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For completeness, here are the changes which have been proposed for
patterns, plus all other infix operator changes needed for the new
two-superscript form. The important ones are those Joe/Brian/Paul have
made to pat(6,l). This disallows, e.g.
n + 2 + 3
but still allows:
_ + 1
n + 100
The changes to "type"/"constr" make the precedence and associativity
of "->" explicit (right infix, lower precedence than any constructor).
Thanks to Kent Karlsson for these fixes.
Notation is as for expressions.
Kevin
--------------------- Patterns -------------------------------
pat -> pat(0,n)
pat(i,n) -> [pat(i+1,n) conop(i,n)] pat(i+1,n)
| pat(i,l)
| pat(i,r)
pat(i,l) -> { pat(i,l) | pat(i+1,n) } conop (i,l) pat(i+1,n)
pat(6,l) -> - { integer | float }
-> { var | _ } + integer
pat(i,r) -> pat(i+1,n) conop(i,r) {pat(i,r) | pat(i+1,n)}
pat(10,a) -> con apat1 ... apatk
| apat
---------------------- Expressions ---------------------------
aexp -> ...
| ( exp(i+1,n) op(i,a) )
| ( op(i,a) exp(i+1,n) )
----------------------- Function LHSs ------------------------
funlhs -> afunlhs
| pat(i+1,n) varop(i,n) pat(i+1,n)
| pat(i,l) varop(i,l) pat(i+1,n)
| pat(i+1,n) varop(i,r) pat(i,r)
-------------------------- Type Arrows -----------------------
type -> type -> btype
| btype
btype -> tycon atype1 ... atypek
| atype
constr -> btype1 conop btype2
