax-local-phase-level)])
boolean?]{
Returns @scheme[#t] if @scheme[a-id] and @scheme[b-id] access the same
lexical, module, or top-level binding at the @tech{phase level}
indicated by @scheme[phase-level]. A @scheme[#f] value for
@scheme[phase-level] corresponds to the @tech{label phase level}.
``Same module binding'' means that the identifiers refer to the same
original definition site, not necessarily the @scheme[require] or
@scheme[provide] site. Due to renaming in @scheme[require] and
@scheme[provide], the identifiers may return distinct results with
@scheme[syntax-e].}
@defproc[(free-transformer-identifier=? [a-id syntax?][b-id syntax?]) boolean?]{
Same as @scheme[(free-identifier=? a-id b-id (add1 (syntax-local-phase-level)))].}
@defproc[(free-template-identifier=? [a-id syntax?][b-id syntax?]) boolean?]{
Same as @scheme[(free-identifier=? a-id b-id (sub1 (syntax-local-phase-level)))].}
@defproc[(free-label-identifier=? [a-id syntax?][b-id syntax?]) boolean?]{
Same as @scheme[(free-identifier=? a-id b-id #f)].}
@defproc[(check-duplicate-identifier [ids (listof identifier?)])
(or/c identifier? false/c)]{
Compares each identifier in @scheme[ids] with every other identifier
in the list with @scheme[bound-identifier=?]. If any comparison
returns @scheme[#t], one of the duplicate identifiers is returned (the
first one in @scheme[ids] that is a duplicate), otherwise the result
is @scheme[#f].}
@defproc[(identifier-binding [id-stx syntax?]
[phase-level (or/c exact-integer? false/c)
(syntax-local-phase-level)])
(or/c (one-of 'lexical #f)
(listof module-path-index?
symbol?
module-path-index?
symbol?
(one-of/c 0 1)
(or/c exact-integer? false/c)
(or/c exact-integer? false/c)))]{
Returns one of three kinds of values, depending on the binding of
@scheme[id-stx] at the @tech{phase level} indicated by
@scheme[phase-level] (where a @scheme[#f] value for
@scheme[phase-level] corresponds to the @tech{label phase level}):
@itemize{
@item{The result is @indexed-scheme['lexical] if @scheme[id-stx]
has a @tech{local binding}. If @scheme['lexical] is produced for
any @scheme[phase-level] value, then it is produced for all
@scheme[phase-level] values.}
@item{The result is a list of six items when @scheme[id-stx]
has a @tech{module binding}: @scheme[(list _source-mod _source-id
_nominal-source-mod _nominal-source-id _source-phase _import-phase
_nominal-export-phase)].
@itemize{
@item{@scheme[_source-mod] is a module path index (see
@secref["modpathidx"]) that indicates the defining module.}
@item{@scheme[_source-id] is a symbol for the identifier's name
at its definition site in the source module. This can be
different from the local name returned by
@scheme[syntax->datum] for several reasons: the identifier is
renamed on import, it is renamed on export, or it is
implicitly renamed because the identifier (or its import) was
generated by a macro invocation.}
@item{@scheme[_nominal-source-mod] is a module path index (see
@secref["modpathidx"]) that indicates the module
@scheme[require]d into the context of @scheme[id-stx] to
provide its binding. It can be different from
@scheme[_source-mod] due to a re-export in
@scheme[_nominal-source-mod] of some imported identifier. If
the same binding is imported in multiple ways, an arbitrary
representative is chosen.}
@item{@scheme[_nominal-source-id] is a symbol for the
identifier's name as exported by
@scheme[_nominal-source-mod]. It can be different from
@scheme[_source-id] due to a renaming @scheme[provide], even if
@scheme[_source-mod] and @scheme[_nominal-source-mod] are the
same.}
@item{@scheme[_source-phase] is @scheme[1] if the source
definition is for-syntax, @scheme[0] otherwise.}
@item{@scheme[_import-phase] is @scheme[0] if the binding
import of @scheme[_nominal-source-mode] is a plain
@scheme[require], @scheme[1] if it is from a
@scheme[for-syntax] import, etc.}
@item{@scheme[_nominal-export-phase] is the @tech{phase level}
of the export from @scheme[_nominal-source-mod].}
}}
@item{The result is @scheme[#f] if @scheme[id-stx]
has a @tech{top-level binding}.}
}}
@defproc[(identifier-transformer-binding [id-stx syntax?])
(or/c (one-of 'lexical #f)
(listof module-path-index?
symbol?
module-path-index?
symbol?
(one-of/c 0 1)
(or/c exact-integer? false/c)
(or/c exact-integer? false/c)))]{
Same as @scheme[(identifier-binding id-stx (add1 (syntax-local-phase-level)))].}
@defproc[(identifier-template-binding [id-stx syntax?])
(or/c (one-of 'lexical #f)
(listof module-path-index?
symbol?
module-path-index?
symbol?
(one-of/c 0 1)
(or/c exact-integer? false/c)
(or/c exact-integer? false/c)))]{
Same as @scheme[(identifier-binding id-stx (sub1 (syntax-local-phase-level)))].}
@defproc[(identifier-label-binding [id-stx syntax?])
(or/c (one-of 'lexical #f)
(listof module-path-index?
symbol?
module-path-index?
symbol?
(one-of/c 0 1)
(or/c exact-integer? false/c)
(or/c exact-integer? false/c)))]{
Same as @scheme[(identifier-binding id-stx #f)].}