ghc/docs/release_notes/0-08-notes.lit

   1 0.08 was not an announced release, so these notes are of historical
   2 interest, at best.
   3
   4 %************************************************************************
   5 %*                                                                      *
   6 \subsection[0-08-new-docs]{New documentation, especially for hackers!}
   7 %*                                                                      *
   8 %************************************************************************
   9
  10 %************************************************************************
  11 %*                                                                      *
  12 \subsection[0-08-new-in-usage]{Main user-visible changes}
  13 %*                                                                      *
  14 %************************************************************************
  15
  16 \begin{description}
  17 %-------------------------------------------------------------------
  18 \item[@ghc@ driver flag fiddling:]
  19 These things change... A good thing to try is \tr{ghc -help}, unless
  20 of course you think the documentation might be right (in which case
  21 look there :-).
  22
  23 %-------------------------------------------------------------------
  24 \item[@ghc@ driver more ``policy-free'':]
  25
  26 The driver no longer has great wads of built-in options for its
  27 constituent phases (parser, Haskell compiler, C compiler, etc.).  It
  28 is much easier to configure these (if required) at build time.  A
  29 better idea, which we use, is to wired in very few options, but to use
  30 the ``make world'' machinery to ensure that the desired (wads of
  31 options) are always passed explicitly.
  32
  33 %-------------------------------------------------------------------
  34 \item[-OC:] We got rid of the \tr{-OC} flag.
  35 \end{description}
  36
  37 %************************************************************************
  38 %*                                                                      *
  39 \subsection[0-08-new-in-compiler]{To do with the compiler proper}
  40 %*                                                                      *
  41 %************************************************************************
  42
  43 \begin{description}
  44 %-------------------------------------------------------------------
  45 \item[``Renamer'' is in:]
  46 Essentially, this implements module-system stuff.  Checks for
  47 naming/scoping errors have been moved out of the typechecker into the
  48 renamer, which should be faster.
  49
  50 %-------------------------------------------------------------------
  51 \item[Interface-file (\tr{.hi} file) generation:]
  52 It works.
  53
  54 %-------------------------------------------------------------------
  55 \item[Ambiguous-type resolution:]
  56 It's basically right now, except that we still don't grok @default@
  57 declarations (which we have yet to see in a real Haskell program :-).
  58
  59 %-------------------------------------------------------------------
  60 \item[Smaller C output:]
  61
  62 %-------------------------------------------------------------------
  63 \item[Code generator:]
  64 Improvements related to the information carried around about closures
  65 (@ClosureInfo@ and @LambdaFormInfo@ types); matches the STG-machine paper.
  66
  67 CAFs fully supported (notably updatable ones).
  68
  69 Black-holing (at garbage-collection time) fully supported.
  70
  71 %-------------------------------------------------------------------
  72 \item[Simplifiers:]
  73 Further work on the @Core@-to-@Core@ local-transformation passes (in
  74 \tr{compiler/simplCore/}).  Also, we have added
  75 some @STG@-to-@STG@ transformations; for example, floating @lets@
  76 outward is most conveniently done at the STG level...
  77
  78 %-------------------------------------------------------------------
  79 \item[Cost-centre-style profiling:]
  80
  81 %-------------------------------------------------------------------
  82 \item[Improvements to basic datatypes:]
  83 Notably to @Ids@ (\tr{basicTypes/Id.lhs}) and names
  84 (\tr{basicTypes/NameTypes.lhs}).  There is a new compiler-wide class,
  85 @NamedThing@ (\tr{utils/Outputable.lhs}).  Essentially it is easier to
  86 ask of an entity: where did you come from? (e.g., PreludeCore?,
  87 imported?) what are you? (a data-constructor? a dictionary selector?)
  88 what is your original name? where are you going? (exported or not...)
  89 \end{description}
  90
  91 %************************************************************************
  92 %*                                                                      *
  93 \subsection[0-08-new-in-compiler-contrib]{In contributed bits of the compiler}
  94 %*                                                                      *
  95 %************************************************************************
  96
  97 \begin{description}
  98 \item[Evaluation-transformer bits:]
  99 Denis Howe has sent us an initial version (\tr{compiler/evalTran}).
 100 It isn't used by default, but is presumably play-withable...
 101
 102 This @Core@-to-@Core@ transformation makes all lets of the form
 103 \begin{verbatim}
 104 let VAR = eval EXPR in ...
 105 \end{verbatim}
 106 strict.  @eval@ is a dummy name which is thrown away (i.e., @eval x = x@).
 107 \end{description}
 108
 109 Please send us {\em your} bits for next time!
 110
 111 %************************************************************************
 112 %*                                                                      *
 113 \subsection[0-08-new-in-libraries]{In @Prelude@ and runtime support}
 114 %*                                                                      *
 115 %************************************************************************
 116
 117 Prelude is 1.2.
 118
 119 The compiler has basically all of @PreludeCore@ wired into it (see
 120 \tr{compiler/prelude/}); the rest is brought in with a straightforward
 121 \tr{import Prelude} (which brings in \tr{imports/Prelude.hi}).  [The
 122 old \tr{MiniPrel*} files are dead and unmissed.]
 123
 124 %************************************************************************
 125 %*                                                                      *
 126 \subsection[0-08-new-in-mkworld]{In distribution/build/installation machinery}
 127 %*                                                                      *
 128 %************************************************************************
 129
 130 The ``make world'' machinery has many small improvements.
 131
 132 It works notably better in a shared-symlink-tree world (which we use
 133 at Glasgow).
 134
 135 We have abandoned efforts to use one build tree for making object
 136 files for multiple platforms.  We can make simpler Makefiles as a
 137 result.
 138
 139 There's a new standard setup, called \tr{fast}.  The name is
 140 inappropriate at present, but it is intended to be for people who
 141 value compiled-code-speed above all else (within reason, of course).
 142
 143 %************************************************************************
 144 %*                                                                      *
 145 \subsection[0-08-new-misc]{Miscellaneous new things}
 146 %*                                                                      *
 147 %************************************************************************
 148
 149 New version of Denis Howe's \tr{mira2hs} script.