diff options
| -rw-r--r-- | portToNewSyntax/1.3-and-2.0-differences.txt | 70 | ||||
| -rw-r--r-- | portToNewSyntax/portToNewSyntax.icl | 3 |
2 files changed, 35 insertions, 38 deletions
diff --git a/portToNewSyntax/1.3-and-2.0-differences.txt b/portToNewSyntax/1.3-and-2.0-differences.txt index 85b338b..3608b28 100644 --- a/portToNewSyntax/1.3-and-2.0-differences.txt +++ b/portToNewSyntax/1.3-and-2.0-differences.txt @@ -1,4 +1,5 @@ -This file describes differences between Clean 1.3.x and Clean 2.x +This file describes differences between Clean 1.3.x and Clean 2.x. It is aimed +to help you to port Clean 1.3.x programs to Clean 2.x First of all: Clean 2.x is not downward compatible with Clean 1.3.x. Probably you have to change your 1.3.x sources to get them through the Clean 2.x @@ -15,7 +16,7 @@ New Features in Clean 2.0 ------------------------- Clean 2.x has dynamic types, multiparameter type classes and generic classes. -For these items we see the Clean language report. +For these items see the Clean language report. With Clean 2.x cyclic dependencies between dcl modules are allowed. @@ -28,21 +29,9 @@ can enforce strict evaluation using the strict hash let (#!). Differences in the Type System ------------------------------ -1. - For multiparameter type classes a small change in the syntax for instance - definitions was necessary. In Clean 1.3.x it was assumed that every instance - definition only has one type argument. So in the following 1.3.x instance - definition - - instance c T1 T2 - - the type "(T1 T2)" was meant (the type T1 with the argument T2). If this was - the intention then this should be written in Clean 2.x as - - instance c (T1 T2) - - otherwise T1 and T2 will be interpreted as two types. - +1. Array handling has become different, see section "Differences in the + Standard environment + 2. There is a difference in resolving overloading. Consider the following code: @@ -110,26 +99,16 @@ Differences in the Type System is not valid. 5. - There was a bug in the uniqueness typing system: Records or data constructors - could have existentially quantified variables, whose uniqueness attribute - did _not_ propagate. So it was possible to write - - f :: *{Int} -> Int - f a - #! a0 = a.[0] - a = { a & [0] = a0+1 } - = a.[0] - - :: T = E..x: C (x->Int) x - - getInt (C f x) = f x - - Start - # myObject = C f {0} - = (getInt myObject, getInt myObject) - - which resulted in (1,2), which isn't that much referential transparent. This - bug has been solved in Clean 2.x. + The Clean 1.3.x compiler has chosen lazy arrays whenever there was a choice. + The Clean 2.x compiler will complain in these cases that internal overloading + could not be solved. E.g. + + Start = size {1} + + is accepted by Clean 1.3.x but not by Clean 2.x. + +6. + Some bugs in the uniqueness typing system were fixed. Differences in the Module System -------------------------------- @@ -245,6 +224,21 @@ Miscellaneous Differences ------------------------- 1. + For multiparameter type classes a small change in the syntax for instance + definitions was necessary. In Clean 1.3.x it was assumed that every instance + definition only has one type argument. So in the following 1.3.x instance + definition + + instance c T1 T2 + + the type "(T1 T2)" was meant (the type T1 with the argument T2). If this was + the intention then this should be written in Clean 2.x as + + instance c (T1 T2) + + otherwise T1 and T2 will be interpreted as two types. + +2. Anonymous uniqueness attributes in type contexts are not allowed in Clean 2.x. So in the following function type @@ -252,7 +246,7 @@ Miscellaneous Differences simply remove the point. -2. +3. There are differences in some libraries. See the library's documentation. The Preprocessor diff --git a/portToNewSyntax/portToNewSyntax.icl b/portToNewSyntax/portToNewSyntax.icl index 85dbef8..ebaf118 100644 --- a/portToNewSyntax/portToNewSyntax.icl +++ b/portToNewSyntax/portToNewSyntax.icl @@ -150,6 +150,9 @@ imported_decl_to_opt_string all_expl_imp_decls dcl_ident dcl_index STE_Type def_ _ -> dcl_ident.id_name) = (Yes dcl_string, dcl_modules) +imported_decl_to_opt_string all_expl_imp_decls dcl_ident dcl_index STE_Generic def_mod_index + dcl_modules + = (Yes ("generic "+++dcl_ident.id_name+++"(..)"), dcl_modules) // only for portToNewSyntax type_to_string (TA {type_name} _) = possibly_replace_predef_symbols type_name.id_name |