diff options
Diffstat (limited to 'guix/scripts')
| -rw-r--r-- | guix/scripts/style.scm | 270 |
1 files changed, 221 insertions, 49 deletions
diff --git a/guix/scripts/style.scm b/guix/scripts/style.scm index 3b246e9c66..a5204d02ef 100644 --- a/guix/scripts/style.scm +++ b/guix/scripts/style.scm @@ -40,11 +40,15 @@ #:use-module (ice-9 control) #:use-module (ice-9 match) #:use-module (ice-9 rdelim) + #:use-module (ice-9 vlist) #:use-module (srfi srfi-1) #:use-module (srfi srfi-9) #:use-module (srfi srfi-26) #:use-module (srfi srfi-37) - #:export (guix-style)) + #:export (pretty-print-with-comments + read-with-comments + + guix-style)) ;;; @@ -109,15 +113,136 @@ ;;; Comment-preserving pretty-printer. ;;; +(define-syntax vhashq + (syntax-rules () + ((_) vlist-null) + ((_ (key value) 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. + (vhashq + ('begin 1) + ('lambda 2) + ('lambda* 2) + ('match-lambda 1) + ('match-lambda* 2) + ('define 2) + ('define* 2) + ('define-public 2) + ('define*-public 2) + ('define-syntax 2) + ('define-syntax-rule 2) + ('define-module 2) + ('define-gexp-compiler 2) + ('let 2) + ('let* 2) + ('letrec 2) + ('letrec* 2) + ('match 2) + ('when 2) + ('unless 2) + ('package 1) + ('origin 1) + ('operating-system 1) + ('modify-inputs 2) + ('modify-phases 2) + ('add-after 3) + ('add-before 3) + ;; ('replace 2) + ('substitute* 2) + ('substitute-keyword-arguments 2) + ('call-with-input-file 2) + ('call-with-output-file 2) + ('with-output-to-file 2) + ('with-input-from-file 2))) + +(define (special-form? symbol) + (vhash-assq symbol %special-forms)) + +(define (escaped-string str) + "Return STR with backslashes and double quotes escaped. Everything else, in +particular newlines, is left as is." + (list->string + `(#\" + ,@(string-fold-right (lambda (chr lst) + (match chr + (#\" (cons* #\\ #\" lst)) + (#\\ (cons* #\\ #\\ lst)) + (_ (cons chr lst)))) + '() + str) + #\"))) + +(define (string-width str) + "Return the \"width\" of STR--i.e., the width of the longest line of STR." + (apply max (map string-length (string-split str #\newline)))) + (define* (pretty-print-with-comments port obj #:key (indent 0) (max-width 78) (long-list 5)) + "Pretty-print OBJ to PORT, attempting to at most MAX-WIDTH character columns +and assuming the current column is INDENT. Comments present in OBJ are +included in the output. + +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 (obj obj)) + (define (print-sequence indent column lst delimited?) + (define long? + (> (length lst) long-list)) + + (let print ((lst lst) + (first? #t) + (delimited? delimited?) + (column column)) + (match lst + (() + column) + ((item . tail) + (define newline? + ;; Insert a newline if ITEM is itself a list, or if TAIL is long, + ;; but only if ITEM is not the first item. Also insert a newline + ;; before a keyword. + (and (or (pair? item) long? + (and (keyword? item) + (not (eq? item #:allow-other-keys)))) + (not first?) (not delimited?) + (not (comment? item)))) + + (when newline? + (newline port) + (display (make-string indent #\space) port)) + (let ((column (if newline? indent column))) + (print tail #f + (comment? item) + (loop indent column + (or newline? delimited?) + item))))))) + + (define (sequence-would-protrude? indent lst) + ;; Return true if elements of LST written at INDENT would protrude + ;; beyond MAX-WIDTH. This is implemented as a cheap test with false + ;; negatives to avoid actually rendering all of LST. + (find (match-lambda + ((? string? str) + (>= (+ (string-width str) 2 indent) max-width)) + ((? symbol? symbol) + (>= (+ (string-width (symbol->string symbol)) indent) + max-width)) + ((? boolean?) + (>= (+ 2 indent) max-width)) + (() + (>= (+ 2 indent) max-width)) + (_ ;don't know + #f)) + lst)) + (match obj ((? comment? comment) (if (comment-margin? comment) @@ -145,57 +270,104 @@ (unless delimited? (display " " port)) (display "," port) (loop indent (+ column (if delimited? 1 2)) #t lst)) - (('modify-inputs inputs clauses ...) - ;; Special-case 'modify-inputs' to have one clause per line and custom - ;; indentation. - (let ((head "(modify-inputs ")) + (('unquote-splicing lst) + (unless delimited? (display " " port)) + (display ",@" port) + (loop indent (+ column (if delimited? 2 3)) #t lst)) + (('gexp lst) + (unless delimited? (display " " port)) + (display "#~" port) + (loop indent (+ column (if delimited? 2 3)) #t lst)) + (('ungexp obj) + (unless delimited? (display " " port)) + (display "#$" port) + (loop indent (+ column (if delimited? 2 3)) #t obj)) + (('ungexp-native obj) + (unless delimited? (display " " port)) + (display "#+" port) + (loop indent (+ column (if delimited? 2 3)) #t obj)) + (('ungexp-splicing lst) + (unless delimited? (display " " port)) + (display "#$@" port) + (loop indent (+ column (if delimited? 3 4)) #t lst)) + (('ungexp-native-splicing lst) + (unless delimited? (display " " port)) + (display "#+@" port) + (loop indent (+ column (if delimited? 3 4)) #t 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))) + (unless delimited? (display " " port)) + (display "(" port) (display head port) - (loop (+ indent 4) - (+ column (string-length head)) - #t - inputs) - (let* ((indent (+ indent 2)) - (column (fold (lambda (clause column) - (newline port) - (display (make-string indent #\space) - port) - (loop indent indent #t clause)) - indent - clauses))) + (unless (zero? lead) + (display " " port)) + + ;; Print the first LEAD arguments. + (let* ((indent (+ column 2 + (if delimited? 0 1))) + (column (+ column 1 + (if (zero? lead) 0 1) + (if delimited? 0 1) + (string-length head))) + (initial-indent column)) + (define new-column + (let inner ((n lead) + (arguments (take arguments (min lead total))) + (column column)) + (if (zero? n) + (begin + (newline port) + (display (make-string indent #\space) port) + indent) + (match arguments + (() column) + ((head . tail) + (inner (- n 1) tail + (loop initial-indent + column + (= n lead) + head))))))) + + ;; Print the remaining arguments. + (let ((column (print-sequence + indent new-column + (drop arguments (min lead total)) + #t))) + (display ")" port) + (+ column 1))))) + ((head tail ...) + (let* ((overflow? (>= column max-width)) + (column (if overflow? + (+ indent 1) + (+ column (if delimited? 1 2))))) + (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)) + (indent (if (or (>= new-column max-width) + (not (symbol? head)) + (sequence-would-protrude? + (+ new-column 1) tail)) + column + (+ new-column 1)))) + (define column + (print-sequence indent new-column tail #f)) (display ")" port) (+ column 1)))) - ((head tail ...) - (unless delimited? (display " " port)) - (display "(" port) - (let* ((new-column (loop indent (+ 1 column) #t head)) - (indent (+ indent (- new-column column))) - (long? (> (length tail) long-list))) - (define column - (fold2 (lambda (item column first?) - (define newline? - ;; Insert a newline if ITEM is itself a list, or if TAIL - ;; is long, but only if ITEM is not the first item. - (and (or (pair? item) long?) - (not first?) (not (comment? item)))) - - (when newline? - (newline port) - (display (make-string indent #\space) port)) - (let ((column (if newline? indent column))) - (values (loop indent - column - (= column indent) - item) - (comment? item)))) - (+ 1 new-column) - #t ;first - tail)) - (display ")" port) - (+ column 1))) (_ - (let* ((str (object->string obj)) - (len (string-length str))) - (if (> (+ column 1 len) max-width) + (let* ((str (if (string? obj) + (escaped-string obj) + (object->string obj))) + (len (string-width str))) + (if (and (> (+ column 1 len) max-width) + (not delimited?)) (begin (newline port) (display (make-string indent #\space) port) @@ -204,7 +376,7 @@ (begin (unless delimited? (display " " port)) (display str port) - (+ column (if delimited? 1 2) len)))))))) + (+ column (if delimited? 0 1) len)))))))) (define (object->string* obj indent) (call-with-output-string |