1. 18 Mar, 2015 1 commit
  2. 16 Feb, 2015 4 commits
    • Kim Nguyễn's avatar
      Remove the a workaround the AST for patterns that was used to · 4f49a2af
      Kim Nguyễn authored
      correctly handle insantiated types in regular expressions.
      4f49a2af
    • Kim Nguyễn's avatar
      Fix the handling of polymorphic variables in the lexer. The solution · 36b83c45
      Kim Nguyễn authored
      to use two lexers (depending on whether we are between square brackets
      or not) is too brittle (it crudely tries to parse
       ``( [whitespace] 'a  [whitespace] )'' as a variable, to force the user
      to write the variable beetween parenthesis. However this does not scale
      to types with two arguments (says [ t ('a, 'b) ]).
      
      We use a simpler heuristic (with look ahead)
      
      (1) try to see if the regular expression
      
      ' (anything but ', \n)* '(anything but the first letter of an identifier)
      
      can be found. If so, we put back the lexeme in the buffer and parse it as as
      a string.
      
      (2) if (1) failed, try to parse it as a variable
      
      (3) if (3) failed, try to parse it again as a string. We are
      guaranteed to fail here but it means we have a malformed string, so we
      parse as a string to get a proper error message.
      
      The only thing this does not cover are cases like
      type t = [ 'abcd'Int ]
      which was tokenized before as [, 'abcd', Int, ]
      and is now tokenized as [, 'abcd, 'Int, ]
      It does not seem to be a problem in practice though (since in the code
      I have seen thus far, people were at least putting a space).
      it is easy to emmit a warning in this case, suggesting the user to add
      a whitespace to get the old behaviour back.
      36b83c45
    • Kim Nguyễn's avatar
    • Kim Nguyễn's avatar
      Implement the syntax ``t (t1, …, tn)'' for type instantiation, without · 07bc7bc1
      Kim Nguyễn authored
      requiring an abscence of whitespace between ``t'' and ``(''.  Outside
      of regular expression contexts, ``t (t1, …, tn)'' is parsed with a
      higher precedence than & and \, to allow one to write
      ``t (Int) & Bool'' without extra parentheses (i.e.
      ``(t (Int)) & Bool'').  Inside a regular expression, type
      instantiation and sequencing become ambiguous, and there is no way to
      distinguish syntactically: ``[ Int (Int, Int) ]'' from
      ``[ t (Int, Int) ]''. The former should resolve to a sequence while
      the latter only makes sense as an instantiation (if ``t'' is a
      parametric type). Both are treated as element sequencing and
      disambiguated during identifier resolution (more precisely during the
      "derecurse" phase, before typechecking).
      
      Note that due to the lower precedence of sequencing w.r.t to other
      regular expression constructs, a type ``[ t (Int)* ]'' will be parsed
      correctly, but yield an error message saying that t is not fully
      intantiated. One has to write ``[ (t (Int))* ]'' which is similar to
      function applications for expressions.
      
      Finally, we also re-order sequencing after typing to always group a
      potential type instantiation with its argument, i.e. we transform
      sequences such as
      ``[ t1 t2 t3 ... tn ]'' (which are parsed as
      ``[ (((t1 t2) t3) ... tn) ]'' because sequence concatenation is
      left-associative) into ``[ ... (ti tj) ... ]'' if ``ti'' is an
      identifier and ``tj'' is of the form ``(s1,...,sk)''. This is sound
      because concatenation of regular expression is associative (and the
      original sequence would fail, anyway).
      07bc7bc1
  3. 15 Feb, 2015 1 commit
  4. 19 Sep, 2014 1 commit
  5. 12 Sep, 2014 2 commits
  6. 09 Sep, 2014 1 commit
    • Pietro Abate's avatar
      New syntax for parametric types · f1235de1
      Pietro Abate authored
      now we can write types as
      type t( 'a) = <a>'a
      
      and patterns can contain type instantiations
      let f = fun (t('a) -> [ t('a)* ]) x -> [ x ];;
      let id = fun (t(Int) -> [ t(Int)* ]) x -> [ x ];;
      
      Note: parametric types must be written as "IDENT(" without space.
      f1235de1
  7. 08 Sep, 2014 3 commits
  8. 28 Aug, 2014 1 commit
    • Pietro Abate's avatar
      More var.ml cleanup · 737730a2
      Pietro Abate authored
      - Var identifiers are now of type U.t instead of string
      - Remove TVar from ast. Polymorphic variables are just types
      737730a2
  9. 19 Aug, 2014 1 commit
  10. 23 Jul, 2014 1 commit
  11. 11 Jul, 2014 3 commits
  12. 01 Jul, 2014 1 commit
  13. 23 Jun, 2014 1 commit
  14. 22 Jun, 2014 1 commit
  15. 19 Jun, 2014 6 commits
  16. 15 Jan, 2014 1 commit
    • Pietro Abate's avatar
      Parse type variables as patterns · 6ee8a6b0
      Pietro Abate authored
      - type variables are now correctly parsed as patterns
        and not as expressions
      
      - Add a new module Var that contains all the type variables
        related machinery
      
      - Remove old functions and unit tests about BoolVar of only
        variables, since now variables are always stored associated
        with one or more kinds
      6ee8a6b0
  17. 06 Jan, 2014 1 commit
  18. 11 Dec, 2013 1 commit
  19. 03 Dec, 2013 2 commits
  20. 05 Oct, 2007 7 commits