From 635394275d8eff363b09b232bb84ec04d3bcf64b Mon Sep 17 00:00:00 2001 From: David Kastrup Date: Thu, 2 Jun 2016 14:07:02 +0200 Subject: [PATCH] Issue 4874/1: Don't overwrite pre-bound session variables This is necessary in order to use session variables in lily-imports.cc --- scm/lily.scm | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) diff --git a/scm/lily.scm b/scm/lily.scm index ce3486cf3f..9b8afa63b5 100644 --- a/scm/lily.scm +++ b/scm/lily.scm @@ -94,6 +94,15 @@ (ly:error (_ "call-after-session used after session start"))) (add-hook! after-session-hook thunk #t)) +(define (make-session-variable name value) + (if (ly:undead? lilypond-declarations) + (ly:error (_ "define-session used after session start"))) + (let ((var (module-make-local-var! (current-module) name))) + (if (variable-bound? var) + (ly:error (_ "symbol ~S redefined") name)) + (variable-set! var value) + var)) + (defmacro-public define-session (name value) "This defines a variable @var{name} with the starting value @var{value} that is reinitialized at the start of each session. @@ -108,22 +117,23 @@ to their front or replacing them altogether, not by modifying parts of them. It is an error to call @code{define-session} after the first session has started." (define (add-session-variable name value) - (if (ly:undead? lilypond-declarations) - (ly:error (_ "define-session used after session start"))) - (let ((var (make-variable value))) - (module-add! (current-module) name var) - (set! lilypond-declarations (cons var lilypond-declarations)))) + (set! lilypond-declarations + (cons (make-session-variable name value) lilypond-declarations))) `(,add-session-variable ',name ,value)) (defmacro-public define-session-public (name value) "Like @code{define-session}, but also exports @var{name} into parser modules." (define (add-session-variable name value) - (if (ly:undead? lilypond-declarations) - (ly:error (_ "define-session-public used after session start"))) - (let ((var (make-variable value))) - (module-add! (current-module) name var) - (set! lilypond-exports (acons name var lilypond-exports)))) - `(,add-session-variable ',name ,value)) + (set! lilypond-exports + (acons name (make-session-variable name value) lilypond-exports))) + `(begin + ;; this is a bit icky: we place the variable right into every + ;; parser module so that both set! and define will affect the + ;; original variable in the (lily) module. However, we _also_ + ;; export it normally from (lily) for the sake of other modules + ;; not sharing the name space of the parser. + (,add-session-variable ',name ,value) + (export ,name))) (define (session-terminate) (if (ly:undead? lilypond-declarations) -- 2.39.2