de5cbd4a38
Previously, 'display-error' (as used by 'warn-about-load-error', for instance) would be called with a wrong number of arguments when a 'record-abi-mismatch-error' was caught: warning: failed to load '(gnu tests install)': Backtrace: [...] ERROR: In procedure display-error: Wrong number of arguments to #<procedure display-error (_ _ _ _ _ _)> Now you get warnings and error reports as intended: warning: failed to load '(gnu tests install)': In procedure abi-check: <openssh-configuration>: record ABI mismatch; recompilation needed warning: failed to load '(gnu tests ssh)': In procedure abi-check: <openssh-configuration>: record ABI mismatch; recompilation needed * guix/records.scm (print-record-abi-mismatch-error): Remove. Remove top-level call to 'set-exception-printer!'. (abi-check): Use arguments as expected by 'display-error'.
439 lines
18 KiB
Scheme
439 lines
18 KiB
Scheme
;;; GNU Guix --- Functional package management for GNU
|
|
;;; Copyright © 2012, 2013, 2014, 2015, 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
|
|
;;;
|
|
;;; This file is part of GNU Guix.
|
|
;;;
|
|
;;; GNU Guix is free software; you can redistribute it and/or modify it
|
|
;;; under the terms of the GNU General Public License as published by
|
|
;;; the Free Software Foundation; either version 3 of the License, or (at
|
|
;;; your option) any later version.
|
|
;;;
|
|
;;; GNU Guix is distributed in the hope that it will be useful, but
|
|
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
;;; GNU General Public License for more details.
|
|
;;;
|
|
;;; You should have received a copy of the GNU General Public License
|
|
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
(define-module (guix records)
|
|
#:use-module (srfi srfi-1)
|
|
#:use-module (srfi srfi-9)
|
|
#:use-module (srfi srfi-26)
|
|
#:use-module (ice-9 match)
|
|
#:use-module (ice-9 regex)
|
|
#:use-module (ice-9 rdelim)
|
|
#:export (define-record-type*
|
|
alist->record
|
|
object->fields
|
|
recutils->alist
|
|
match-record))
|
|
|
|
;;; Commentary:
|
|
;;;
|
|
;;; Utilities for dealing with Scheme records.
|
|
;;;
|
|
;;; Code:
|
|
|
|
(define-syntax record-error
|
|
(syntax-rules ()
|
|
"Report a syntactic error in use of CONSTRUCTOR."
|
|
((_ constructor form fmt args ...)
|
|
(syntax-violation constructor
|
|
(format #f fmt args ...)
|
|
form))))
|
|
|
|
(define (report-invalid-field-specifier name bindings)
|
|
"Report the first invalid binding among BINDINGS."
|
|
(let loop ((bindings bindings))
|
|
(syntax-case bindings ()
|
|
(((field value) rest ...) ;good
|
|
(loop #'(rest ...)))
|
|
((weird _ ...) ;weird!
|
|
(syntax-violation name "invalid field specifier" #'weird)))))
|
|
|
|
(eval-when (expand load eval)
|
|
;; The procedures below are needed both at run time and at expansion time.
|
|
|
|
(define (current-abi-identifier type)
|
|
"Return an identifier unhygienically derived from TYPE for use as its
|
|
\"current ABI\" variable."
|
|
(let ((type-name (syntax->datum type)))
|
|
(datum->syntax
|
|
type
|
|
(string->symbol
|
|
(string-append "% " (symbol->string type-name)
|
|
" abi-cookie")))))
|
|
|
|
(define (abi-check type cookie)
|
|
"Return syntax that checks that the current \"application binary
|
|
interface\" (ABI) for TYPE is equal to COOKIE."
|
|
(with-syntax ((current-abi (current-abi-identifier type)))
|
|
#`(unless (eq? current-abi #,cookie)
|
|
;; The source file where this exception is thrown must be
|
|
;; recompiled.
|
|
(throw 'record-abi-mismatch-error 'abi-check
|
|
"~a: record ABI mismatch; recompilation needed"
|
|
'(#,type) '())))))
|
|
|
|
(define-syntax make-syntactic-constructor
|
|
(syntax-rules ()
|
|
"Make the syntactic constructor NAME for TYPE, that calls CTOR, and
|
|
expects all of EXPECTED fields to be initialized. DEFAULTS is the list of
|
|
FIELD/DEFAULT-VALUE tuples, THUNKED is the list of identifiers of thunked
|
|
fields, and DELAYED is the list of identifiers of delayed fields.
|
|
|
|
ABI-COOKIE is the cookie (an integer) against which to check the run-time ABI
|
|
of TYPE matches the expansion-time ABI."
|
|
((_ type name ctor (expected ...)
|
|
#:abi-cookie abi-cookie
|
|
#:thunked thunked
|
|
#:delayed delayed
|
|
#:innate innate
|
|
#:defaults defaults)
|
|
(define-syntax name
|
|
(lambda (s)
|
|
(define (record-inheritance orig-record field+value)
|
|
;; Produce code that returns a record identical to ORIG-RECORD,
|
|
;; except that values for the FIELD+VALUE alist prevail.
|
|
(define (field-inherited-value f)
|
|
(and=> (find (lambda (x)
|
|
(eq? f (car (syntax->datum x))))
|
|
field+value)
|
|
car))
|
|
|
|
;; Make sure there are no unknown field names.
|
|
(let* ((fields (map (compose car syntax->datum) field+value))
|
|
(unexpected (lset-difference eq? fields '(expected ...))))
|
|
(when (pair? unexpected)
|
|
(record-error 'name s "extraneous field initializers ~a"
|
|
unexpected)))
|
|
|
|
#`(make-struct/no-tail type
|
|
#,@(map (lambda (field index)
|
|
(or (field-inherited-value field)
|
|
(if (innate-field? field)
|
|
(wrap-field-value
|
|
field (field-default-value field))
|
|
#`(struct-ref #,orig-record
|
|
#,index))))
|
|
'(expected ...)
|
|
(iota (length '(expected ...))))))
|
|
|
|
(define (thunked-field? f)
|
|
(memq (syntax->datum f) 'thunked))
|
|
|
|
(define (delayed-field? f)
|
|
(memq (syntax->datum f) 'delayed))
|
|
|
|
(define (innate-field? f)
|
|
(memq (syntax->datum f) 'innate))
|
|
|
|
(define (wrap-field-value f value)
|
|
(cond ((thunked-field? f)
|
|
#`(lambda () #,value))
|
|
((delayed-field? f)
|
|
#`(delay #,value))
|
|
(else value)))
|
|
|
|
(define default-values
|
|
;; List of symbol/value tuples.
|
|
(map (match-lambda
|
|
((f v)
|
|
(list (syntax->datum f) v)))
|
|
#'defaults))
|
|
|
|
(define (field-default-value f)
|
|
(car (assoc-ref default-values (syntax->datum f))))
|
|
|
|
(define (field-bindings field+value)
|
|
;; Return field to value bindings, for use in 'let*' below.
|
|
(map (lambda (field+value)
|
|
(syntax-case field+value ()
|
|
((field value)
|
|
#`(field
|
|
#,(wrap-field-value #'field #'value)))))
|
|
field+value))
|
|
|
|
(syntax-case s (inherit expected ...)
|
|
((_ (inherit orig-record) (field value) (... ...))
|
|
#`(let* #,(field-bindings #'((field value) (... ...)))
|
|
#,(abi-check #'type abi-cookie)
|
|
#,(record-inheritance #'orig-record
|
|
#'((field value) (... ...)))))
|
|
((_ (field value) (... ...))
|
|
(let ((fields (map syntax->datum #'(field (... ...)))))
|
|
(define (field-value f)
|
|
(or (find (lambda (x)
|
|
(eq? f (syntax->datum x)))
|
|
#'(field (... ...)))
|
|
(wrap-field-value f (field-default-value f))))
|
|
|
|
(let ((fields (append fields (map car default-values))))
|
|
(cond ((lset= eq? fields '(expected ...))
|
|
#`(let* #,(field-bindings
|
|
#'((field value) (... ...)))
|
|
#,(abi-check #'type abi-cookie)
|
|
(ctor #,@(map field-value '(expected ...)))))
|
|
((pair? (lset-difference eq? fields
|
|
'(expected ...)))
|
|
(record-error 'name s
|
|
"extraneous field initializers ~a"
|
|
(lset-difference eq? fields
|
|
'(expected ...))))
|
|
(else
|
|
(record-error 'name s
|
|
"missing field initializers ~a"
|
|
(lset-difference eq?
|
|
'(expected ...)
|
|
fields)))))))
|
|
((_ bindings (... ...))
|
|
;; One of BINDINGS doesn't match the (field value) pattern.
|
|
;; Report precisely which one is faulty, instead of letting the
|
|
;; "source expression failed to match any pattern" error.
|
|
(report-invalid-field-specifier 'name
|
|
#'(bindings (... ...))))))))))
|
|
|
|
(define-syntax-rule (define-field-property-predicate predicate property)
|
|
"Define PREDICATE as a procedure that takes a syntax object and, when passed
|
|
a field specification, returns the field name if it has the given PROPERTY."
|
|
(define (predicate s)
|
|
(syntax-case s (property)
|
|
((field (property values (... ...)) _ (... ...))
|
|
#'field)
|
|
((field _ properties (... ...))
|
|
(predicate #'(field properties (... ...))))
|
|
(_ #f))))
|
|
|
|
(define-syntax define-record-type*
|
|
(lambda (s)
|
|
"Define the given record type such that an additional \"syntactic
|
|
constructor\" is defined, which allows instances to be constructed with named
|
|
field initializers, à la SRFI-35, as well as default values. An example use
|
|
may look like this:
|
|
|
|
(define-record-type* <thing> thing make-thing
|
|
thing?
|
|
(name thing-name (default \"chbouib\"))
|
|
(port thing-port
|
|
(default (current-output-port)) (thunked))
|
|
(loc thing-location (innate) (default (current-source-location))))
|
|
|
|
This example defines a macro 'thing' that can be used to instantiate records
|
|
of this type:
|
|
|
|
(thing
|
|
(name \"foo\")
|
|
(port (current-error-port)))
|
|
|
|
The value of 'name' or 'port' could as well be omitted, in which case the
|
|
default value specified in the 'define-record-type*' form is used:
|
|
|
|
(thing)
|
|
|
|
The 'port' field is \"thunked\", meaning that calls like '(thing-port x)' will
|
|
actually compute the field's value in the current dynamic extent, which is
|
|
useful when referring to fluids in a field's value.
|
|
|
|
A field can also be marked as \"delayed\" instead of \"thunked\", in which
|
|
case its value is effectively wrapped in a (delay …) form.
|
|
|
|
It is possible to copy an object 'x' created with 'thing' like this:
|
|
|
|
(thing (inherit x) (name \"bar\"))
|
|
|
|
This expression returns a new object equal to 'x' except for its 'name'
|
|
field and its 'loc' field---the latter is marked as \"innate\", so it is not
|
|
inherited."
|
|
|
|
(define (field-default-value s)
|
|
(syntax-case s (default)
|
|
((field (default val) _ ...)
|
|
(list #'field #'val))
|
|
((field _ properties ...)
|
|
(field-default-value #'(field properties ...)))
|
|
(_ #f)))
|
|
|
|
(define-field-property-predicate delayed-field? delayed)
|
|
(define-field-property-predicate thunked-field? thunked)
|
|
(define-field-property-predicate innate-field? innate)
|
|
|
|
(define (wrapped-field? s)
|
|
(or (thunked-field? s) (delayed-field? s)))
|
|
|
|
(define (wrapped-field-accessor-name field)
|
|
;; Return the name (an unhygienic syntax object) of the "real"
|
|
;; getter for field, which is assumed to be a wrapped field.
|
|
(syntax-case field ()
|
|
((field get properties ...)
|
|
(let* ((getter (syntax->datum #'get))
|
|
(real-getter (symbol-append '% getter '-real)))
|
|
(datum->syntax #'get real-getter)))))
|
|
|
|
(define (field-spec->srfi-9 field)
|
|
;; Convert a field spec of our style to a SRFI-9 field spec of the
|
|
;; form (field get).
|
|
(syntax-case field ()
|
|
((name get properties ...)
|
|
#`(name
|
|
#,(if (wrapped-field? field)
|
|
(wrapped-field-accessor-name field)
|
|
#'get)))))
|
|
|
|
(define (thunked-field-accessor-definition field)
|
|
;; Return the real accessor for FIELD, which is assumed to be a
|
|
;; thunked field.
|
|
(syntax-case field ()
|
|
((name get _ ...)
|
|
(with-syntax ((real-get (wrapped-field-accessor-name field)))
|
|
#'(define-inlinable (get x)
|
|
;; The real value of that field is a thunk, so call it.
|
|
((real-get x)))))))
|
|
|
|
(define (delayed-field-accessor-definition field)
|
|
;; Return the real accessor for FIELD, which is assumed to be a
|
|
;; delayed field.
|
|
(syntax-case field ()
|
|
((name get _ ...)
|
|
(with-syntax ((real-get (wrapped-field-accessor-name field)))
|
|
#'(define-inlinable (get x)
|
|
;; The real value of that field is a promise, so force it.
|
|
(force (real-get x)))))))
|
|
|
|
(define (compute-abi-cookie field-specs)
|
|
;; Compute an "ABI cookie" for the given FIELD-SPECS. We use
|
|
;; 'string-hash' because that's a better hash function that 'hash' on a
|
|
;; list of symbols.
|
|
(syntax-case field-specs ()
|
|
(((field get properties ...) ...)
|
|
(string-hash (object->string
|
|
(syntax->datum #'((field properties ...) ...)))
|
|
most-positive-fixnum))))
|
|
|
|
(syntax-case s ()
|
|
((_ type syntactic-ctor ctor pred
|
|
(field get properties ...) ...)
|
|
(let* ((field-spec #'((field get properties ...) ...))
|
|
(thunked (filter-map thunked-field? field-spec))
|
|
(delayed (filter-map delayed-field? field-spec))
|
|
(innate (filter-map innate-field? field-spec))
|
|
(defaults (filter-map field-default-value
|
|
#'((field properties ...) ...)))
|
|
(cookie (compute-abi-cookie field-spec)))
|
|
(with-syntax (((field-spec* ...)
|
|
(map field-spec->srfi-9 field-spec))
|
|
((thunked-field-accessor ...)
|
|
(filter-map (lambda (field)
|
|
(and (thunked-field? field)
|
|
(thunked-field-accessor-definition
|
|
field)))
|
|
field-spec))
|
|
((delayed-field-accessor ...)
|
|
(filter-map (lambda (field)
|
|
(and (delayed-field? field)
|
|
(delayed-field-accessor-definition
|
|
field)))
|
|
field-spec)))
|
|
#`(begin
|
|
(define-record-type type
|
|
(ctor field ...)
|
|
pred
|
|
field-spec* ...)
|
|
(define #,(current-abi-identifier #'type)
|
|
#,cookie)
|
|
thunked-field-accessor ...
|
|
delayed-field-accessor ...
|
|
(make-syntactic-constructor type syntactic-ctor ctor
|
|
(field ...)
|
|
#:abi-cookie #,cookie
|
|
#:thunked #,thunked
|
|
#:delayed #,delayed
|
|
#:innate #,innate
|
|
#:defaults #,defaults))))))))
|
|
|
|
(define* (alist->record alist make keys
|
|
#:optional (multiple-value-keys '()))
|
|
"Apply MAKE to the values associated with KEYS in ALIST. Items in KEYS that
|
|
are also in MULTIPLE-VALUE-KEYS are considered to occur possibly multiple
|
|
times in ALIST, and thus their value is a list."
|
|
(let ((args (map (lambda (key)
|
|
(if (member key multiple-value-keys)
|
|
(filter-map (match-lambda
|
|
((k . v)
|
|
(and (equal? k key) v)))
|
|
alist)
|
|
(assoc-ref alist key)))
|
|
keys)))
|
|
(apply make args)))
|
|
|
|
(define (object->fields object fields port)
|
|
"Write OBJECT (typically a record) as a series of recutils-style fields to
|
|
PORT, according to FIELDS. FIELDS must be a list of field name/getter pairs."
|
|
(let loop ((fields fields))
|
|
(match fields
|
|
(()
|
|
object)
|
|
(((field . get) rest ...)
|
|
(format port "~a: ~a~%" field (get object))
|
|
(loop rest)))))
|
|
|
|
(define %recutils-field-charset
|
|
;; Valid characters starting a recutils field.
|
|
;; info "(recutils) Fields"
|
|
(char-set-union char-set:upper-case
|
|
char-set:lower-case
|
|
(char-set #\%)))
|
|
|
|
(define (recutils->alist port)
|
|
"Read a recutils-style record from PORT and return it as a list of key/value
|
|
pairs. Stop upon an empty line (after consuming it) or EOF."
|
|
(let loop ((line (read-line port))
|
|
(result '()))
|
|
(cond ((eof-object? line)
|
|
(reverse result))
|
|
((string-null? line)
|
|
(if (null? result)
|
|
(loop (read-line port) result) ; leading space: ignore it
|
|
(reverse result))) ; end-of-record marker
|
|
(else
|
|
;; Now check the first character of LINE, since that's what the
|
|
;; recutils manual says is enough.
|
|
(let ((first (string-ref line 0)))
|
|
(cond
|
|
((char-set-contains? %recutils-field-charset first)
|
|
(let* ((colon (string-index line #\:))
|
|
(field (string-take line colon))
|
|
(value (string-trim (string-drop line (+ 1 colon)))))
|
|
(loop (read-line port)
|
|
(alist-cons field value result))))
|
|
((eqv? first #\#) ;info "(recutils) Comments"
|
|
(loop (read-line port) result))
|
|
((eqv? first #\+) ;info "(recutils) Fields"
|
|
(let ((new-line (if (string-prefix? "+ " line)
|
|
(string-drop line 2)
|
|
(string-drop line 1))))
|
|
(match result
|
|
(((field . value) rest ...)
|
|
(loop (read-line port)
|
|
`((,field . ,(string-append value "\n" new-line))
|
|
,@rest))))))
|
|
(else
|
|
(error "unmatched line" line))))))))
|
|
|
|
(define-syntax match-record
|
|
(syntax-rules ()
|
|
"Bind each FIELD of a RECORD of the given TYPE to it's FIELD name.
|
|
The current implementation does not support thunked and delayed fields."
|
|
((_ record type (field fields ...) body ...)
|
|
(if (eq? (struct-vtable record) type)
|
|
;; TODO compute indices and report wrong-field-name errors at
|
|
;; expansion time
|
|
;; TODO support thunked and delayed fields
|
|
(let ((field ((record-accessor type 'field) record)))
|
|
(match-record record type (fields ...) body ...))
|
|
(throw 'wrong-type-arg record)))
|
|
((_ record type () body ...)
|
|
(begin body ...))))
|
|
|
|
;;; records.scm ends here
|