1 Accessing Check Syntax Programmatically

(require drracket/check-syntax)
	package: drracket-tool-lib

procedure
(show-content file-or-stx
[ #:fully-expanded? fully-expanded?
#:namespace namespace])
→ (listof vector?)
   file-or-stx :
(or/c path-string?
      (and/c syntax?
             (λ (x) (path-string? (syntax-source x)))))
  fully-expanded? : boolean? = #f
  namespace : (or/c #f namespace?) = #f

This procedure provides a simplified interface to the rest of the library, as shown in the example below. The list it returns has one vector for each call that would be made to the object in current-annotations. Each vector’s first element is a symbol naming a method in syncheck-annotations<%> and the other elements of the vector are the arguments passed to the method. (Note that this procedure does not account for the callback procedures present in syncheck:add-arrow/name-dup/pxpy.)

The file-or-stx argument gives the input program and fully-expanded? indicates if the file-or-stx argument has already been fully expanded (it is ignored if file-or-stx is not syntax). The namespace argument is installed as the current-namespace or, if namespace is #f, then a new namespace is created, using (make-base-namespace).

See annotations-mixin for some example code to use the other parts of this library.

Note that the paths in the example below have been replaced via make-paths-be-module-paths in order to make the results be platform independent.

> (define (make-paths-be-module-paths x)
    (let loop ([x x])
      (cond
        [(pair? x) (cons (loop (car x)) (loop (cdr x)))]
        [(vector? x) (for/vector ([x (in-vector x)])
                       (loop x))]
        [(path? x) (path->relative-string/library x)]
        [else x])))
> (let ([example-module
         '(module m racket (λ (x) x))])
    (make-paths-be-module-paths
     (show-content
      (read-syntax
       (build-path (current-directory) "dummy-file.rkt")
       (open-input-string (format "~s" example-module))))))
'(#(syncheck:add-require-open-menu 10 16 "<collects>/racket/main.rkt")
  #(syncheck:add-tail-arrow 17 25)
  #(syncheck:add-arrow/name-dup/pxpy
    22
    23
    0.5
    0.5
    25
    26
    0.5
    0.5
    #t
    0
    #f
    #<procedure:name-dup?>)
  #(syncheck:add-text-type 19 20 document-identifier)
  #(syncheck:add-docs-menu
    19
    20
    λ
    "View documentation for “λ” from racket/base, racket"
    "<pkgs>/racket-doc/scribblings/reference/doc/reference/lambda.html"
    (form ((lib "racket/private/base.rkt") λ))
    "(form._((lib._racket/private/base..rkt)._~ce~bb))")
  #(syncheck:add-jump-to-definition
    19
    20
    new-λ
    "<collects>/racket/private/kw.rkt"
    ())
  #(syncheck:add-mouse-over-status 19 20 "imported from racket")
  #(syncheck:add-arrow/name-dup/pxpy
    10
    16
    0.5
    0.5
    19
    20
    0.5
    0.5
    #t
    0
    module-lang
    #<procedure:name-dup?>)
  #(syncheck:add-text-type 19 20 document-identifier)
  #(syncheck:add-docs-menu
    19
    20
    λ
    "View documentation for “λ” from racket/base, racket"
    "<pkgs>/racket-doc/scribblings/reference/doc/reference/lambda.html"
    (form ((lib "racket/private/base.rkt") λ))
    "(form._((lib._racket/private/base..rkt)._~ce~bb))")
  #(syncheck:add-jump-to-definition
    19
    20
    new-λ
    "<collects>/racket/private/kw.rkt"
    ())
  #(syncheck:add-mouse-over-status 19 20 "imported from racket")
  #(syncheck:add-arrow/name-dup/pxpy
    10
    16
    0.5
    0.5
    19
    20
    0.5
    0.5
    #t
    0
    module-lang
    #<procedure:name-dup?>)
  #(syncheck:add-text-type 1 7 document-identifier)
  #(syncheck:add-docs-menu
    1
    7
    module
    "View documentation for “module” from racket/base, racket"
    "<pkgs>/racket-doc/scribblings/reference/doc/reference/module.html"
    (form ('#%kernel module))
    "(form._((quote._~23~25kernel)._module))")
  #(syncheck:add-mouse-over-status 22 23 "1 bound occurrence")
  #(syncheck:add-mouse-over-status 10 16 "1 bound occurrence"))

Changed in version 1.2 of package drracket-tool-lib: Added the #:fully-expanded and #:namespace arguments.

procedure
(make-traversal namespace path) →
(->* (syntax?)
     ((-> any/c void?))
     void?)
(-> void?)
  namespace : namespace?
  path : (or/c #f path-string?)

This function creates some local state about a traversal of syntax objects and returns two functions. The first one should be called with each of the (fully expanded) syntax objects that make up a program (there will be only one if the program is a module) and then the second one should be called to indicate there are no more.

The optional argument to the first function is ignored. It is left there for historical reasons. In the past it was called for each sequence of binding identifiers encountered in define-values, define-syntaxes, and define-values-for-syntax.

During the dynamic extent of the call to the two result functions, the value of the current-annotations parameter is consulted and various methods are invoked in the corresponding object (if any), to indicate what has been found in the syntax object. These methods will only be called if the syntax objects have source locations.

The path argument indicates a directory whose traversal should operate on. When path is #f, it defaults to (current-directory). Otherwise, the path is simplified via simple-form-path before it’s used.

parameter
(current-annotations)
→ (or/c #f (is-a?/c syncheck-annotations<%>))
(current-annotations ca) → void?
ca : (or/c #f (is-a?/c syncheck-annotations<%>))

The methods of the value of this parameter are invoked by the functions returned from make-traversal.

parameter
(current-max-to-send-at-once)
→ (or/c +inf.0 (and/c exact-integer? (>=/c 2)))
(current-max-to-send-at-once m) → void?
m : (or/c +inf.0 (and/c exact-integer? (>=/c 2)))

No longer used.

interface
syncheck-annotations<%> : interface?

Classes implementing this interface are acceptors of information about a traversal of syntax objects. See make-traversal.

Do not implement this interface directly, as it is liable to change without warning. Instead, use the annotations-mixin and override the methods you’re interested in. The annotations-mixin will keep in sync with this interface, providing methods that ignore their arguments.

method
(send a-syncheck-annotations syncheck:find-source-object stx)
→ (or/c #f (not/c #f))
  stx : syntax?
This should return #f if the source of this syntax object is uninteresting for annotations (if, for example, the only interesting annotations are those in the original file and this is a syntax object introduced by a macro and thus has a source location from some other file).
Otherwise, it should return some (non-#f) value that will then be passed to one of the other methods below as a source-obj argument.
method
(send a-syncheck-annotations syncheck:add-text-type
source-obj
start
end
text-type)
→ void?
  source-obj : (not/c #f)
  start : exact-nonnegative-integer?
  end : exact-nonnegative-integer?
   text-type :
(or/c 'matching-identifiers
      'unused-identifier
      'document-identifier)
Called to indicate that the color associated with the text type text-type should be drawn on the background of the given range in the editor, when the mouse moves over it.
This method is usually called by Check Syntax to add background colors to an identifier based on its lexical information. The types 'matching-identifiers, 'unused-identifier and 'document-identifier correspond to the color 'drracket:syncheck:matching-identifiers, 'drracket:syncheck:unused-identifier and 'drracket:syncheck:document-identifier in color scheme specifications, respectively. See Color Schemes.
Added in version 1.8 of package drracket-tool-lib.
method
(send a-syncheck-annotations syncheck:add-background-color
source-obj
start
end
color)
→ void?
  source-obj : (not/c #f)
  start : exact-nonnegative-integer?
  end : exact-nonnegative-integer?
  color : string?
Called to indicate that the color color should be drawn on the background of the given range in the editor, when the mouse moves over it.
This method is not directly called by Check Syntax anymore. Instead see syncheck:add-text-type.
method
(send a-syncheck-annotations syncheck:add-require-open-menu
source-obj
start
end
file)
→ void?
  source-obj : (not/c #f)
  start : exact-nonnegative-integer?
  end : exact-nonnegative-integer?
  file : path-string?
Called to indicate that there is a require at the location from start to end, and that it corresponds to file.
The start and end coordinates typically come from a syntax object in the file that was processed (although they can be completely synthesized by macros in some situations). The start coordinate is one less than that syntax object’s syntax-position field, and the end is the start plus that syntax-object’s syntax-span field. Thus, it is always the case that (<= start end) is true. In some situations, it may be that start can equal end.
Check Syntax adds a popup menu.
method
(send a-syncheck-annotations syncheck:add-docs-menu
source-obj
start
end
id
label
definition-tag
path
tag)
→ void?
  source-obj : (not/c #f)
  start : exact-nonnegative-integer?
  end : exact-nonnegative-integer?
  id : symbol?
  label : any/c
  definition-tag : definition-tag?
  path : any/c
  tag : any/c
Called to indicate that there is something that has documentation between the range start and end. The documented identifier’s name is given by id and the docs are found in the html file path at the html tag tag. The definition-tag argument matches the documented definition. The label argument describes the binding for use in the menu item (although it may be longer than 200 characters).
See syncheck:add-require-open-menu for information about the coordinates start and end.
method
(send a-syncheck-annotations syncheck:add-id-set
all-ids
new-name-interferes?)
→ void?
   all-ids :
(listof (list/c (not/c #f)
                exact-nonnegative-integer?
                exact-nonnegative-integer?))
  new-name-interferes? : (-> symbol boolean?)
This method is no longer called by Check Syntax. It is here for backwards compatibility only. The information it provided must now be synthesized from the information supplied to syncheck:add-arrow/name-dup/pxpy.
method
(send a-syncheck-annotations syncheck:add-arrow
start-source-obj
start-left
start-right
end-source-obj
end-left
end-right
actual?
phase-level)
→ void?
  start-source-obj : (not/c #f)
  start-left : exact-nonnegative-integer?
  start-right : exact-nonnegative-integer?
  end-source-obj : (not/c #f)
  end-left : exact-nonnegative-integer?
  end-right : exact-nonnegative-integer?
  actual? : boolean?
  phase-level : (or/c exact-nonnegative-integer? #f)
This function is not called directly anymore by Check Syntax. Instead syncheck:add-arrow/name-dup/pxpy is.
This method is invoked by the default implementation of syncheck:add-arrow/name-dup in annotations-mixin.
See syncheck:add-require-open-menu for information about the coordinates; start-left and start-right are a pair like syncheck:add-require-open-menu’s start and end, as are end-left and end-right.
method
(send a-syncheck-annotations syncheck:add-arrow/name-dup
start-source-obj
start-left
start-right
end-source-obj
end-left
end-right
actual?
phase-level
require-arrow?
name-dup?)
→ void?
  start-source-obj : (not/c #f)
  start-left : exact-nonnegative-integer?
  start-right : exact-nonnegative-integer?
  end-source-obj : (not/c #f)
  end-left : exact-nonnegative-integer?
  end-right : exact-nonnegative-integer?
  actual? : boolean?
  phase-level : (or/c exact-nonnegative-integer? #f)
  require-arrow? : boolean?
  name-dup? : (-> string? boolean?)
This function is not called directly anymore by Check Syntax. Instead syncheck:add-arrow/name-dup/pxpy is.
The default implementation of syncheck:add-arrow/name-dup/pxpy discards the start-px start-py end-px end-py arguments and calls this method.
See syncheck:add-require-open-menu for information about the coordinates; start-left and start-right are a pair like syncheck:add-require-open-menu’s start and end, as are end-left and end-right.
method
(send a-syncheck-annotations syncheck:add-arrow/name-dup/pxpy
start-source-obj
start-left
start-right
start-px
start-py
end-source-obj
end-left
end-right
end-px
end-py
actual?
phase-level
require-arrow
name-dup?)
→ void?
  start-source-obj : (not/c #f)
  start-left : exact-nonnegative-integer?
  start-right : exact-nonnegative-integer?
  start-px : (real-in 0 1)
  start-py : (real-in 0 1)
  end-source-obj : (not/c #f)
  end-left : exact-nonnegative-integer?
  end-right : exact-nonnegative-integer?
  end-px : (real-in 0 1)
  end-py : (real-in 0 1)
  actual? : boolean?
  phase-level : (or/c exact-nonnegative-integer? #f)
  require-arrow : (or/c boolean? 'module-lang)
  name-dup? : (-> string? boolean?)
Called to indicate that there should be an arrow between the locations described by the first ten arguments. The start-px and start-py indicate how far along the diagonal between the upper-left coordinate of the editor position start-left and the bottom-right of the editor position start-right to draw the foot of the arrow. The end-px and end-py indicate the same things for the head of the arrow.
The phase-level argument indicates the phase of the binding and the actual? argument indicates if the binding is a real one, or a predicted one from a syntax template (predicted bindings are drawn with question marks in Check Syntax).
The require-arrow argument indicates if this arrow points from an imported identifier to its corresponding require. Any true value means that it points to an import via require; #t means it was a normal require and 'module-lang means it comes from the implicit require that a module language provides.
The name-dup? predicate returns #t in case that this variable (either the start or end), when replaced with the given string, would shadow some other binding (or otherwise interfere with the binding structure of the program at the time the program was expanded).
See syncheck:add-require-open-menu for information about the coordinates; start-left and start-right are a pair like syncheck:add-require-open-menu’s start and end, as are end-left and end-right.
Changed in version 1.1 of package drracket-tool-lib: Changed require-arrow to sometimes be 'module-lang.
method
(send a-syncheck-annotations syncheck:add-tail-arrow
from-source-obj
from-pos
to-source-obj
to-pos)
→ void?
  from-source-obj : (not/c #f)
  from-pos : exact-nonnegative-integer?
  to-source-obj : (not/c #f)
  to-pos : exact-nonnegative-integer?
Called to indicate that there are two expressions, beginning at from-pos and to-pos that are in tail position with respect to each other.
method
(send a-syncheck-annotations syncheck:add-mouse-over-status
source-obj
start
end
str)
→ void?
  source-obj : (not/c #f)
  start : exact-nonnegative-integer?
  end : exact-nonnegative-integer?
  str : string?
Called to indicate that the message in str should be shown when the mouse passes over a position in the given range between start and end.
See syncheck:add-require-open-menu for information about the coordinates start and end.
method
(send a-syncheck-annotations syncheck:add-prefixed-require-reference
req-src
req-pos-left
req-pos-right
prefix
prefix-src
prefix-left
prefix-right)
→ void?
  req-src : (not/c #f)
  req-pos-left : exact-nonnegative-integer?
  req-pos-right : exact-nonnegative-integer?
  prefix : symbol?
  prefix-src : any/c
  prefix-left : (or/c #f exact-nonnegative-integer?)
  prefix-right : (or/c #f exact-nonnegative-integer?)
This method is called for each require in the program that has a prefix or prefix-all-except around it in fully expanded form (i.e., it seems to come from a prefix-in or a similar form).
The method is passed the location of the require in the original program, as well as the prefix (as a symbol) and the source locations of the prefix (if they are available).
See syncheck:add-require-open-menu for information about the coordinates; req-pos-left and req-pos-right are a pair like syncheck:add-require-open-menu’s start and end, as are prefix-left and prefix-right.
method
(send a-syncheck-annotations syncheck:add-unused-require
req-src
start
end)
→ void?
  req-src : (not/c #f)
  start : exact-nonnegative-integer?
  end : exact-nonnegative-integer?
This method is called for each require that Check Syntax determines to be unused. The method is passed the location of the name of the required module in the original program.
See syncheck:add-require-open-menu for information about the coordinates start and end.
method
(send a-syncheck-annotations syncheck:add-jump-to-definition
source-obj
start
end
id
filename
submods)
→ void?
  source-obj : (not/c #f)
  start : exact-nonnegative-integer?
  end : exact-nonnegative-integer?
  id : any/c
  filename : path-string?
  submods : (listof symbol?)
Called to indicate that there is some identifier at the given location (named id) that is defined in the submods of the file filename (where an empty list in submods means that the identifier is defined at the top-level module).
See syncheck:add-require-open-menu for information about the coordinates start and end.
method
(send a-syncheck-annotations syncheck:add-definition-target
source-obj
start
finish
id
mods)
→ void?
  source-obj : (not/c #f)
  start : exact-nonnegative-integer?
  finish : exact-nonnegative-integer?
  id : symbol?
  mods : (listof symbol?)
Called to indicate a top-level definition at the location spanned by start and finish. The id argument is the name of the defined variable and the mods are the submodules enclosing the definition, which will be empty if the definition is in the top-level module.
See syncheck:add-require-open-menu for information about the coordinates start and end.
method
(send a-syncheck-annotations syncheck:color-range source-obj
start
end
style-name
mode)
→ void?
  source-obj : (not/c #f)
  start : exact-nonnegative-integer?
  end : exact-nonnegative-integer?
  style-name : any/c
  mode : any/c
Called to indicate that the given location should be colored according to the style style-name when in mode. The mode either indicates regular check syntax or is used indicate blame for potential contract violations (and still experimental).
See syncheck:add-require-open-menu for information about the coordinates start and end.
method
(send a-syncheck-annotations syncheck:add-rename-menu
id
all-ids
new-name-interferes?)
→ void?
  id : symbol?
   all-ids :
(listof (list/c (not/c #f)
                exact-nonnegative-integer?
                exact-nonnegative-integer?))
  new-name-interferes? : (-> symbol boolean?)
This method is listed only for backwards compatibility. It is not called by Check Syntax anymore.

mixin
annotations-mixin : (class? . -> . class?)

result implements:

syncheck-annotations<%>

Supplies all of the methods in syncheck-annotations<%> with default behavior. Be sure to use this mixin to future-proof your code and then override the methods you’re interested in.

By default:

The syncheck:find-source-object method ignores its arguments and returns #f;
the syncheck:add-arrow/name-dup method drops the require-arrow? and name-dup? arguments and calls syncheck:add-arrow;
the syncheck:add-arrow/name-dup/pxpy method drops the from-px, from-py, to-px, and to-py arguments and calls syncheck:add-arrow/name-dup; and
all of the other methods ignore their arguments and return (void).

Here is an example showing how use this library to extract all of the arrows that Check Syntax would draw from various expressions. One subtle point: arrows are only included when the corresponding identifiers are syntax-original?; the code below manages this by copying the properties from an identifier that is syntax-original? in the call to datum->syntax.

> (define arrows-collector%
    (class (annotations-mixin object%)
      (super-new)
      (define/override (syncheck:find-source-object stx)
        stx)
      (define/override (syncheck:add-arrow/name-dup/pxpy
                        start-source-obj start-left start-right start-px start-py
                        end-source-obj end-left end-right end-px end-py
                        actual? phase-level require-arrow? name-dup?)
        (set! arrows
              (cons (list start-source-obj end-source-obj)
                    arrows)))
      (define arrows '())
      (define/public (get-collected-arrows) arrows)))
> (define (arrows form)
    (define base-namespace (make-base-namespace))
    (define-values (add-syntax done)
      (make-traversal base-namespace #f))
    (define collector (new arrows-collector%))
    (parameterize ([current-annotations collector]
                   [current-namespace base-namespace])
      (add-syntax (expand form))
      (done))
    (send collector get-collected-arrows))
> (define (make-id name pos orig?)
    (datum->syntax
     #f
     name
     (list #f #f #f pos (string-length (symbol->string name)))
     (and orig? #'is-orig)))
> (arrows `(λ (,(make-id 'x 1 #t)) ,(make-id 'x 2 #t)))
'((#<syntax x> #<syntax x>))
> (arrows `(λ (x) x))
'()
> (arrows `(λ (,(make-id 'x 1 #f)) ,(make-id 'x 2 #t)))
'()
> (arrows `(λ (,(make-id 'x 1 #t)) x))
'()

syntax
syncheck:find-source-object

Bound to an identifier created with define-local-member-name that is used as the syncheck:find-source-object method of syncheck-annotations<%>.

syntax
syncheck:add-text-type

Bound to an identifier created with define-local-member-name that is used as the syncheck:add-text-type method of syncheck-annotations<%>.

syntax
syncheck:add-background-color

Bound to an identifier created with define-local-member-name that is used as the syncheck:add-background-color method of syncheck-annotations<%>.

syntax
syncheck:add-require-open-menu

Bound to an identifier created with define-local-member-name that is used as the syncheck:add-require-open-menu method of syncheck-annotations<%>.

syntax
syncheck:add-docs-menu

Bound to an identifier created with define-local-member-name that is used as the syncheck:add-docs-menu method of syncheck-annotations<%>.

syntax
syncheck:add-rename-menu

Bound to an identifier created with define-local-member-name that is used as the syncheck:add-rename-menu method of syncheck-annotations<%>.

syntax
syncheck:add-arrow

Bound to an identifier created with define-local-member-name that is used as the syncheck:add-arrow method of syncheck-annotations<%>.

syntax
syncheck:add-arrow/name-dup

Bound to an identifier created with define-local-member-name that is used as the syncheck:add-arrow/name-dup method of syncheck-annotations<%>.

syntax
syncheck:add-arrow/name-dup/pxpy

Bound to an identifier created with define-local-member-name that is used as the syncheck:add-arrow/name-dup/pxpy method of syncheck-annotations<%>.

syntax
syncheck:add-tail-arrow

Bound to an identifier created with define-local-member-name that is used as the syncheck:add-tail-arrow method of syncheck-annotations<%>.

syntax
syncheck:add-mouse-over-status

Bound to an identifier created with define-local-member-name that is used as the syncheck:add-mouse-over-status method of syncheck-annotations<%>.

syntax
syncheck:add-jump-to-definition

Bound to an identifier created with define-local-member-name that is used as the syncheck:add-jump-to-definition method of syncheck-annotations<%>.

syntax
syncheck:add-id-set

Bound to an identifier created with define-local-member-name that is used as the syncheck:add-id-set method of syncheck-annotations<%>.

syntax
syncheck:color-range

Bound to an identifier created with define-local-member-name that is used as the syncheck:color-range method of syncheck-annotations<%>.

syntax
syncheck:add-prefixed-require-reference

Bound to an identifier created with define-local-member-name that is used as the syncheck:add-prefixed-require-reference method of syncheck-annotations<%>.

syntax
syncheck:add-unused-require

Bound to an identifier created with define-local-member-name that is used as the syncheck:add-unused-require method of syncheck-annotations<%>.

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