▼ |  | Unstable: May Change Without Warning

1 | Guidelines for Developing unstable Libraries
2 | Automata: Compiling State Machines
3 | Bytes
4 | Contracts
5 | Contracts for Macro Subexpressions
6 | Debugging
7 | Definitions
8 | Errors
9 | Filesystem
10 | Find
11 | Flonums
12 | Futures
13 | Functions
14 | Hash Tables
15 | Interface-Oriented Programming for Classes
16 | Lazy Require
17 | Lists
18 | Logging
19 | Macro Testing
20 | Mark Parameters
21 | Match
22 | Open place expressions
23 | Options
24 | Parameter Groups
25 | Pretty-Printing
26 | Re-Contracting Identifiers
27 | Sandbox
28 | Sequences
29 | Strings
30 | Structs
31 | Struct Printing
32 | Syntax
33 | Temporal Contracts: Explicit Contract Monitors
34 | Unix Domain Sockets
35 | 2D Syntax
36 | GUI Libraries

► | 32 | Syntax

32.1 | Syntax Object Source Locations

On this page:

explode-module-path-index
phase-of-enclosing-module
make-variable-like-transformer
format-unique-id
syntax-within?
syntax-map
32.1`` Syntax Object Source Locations
syntax-source-directory
syntax-source-file-name

5.3.6
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### 32`` Syntax

Ryan Culpepper <ryanc@racket-lang.org>

This library is unstable; compatibility will not be maintained. See Unstable: May Change Without Warning for more information.

(require unstable/syntax)

> > procedure

> > (explode-module-path-index mpi)

> → (listof (or/c module-path? resolved-module-path? #f))
> mpi : module-path-index?

Unfolds mpi using module-path-index-split, returning a list of the relative module paths together with the terminal resolved module path or #f for the “self” module.

Examples:

> > (explode-module-path-index (car (identifier-binding #'lambda)))
> '("kw.rkt" racket/private/pre-base #f)
> > (explode-module-path-index (caddr (identifier-binding #'lambda)))
> '(racket/base #f)
> > (explode-module-path-index (car (identifier-binding #'define-values)))
> '('#%kernel #f)

> > syntax

> > (phase-of-enclosing-module)

Returns the phase level of the module in which the form occurs (and for the instantiation of the module in which the form is executed). For example, if a module is required directly by the “main” module (or the top level), its phase level is 0. If a module is required for-syntax by the “main” module (or the top level), its phase level is 1.

Examples:

> > (module helper racket
> (require unstable/syntax)
> (displayln (phase-of-enclosing-module)))

> > (require 'helper)
> 0

> > (require (for-meta 1 'helper))
> 1

> > procedure

> > (make-variable-like-transformer |  | reference-stx |
> > | [ | setter-stx]) |

> → set!-transformer?
> reference-stx : syntax?
> setter-stx : (or/c syntax? #f) = #f

Creates a transformer that replaces references to the macro identifier with reference-stx. Uses of the macro in operator position are interpreted as an application with reference-stx as the function and the arguments as given.

If the macro identifier is used as the target of a set! form, then the set! form expands into the application of setter-stx to the set! expression’s right-hand side, if setter-stx is syntax; otherwise, the identifier is considered immutable and a syntax error is raised.

Examples:

> > (define the-box (box add1))

> > (define-syntax op
> (make-variable-like-transformer
> #'(unbox the-box)
> #'(lambda (v) (set-box! the-box v))))

> > (op 5)
> 6
> > (set! op 0)

> > op
> 0

> > > The subsequent bindings were added by Vincent St-Amour <stamourv@racket-lang.org>.

> > procedure

> > (format-unique-id |  | lctx |  |  |  |
> > |  | fmt |  |  |  |
> > |  | v ... |  |  |  |
> > | [ | #:source src |  |  |  |
> > |  | #:props props |  |  |  |
> > |  | #:cert cert]) |  | → |  | identifier?

> lctx : (or/c syntax? #f)
> fmt : string?
> v : (or/c string? symbol? identifier? keyword? char? number?)
> src : (or/c syntax? #f) = #f
> props : (or/c syntax? #f) = #f
> cert : (or/c syntax? #f) = #f

Like format-id, but returned identifiers are guaranteed to be unique.

> > procedure

> > (syntax-within? a b) → boolean?

> a : syntax?
> b : syntax?

Returns true is syntax a is within syntax b in the source. Bounds are inclusive.

> > > The subsequent bindings were added by Sam Tobin-Hochstadt <samth@racket-lang.org>.

> > procedure

> > (syntax-map f stxl ...) → (listof A)

> f : (-> syntax? A)
> stxl : syntax?

Performs (map f (syntax->list stxl) ...).

Example:

> > (syntax-map syntax-e #'(a b c))
> '(a b c)

> > > The subsequent bindings were added by Carl Eastlund <cce@racket-lang.org>.

#### 32.1`` Syntax Object Source Locations

> > procedure

> > (syntax-source-directory stx) → (or/c path? #f)

> stx : syntax?

> > procedure

> > (syntax-source-file-name stx) → (or/c path? #f)

> stx : syntax?

These produce the directory and file name, respectively, of the path with which stx is associated, or #f if stx is not associated with a path.

Examples:

> (define loc
> (list (build-path "/tmp" "dir" "somewhere.rkt")
> #f #f #f #f))

> (define stx1 (datum->syntax #f 'somewhere loc))

> > (syntax-source-directory stx1)
> #<path:/tmp/dir/>
> > (syntax-source-file-name stx1)
> #<path:somewhere.rkt>

> (define stx2 (datum->syntax #f 'nowhere #f))

> > (syntax-source-directory stx2)
> #f
> > (syntax-source-directory stx2)
> #f

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