Cabal consideres lines to be part of a layout block if they are indented
at least one space more than the field line the block belongs to.
Previously Guix considered lines to be a part of the block if they were
indented at least as much as the first line in it.
This also makes a workaround that enabled if statements to have multiple
elses redundant and removes it.
* guix/import/cabal.scm (current-indentation*): Renamed from
current-indentation.
(previous-indentation, current-indentation): New variables.
(make-cabal-parser): Remove outdated comment.
[open]: Use previous-indentation + 1 instead of
current-indentation.
[elif-else]: Split to elif and else to allow only one ELSE in an if
statement.
(read-cabal)[parameterize]: Use current-indentation* and previous-indentation.
* tests/hackage.scm (hackage->guix-package test mixed layout): Expect to
pass.
Change-Id: I3a1495b1588a022fabbfe8dad9f3231e578af4f3
---
guix/import/cabal.scm | 42 +++++++++++++++++++-----------------------
tests/hackage.scm | 2 --
2 files changed, 19 insertions(+), 25 deletions(-)
Toggle diff (91 lines)
diff --git a/guix/import/cabal.scm b/guix/import/cabal.scm
index fe03c30254..b969197455 100644
--- a/guix/import/cabal.scm
+++ b/guix/import/cabal.scm
@@ -130,8 +130,17 @@ (define (context-stack-pop!) ((context-stack) 'pop!))
(define (context-stack-clear!) ((context-stack) 'clear!))
-;; Indentation of the line being parsed.
-(define current-indentation (make-parameter 0))
+;; Indentation of the line being parsed and that of the previous line.
+(define current-indentation* (make-parameter 0))
+
+(define previous-indentation (make-parameter 0))
+
+(define* (current-indentation #:optional value)
+ (if value
+ (begin
+ (previous-indentation (current-indentation*))
+ (current-indentation* value))
+ (current-indentation*)))
;; Signal to reprocess the beginning of line, in case we need to close more
;; than one indentation level.
@@ -196,27 +205,13 @@ (define (make-cabal-parser)
(exprs elif-else) : (append $1 (list ($2 '(()))))
(elif-else) : (list ($1 '(()))))
;; LALR(1) parsers prefer to be left-recursive, which make if-statements slightly involved.
- ;; XXX: This technically allows multiple else statements.
- (elif-else (elif-else ELIF tests OCURLY exprs CCURLY) : (lambda (y) ($1 (list (append (list 'if $3 $5) y))))
- (elif-else ELIF tests open exprs close) : (lambda (y) ($1 (list (append (list 'if $3 $5) y))))
- (elif-else ELSE OCURLY exprs CCURLY) : (lambda (y) ($1 (list $4)))
- ;; The 'open' token after 'tests' is shifted after an 'exprs'
- ;; is found. This is because, instead of 'exprs' a 'OCURLY'
- ;; token is a valid alternative. For this reason, 'open'
- ;; pushes a <parse-context> with a line indentation equal to
- ;; the indentation of 'exprs'.
- ;;
- ;; Differently from this, without the rule above this
- ;; comment, when an 'ELSE' token is found, the 'open' token
- ;; following the 'ELSE' would be shifted immediately, before
- ;; the 'exprs' is found (because there are no other valid
- ;; tokens). The 'open' would therefore create a
- ;; <parse-context> with the indentation of 'ELSE' and not
- ;; 'exprs', creating an inconsistency. We therefore allow
- ;; mixed style conditionals.
- (elif-else ELSE open exprs close) : (lambda (y) ($1 (list $4)))
+ (elif (elif ELIF tests OCURLY exprs CCURLY) : (lambda (y) ($1 (list (append (list 'if $3 $5) y))))
+ (elif ELIF tests open exprs close) : (lambda (y) ($1 (list (append (list 'if $3 $5) y))))
;; Terminating rule.
(if-then) : (lambda (y) (append $1 y)))
+ (elif-else (elif ELSE OCURLY exprs CCURLY) : (lambda (y) ($1 (list $4)))
+ (elif ELSE open exprs close) : (lambda (y) ($1 (list $4)))
+ (elif) : $1)
(if-then (IF tests OCURLY exprs CCURLY) : (list 'if $2 $4)
(IF tests open exprs close) : (list 'if $2 $4))
(tests (TEST OPAREN ID CPAREN) : `(,$1 ,$3)
@@ -237,7 +232,7 @@ (define (make-cabal-parser)
(OPAREN tests CPAREN) : $2)
(open () : (context-stack-push!
(make-parse-context (context layout)
- (current-indentation))))
+ (+ 1 (previous-indentation)))))
(close (VCCURLY))))
(define (peek-next-line-indent port)
@@ -655,7 +650,8 @@ (define* (read-cabal #:optional (port (current-input-port))
(let ((cabal-parser (make-cabal-parser)))
(parameterize ((cabal-file-name
(or file-name (port-filename port) "standard input"))
- (current-indentation 0)
+ (current-indentation* 0)
+ (previous-indentation 0)
(check-bol? #f)
(context-stack (make-stack)))
(cabal-parser (make-lexer port) (errorp)))))
diff --git a/tests/hackage.scm b/tests/hackage.scm
index 8eea818ebd..32e5f39329 100644
--- a/tests/hackage.scm
+++ b/tests/hackage.scm
@@ -306,8 +306,6 @@ (define test-cabal-mixed-layout
ghc-options: -Wall
")
-;; Fails: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=35743
-(test-expect-fail 1)
(test-assert "hackage->guix-package test mixed layout"
(eval-test-with-cabal test-cabal-mixed-layout match-ghc-foo))
--
2.41.0
