diff options
Diffstat (limited to 'src/interp/g-util.boot')
| -rw-r--r-- | src/interp/g-util.boot | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/src/interp/g-util.boot b/src/interp/g-util.boot index 437c0427..7e15d637 100644 --- a/src/interp/g-util.boot +++ b/src/interp/g-util.boot @@ -68,12 +68,18 @@ mkBind(inits,expr) == mkBind([:inits,:inits'],expr') ['%bind,inits,expr] -splitAssignments u == main(u,nil) where +++ Given a (possibly multiple) assignment expression `u', return +++ the list of all assignment sub-expressions that must be evaluated before +++ effecting the toplevel assignment indicated by `u'. In that case, +++ modify `u' in place to reflect the new right-hand-side. +splitAssignments! u == main(u,nil) where main(u,l) == u is ['%LET,x,v] => - v is ['%LET,y,.] => main(v,[['%LET,x,y],:l]) - [u,:l] - nil + v is ['%LET,y,.] => + second(u.args) := y + [:main(v,l),v] + l + l ++ We have a list `l' of expressions to be executed sequentially. ++ Splice in any directly-embedded sequence of expressions. |