On this page:
syntax-warning
syntax-warning?
syntax-warning/  fix?
syntax-warning-message
syntax-warning-stx
syntax-warning-kind
syntax-warning-fix
warning-kind?
define-warning-kind
warning-kind-name
syntax-warn
syntax-warnings
read-syntax-warnings
read-syntax-warnings/  file
warning-config?
warning-config-merge
empty-warning-config
suppress
unsuppress
filter-unsuppressed-warnings
7.1

1 The Syntax Warnings Reference

 (require syntax/warn)
  packages: syntax-warn, syntax-warn-base

This module defines the programmatic API for adding syntax warnings to syntax objects. Warnings added via this library can be detected and manipulated by the tools outlined in The Syntax Warning Command Line Interface.

procedure

(syntax-warning #:message message    
  #:stx stx    
  [#:kind kind    
  #:fix fix])  syntax-warning?
  message : string?
  stx : syntax?
  kind : warning-kind? = #f
  fix : syntax? = #f
Constructs a syntax warning of kind kind that identifies stx as the syntax to blame and fix as a suggested replacement to use in place of stx. If kind is not provided, the warning doesn’t declare itself as having a particular kind. If fix is not provided, the warning makes no suggestions about how to resolve it.

procedure

(syntax-warning? v)  boolean?

  v : any/c
Predicate that recognizes syntax warnings.

procedure

(syntax-warning/fix? v)  boolean?

  v : any/c
Predicate that recognizes syntax warnings that include a suggested fix.

procedure

(syntax-warning-message warning)  string?

  warning : syntax-warning?

procedure

(syntax-warning-stx warning)  syntax?

  warning : syntax-warning?

procedure

(syntax-warning-kind warning)  (or/c warning-kind? #f)

  warning : syntax-warning?

procedure

(syntax-warning-fix warning)  (or/c syntax? #f)

  warning : syntax-warning?
Accessors for fields of syntax warnings.

Predicate recognizing warning kinds.

Binds id as a warning kind, a value that can be used to classify similar warnings. The warning kind has a name, which is the quoted form of id. The raco warn tool uses warning kind names in its output.

procedure

(warning-kind-name kind)  symbol?

  kind : warning-kind?
Returns the name of kind.

procedure

(syntax-warn stx warning)  syntax?

  stx : syntax?
  warning : syntax-warning?
Returns a syntax object equivalent to stx, but with warning attached as a syntax warning. The syntax warning need not blame stx as the source of the problem, this procedure merely provides the ability to attach warnings to syntax objects via syntax properties.

Examples:
> (define-warning-kind identifier-capitalization-warning)
> (syntax-warn #'(foo Bar)
               (syntax-warning #:message "Don't capitalize the \"Bar\" identifier"
                               #:stx #'foo
                               #:kind identifier-capitalization-warning))

#<syntax:eval:2:0 (foo Bar)>

procedure

(syntax-warnings stx)  (listof syntax?)

  stx : syntax?
Returns a list of all syntax warnings present in stx. This includes syntax warnings in any syntax objects nested within stx.

procedure

(read-syntax-warnings [#:input-port in 
  #:source-name source 
  #:namespace namespace]) 
  (listof syntax-warning?)
  in : input-port? = (current-input-port)
  source : any/c = (object-name in)
  namespace : namespace? = (current-namespace)
Constructs a syntax object from in using read-syntax, fully expands it using expand-syntax in namespace, and returns a list of all syntax warnings found in the fully expanded module.

procedure

(read-syntax-warnings/file filepath 
  [#:namespace namespace]) 
  (listof syntax-warning?)
  filepath : path-string?
  namespace : namespace? = (current-namespace)
Like read-syntax-warnings, but reads filepath as a module. Sets the current-directory to the directory part of filepath and uses filepath as the source name.

procedure

(warning-config? v)  boolean?

  v : any/c
Predicate that recognizes warning configurations, values used to control the behavior of tools that analyze syntax warnings. Configurations from different souces may be merged with warning-config-merge. Currently, warning configurations contain information about what kinds of warnings should be suppressed or unsuppressed (in the case of warnings that aren’t on by default). See suppress and unsuppress for details on how to construct these configurations.

procedure

(warning-config-merge config ...)  warning-config?

  config : warning-config?
Merges the given config values into a single warning configuration. In the case of more than one config attempting to suppress or unsuppress a warning kind, the rightmost configuration takes precedence. Merging any config with the empty-warning-config is equivalent to leaving the config unchanged. If no configurations are provided, returns empty-warning-config.

The empty warning config. Represents no changes from default behavior.

procedure

(suppress kind ...)  warning-config?

  kind : (or/c warning-kind? symbol?)

procedure

(unsuppress kind ...)  warning-config?

  kind : (or/c warning-kind? symbol?)
Constructs a warning configuration where warnings of each of the given kinds is either suppressed or unsuppressed, depending on the function called. Warnings may be suppressed using an explicit warning kind value or suppressed by a symbol representing the name of the warning kind to suppress. Symbols allow configuration sources to construct warning kind configs without access to the warning kind bindings. To suppress some warnings and unsuppress others, see warning-config-merge.

procedure

(filter-unsuppressed-warnings warnings 
  config) 
  (listof syntax-warning?)
  warnings : (listof syntax-warning?)
  config : warning-config?
Returns all the syntax warnings in warnings that are not suppressed according to config.