Changes between Version 17 and Version 18 of PolymorphicComponents

Timestamp:

04/04/07 13:31:26 (6 years ago)

Author:

diatchki

Comment:

--

PolymorphicComponents

@@ -59 +59 @@
 = Report TODO List =
 List of items that need to change in the [http://darcs.haskell.org/haskell-prime-report/report/haskell-prime-draft.html draft report].
- 1. Introduce a new ''special identifier'' '''forall'''.  This identifier has a special interpretation in types and type schemes (i.e., it is ''not'' a type variable).
+ 1. Introduce a new ''special identifier'', '''forall'''.  This identifier has a special interpretation in types and type schemes (i.e., it is ''not'' a type variable).
     However, '''forall''' can still be used as an ordinary variable in expressions.
- 1. Syntax for writing type schemes
+ 2. Syntax for writing type schemes
 {{{
-scheme    = 'forall' tvar_1 .. tyvar_n '.' opt_ctxt type    (n > 0)
+scheme   -> 'forall' tvar_1 .. tyvar_n '.' opt_ctxt type    (n > 0)
           | type
 
-ascheme   = '(' scheme ')'
+ascheme  -> '(' scheme ')'
           | atype
 
-bscheme   = '(' scheme ')'
+bscheme  -> '(' scheme ')'
           | btype
 
-opt_ctxt  = context '=>'
+opt_ctxt -> context '=>'
           |
+}}}
+ 3. Syntax for algebraic datatype (Section 4.2.1)
+Change ''type'',''atype'',''btype'' to ''scheme'', ''ascheme'', ''bscheme' respectively.
+{{{
+constr   -> con [!] ascheme_1 ... [!] ascheme_k          (arity con = k, k>=0)
+          | (bscheme | ! ascheme) conop (bscheme | ! ascheme)   (infix conop)
+          | con { fielddecl1 , ... , fielddecln }       (n>=0)
+fielddecl-> vars :: (scheme | ! ascheme)
 }}}
 
 
-   1. change "atype" or modify specific sections?
    1. 4.2.1 - syntax in "Algebreic Datatype Declarations", add ''forall'' to various bits.
    1. 4.2.3 - syntax in "Datatype Renaming" ''newtype'' declarations