6.7 Extending the Syntax of Signatures

(define-signature-form sig-form-id expr)

(define-signature-form (sig-form-id id) body ...+)

Binds sig-form-id for use within a define-signature form.

In the first form, the result of expr must be a transformer procedure. In the second form, sig-form-id is bound to a transformer procedure whose argument is id and whose body is the bodys. The result of the transformer must be a list of syntax objects, which are substituted for a use of sig-form-id in a define-signature expansion. (The result is a list so that the transformer can produce multiple declarations; define-signature has no splicing begin form.)

(struct/ctc id ([field contract-expr] ...) struct-option ...)

field	=	id
	\|	[id #:mutable]

struct-option	=	#:mutable
	\|	#:omit-constructor
	\|	#:omit-define-syntaxes
	\|	#:omit-define-values

For use with define-signature. The struct/ctc form works similarly to struct, but the constructor, predicate, field accessors, and field mutators are contracted appropriately.

top← prev up next →

1	Language Model
2	Syntactic Forms
3	Datatypes
4	Structures
5	Classes and Objects
6	Units
7	Contracts
8	Pattern Matching
9	Control Flow
10	Concurrency
11	Macros
12	Input and Output
13	Reflection and Security
14	Operating System
15	Memory Management
16	Unsafe Operations
17	Running Racket
	Bibliography
	Index

6.1	Creating Units
6.2	Invoking Units
6.3	Linking Units and Creating Compound Units
6.4	Inferred Linking
6.5	Generating A Unit from Context
6.6	Structural Matching
6.7	Extending the Syntax of Signatures
6.8	Unit Utilities
6.9	Unit Contracts
6.10	Single-Unit Modules
6.11	Single-Signature Modules
6.12	Transformer Helpers