From 208a7aa17b101083bd9969fec9ca4e2dca37b3af Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= Date: Mon, 3 Jan 2022 09:05:54 +0100 Subject: [PATCH] style: Allow special forms to be scoped. * guix/scripts/style.scm (vhashq): Add clause for 'lst, and change default clause. (%special-forms): Add context for 'add-after and 'add-before. Add 'replace. (prefix?, special-form-lead): New procedures. (special-form?): Remove. (pretty-print-with-comments): Add 'context' to the threaded state. Adjust 'print-sequence' and adjust 'loop' calls accordingly. * tests/style.scm: Add tests for 'replace. --- guix/scripts/style.scm | 88 +++++++++++++++++++++++++++++------------- tests/style.scm | 12 ++++++ 2 files changed, 73 insertions(+), 27 deletions(-) diff --git a/guix/scripts/style.scm b/guix/scripts/style.scm index a5204d02ef..625e942613 100644 --- a/guix/scripts/style.scm +++ b/guix/scripts/style.scm @@ -114,14 +114,19 @@ ;;; (define-syntax vhashq - (syntax-rules () + (syntax-rules (quote) ((_) vlist-null) + ((_ (key (quote (lst ...))) rest ...) + (vhash-consq key '(lst ...) (vhashq rest ...))) ((_ (key value) rest ...) - (vhash-consq key value (vhashq rest ...))))) + (vhash-consq key '((() . value)) (vhashq rest ...))))) (define %special-forms ;; Forms that are indented specially. The number is meant to be understood - ;; like Emacs' 'scheme-indent-function' symbol property. + ;; like Emacs' 'scheme-indent-function' symbol property. When given an + ;; alist instead of a number, the alist gives "context" in which the symbol + ;; is a special form; for instance, context (modify-phases) means that the + ;; symbol must appear within a (modify-phases ...) expression. (vhashq ('begin 1) ('lambda 2) @@ -148,9 +153,9 @@ ('operating-system 1) ('modify-inputs 2) ('modify-phases 2) - ('add-after 3) - ('add-before 3) - ;; ('replace 2) + ('add-after '(((modify-phases) . 3))) + ('add-before '(((modify-phases) . 3))) + ('replace '(((modify-phases) . 2))) ;different from 'modify-inputs' ('substitute* 2) ('substitute-keyword-arguments 2) ('call-with-input-file 2) @@ -158,8 +163,30 @@ ('with-output-to-file 2) ('with-input-from-file 2))) -(define (special-form? symbol) - (vhash-assq symbol %special-forms)) +(define (prefix? candidate lst) + "Return true if CANDIDATE is a prefix of LST." + (let loop ((candidate candidate) + (lst lst)) + (match candidate + (() #t) + ((head1 . rest1) + (match lst + (() #f) + ((head2 . rest2) + (and (equal? head1 head2) + (loop rest1 rest2)))))))) + +(define (special-form-lead symbol context) + "If SYMBOL is a special form in the given CONTEXT, return its number of +arguments; otherwise return #f. CONTEXT is a stack of symbols lexically +surrounding SYMBOL." + (match (vhash-assq symbol %special-forms) + (#f #f) + ((_ . alist) + (any (match-lambda + ((prefix . level) + (and (prefix? prefix context) (- level 1)))) + alist)))) (define (escaped-string str) "Return STR with backslashes and double quotes escaped. Everything else, in @@ -192,8 +219,9 @@ Lists longer than LONG-LIST are written as one element per line." (let loop ((indent indent) (column indent) (delimited? #t) ;true if comes after a delimiter + (context '()) ;list of "parent" symbols (obj obj)) - (define (print-sequence indent column lst delimited?) + (define (print-sequence context indent column lst delimited?) (define long? (> (length lst) long-list)) @@ -223,6 +251,7 @@ Lists longer than LONG-LIST are written as one element per line." (comment? item) (loop indent column (or newline? delimited?) + context item))))))) (define (sequence-would-protrude? indent lst) @@ -243,6 +272,9 @@ Lists longer than LONG-LIST are written as one element per line." #f)) lst)) + (define (special-form? head) + (special-form-lead head context)) + (match obj ((? comment? comment) (if (comment-margin? comment) @@ -261,45 +293,46 @@ Lists longer than LONG-LIST are written as one element per line." (('quote lst) (unless delimited? (display " " port)) (display "'" port) - (loop indent (+ column (if delimited? 1 2)) #t lst)) + (loop indent (+ column (if delimited? 1 2)) #t context lst)) (('quasiquote lst) (unless delimited? (display " " port)) (display "`" port) - (loop indent (+ column (if delimited? 1 2)) #t lst)) + (loop indent (+ column (if delimited? 1 2)) #t context lst)) (('unquote lst) (unless delimited? (display " " port)) (display "," port) - (loop indent (+ column (if delimited? 1 2)) #t lst)) + (loop indent (+ column (if delimited? 1 2)) #t context lst)) (('unquote-splicing lst) (unless delimited? (display " " port)) (display ",@" port) - (loop indent (+ column (if delimited? 2 3)) #t lst)) + (loop indent (+ column (if delimited? 2 3)) #t context lst)) (('gexp lst) (unless delimited? (display " " port)) (display "#~" port) - (loop indent (+ column (if delimited? 2 3)) #t lst)) + (loop indent (+ column (if delimited? 2 3)) #t context lst)) (('ungexp obj) (unless delimited? (display " " port)) (display "#$" port) - (loop indent (+ column (if delimited? 2 3)) #t obj)) + (loop indent (+ column (if delimited? 2 3)) #t context obj)) (('ungexp-native obj) (unless delimited? (display " " port)) (display "#+" port) - (loop indent (+ column (if delimited? 2 3)) #t obj)) + (loop indent (+ column (if delimited? 2 3)) #t context obj)) (('ungexp-splicing lst) (unless delimited? (display " " port)) (display "#$@" port) - (loop indent (+ column (if delimited? 3 4)) #t lst)) + (loop indent (+ column (if delimited? 3 4)) #t context lst)) (('ungexp-native-splicing lst) (unless delimited? (display " " port)) (display "#+@" port) - (loop indent (+ column (if delimited? 3 4)) #t lst)) + (loop indent (+ column (if delimited? 3 4)) #t context lst)) (((? special-form? head) arguments ...) ;; Special-case 'let', 'lambda', 'modify-inputs', etc. so the second ;; and following arguments are less indented. - (let* ((lead (- (cdr (vhash-assq head %special-forms)) 1)) - (head (symbol->string head)) - (total (length arguments))) + (let* ((lead (special-form-lead head context)) + (context (cons head context)) + (head (symbol->string head)) + (total (length arguments))) (unless delimited? (display " " port)) (display "(" port) (display head port) @@ -327,14 +360,14 @@ Lists longer than LONG-LIST are written as one element per line." (() column) ((head . tail) (inner (- n 1) tail - (loop initial-indent - column + (loop initial-indent column (= n lead) + context head))))))) ;; Print the remaining arguments. (let ((column (print-sequence - indent new-column + context indent new-column (drop arguments (min lead total)) #t))) (display ")" port) @@ -343,14 +376,15 @@ Lists longer than LONG-LIST are written as one element per line." (let* ((overflow? (>= column max-width)) (column (if overflow? (+ indent 1) - (+ column (if delimited? 1 2))))) + (+ column (if delimited? 1 2)))) + (context (cons head context))) (if overflow? (begin (newline port) (display (make-string indent #\space) port)) (unless delimited? (display " " port))) (display "(" port) - (let* ((new-column (loop column column #t head)) + (let* ((new-column (loop column column #t context head)) (indent (if (or (>= new-column max-width) (not (symbol? head)) (sequence-would-protrude? @@ -358,7 +392,7 @@ Lists longer than LONG-LIST are written as one element per line." column (+ new-column 1)))) (define column - (print-sequence indent new-column tail #f)) + (print-sequence context indent new-column tail #f)) (display ")" port) (+ column 1)))) (_ diff --git a/tests/style.scm b/tests/style.scm index d9e8d803f4..6c449cb72e 100644 --- a/tests/style.scm +++ b/tests/style.scm @@ -453,6 +453,18 @@ mnopqrstuvwxyz.\")" \"abcdefghijklmnopqrstuvwxyz\")" #:max-width 33) +(test-pretty-print "\ +(modify-phases %standard-phases + (replace 'build + ;; Nicely indented in 'modify-phases' context. + (lambda _ + #t)))") + +(test-pretty-print "\ +(modify-inputs inputs + ;; Regular indentation for 'replace' here. + (replace \"gmp\" gmp))") + (test-end) ;; Local Variables: