[project @ 2002-01-08 07:29:07 by chak]

Some docu covering VarSet, NameSet, VarEnv, and NameEnv.
author: chak <unknown> 2002-01-08 07:29:07 +0000
committer: chak <unknown> 2002-01-08 07:29:07 +0000
commit: c9fdbbd3467f5f18f1cb03cc6a0c08190c039a15 (patch)
tree: 78968d57225971039a38f685affd5511d2d26afd
parent: ee6b1aececd9396b1404558f673488cbf4145900 (diff)
download: haskell-c9fdbbd3467f5f18f1cb03cc6a0c08190c039a15.tar.gz
2 files changed, 81 insertions, 5 deletions
diff --git a/ghc/docs/comm/index.html b/ghc/docs/comm/index.html
index 9b4d45cd7a..ab038e7cb6 100644
--- a/ghc/docs/comm/index.html
+++ b/ghc/docs/comm/index.html
@@ -6,7 +6,7 @@
   </head>
 
   <body BGCOLOR="FFFFFF">
-    <h1>The Glasgow Haskell Compiler (GHC) Commentary [v0.6]</h1>
+    <h1>The Glasgow Haskell Compiler (GHC) Commentary [v0.7]</h1>
     <p>
       <!-- Contributors: Whoever makes substantial additions or changes to the
       document, please add your name and keep the order alphabetic.  Moreover,
@@ -80,7 +80,7 @@
 
     <p><small>
 <!-- hhmts start -->
-Last modified: Mon Nov 26 19:23:12 EST 2001
+Last modified: Tue Jan  8 18:23:25 EST 2002
 <!-- hhmts end -->
     </small>
   </body>
diff --git a/ghc/docs/comm/the-beast/basicTypes.html b/ghc/docs/comm/the-beast/basicTypes.html
index 2295db5621..5c102cf9f2 100644
--- a/ghc/docs/comm/the-beast/basicTypes.html
+++ b/ghc/docs/comm/the-beast/basicTypes.html
@@ -12,7 +12,11 @@
 	href="http://cvs.haskell.org/cgi-bin/cvsweb.cgi/fptools/ghc/compiler/basicTypes/"><code>fptools/ghc/compiler/basicTypes/</code></a> 
       contains modules that define some of the essential types definition for
       the compiler - such as, identifiers, variables, modules, and unique
-      names.
+      names.  Some of those are discussed in the following.  Some more
+      detailed information on <code>Var</code>s, <code>Id</code>s, and
+      <code>TyVar</code>s is provided <a href="vars.html">elsewhere.</a>
+
+    <h2>Elementary Types</h2>
 
     <h4><code>Id</code>s</h4>
     <p>
@@ -44,9 +48,81 @@
 	(<code>IAmALoopBreaker</code>).
     </dl>
 
-    <p><small>
+    <h2>Sets, Finite Maps, and Environments</h2>
+    <p>
+      Sets of variables, or more generally names, which are needed throughout
+      the compiler, are provided by the modules <a
+      href="http://cvs.haskell.org/cgi-bin/cvsweb.cgi/fptools/ghc/compiler/basicTypes/VarSet.lhs"><code>VarSet.lhs</code></a>
+      and <a
+      href="http://cvs.haskell.org/cgi-bin/cvsweb.cgi/fptools/ghc/compiler/basicTypes/NameSet.lhs"><code>NameSet.lhs</code></a>,
+      respectively.  Moreover, frequently maps from variables (or names) to
+      other data is needed.  For example, a substitution is represented by a
+      finite map from variable names to expressions.  Jobs like this are
+      solved by means of variable and name environments implemented by the
+      modules <a
+      href="http://cvs.haskell.org/cgi-bin/cvsweb.cgi/fptools/ghc/compiler/basicTypes/VarEnv.lhs"><code>VarEnv.lhs</code></a>
+      and <a
+      href="http://cvs.haskell.org/cgi-bin/cvsweb.cgi/fptools/ghc/compiler/basicTypes/NameEnv.lhs"><code>NameEnv.lhs</code></a>.
+
+    <h4>The Module <code>VarSet</code></h4>
+    <p>
+      The Module <code>VarSet</code> provides the types <code>VarSet</code>,
+      <code>IdSet</code>, and <code>TyVarSet</code>, which are synonyms in the
+      current implementation, as <code>Var</code>, <code>Id</code>, and
+      <code>TyVar</code> are synonyms.  The module provides all the operations
+      that one would expect including the creating of sets from individual
+      variables and lists of variables, union and intersection operations,
+      element checks, deletion, filter, fold, and map functions.
+    <p>
+      The implementation is based on <a
+      href="http://cvs.haskell.org/cgi-bin/cvsweb.cgi/fptools/ghc/compiler/utils/UniqSet.lhs"><code>UniqSet</code></a>s, 
+      which in turn are simply <a href="http://cvs.haskell.org/cgi-bin/cvsweb.cgi/fptools/ghc/compiler/utils/UniqFM.lhs"><code>UniqFM</code></a>s
+      (i.e., finite maps with uniques as keys) that map each unique to the
+      variable that it represents.
+      
+    <h4>The Module <code>NameSet</code></h4>
+    <p>
+      The Module <code>NameSet</code> provides the same functionality as
+      <code>VarSet</code> only for <a
+      href="http://cvs.haskell.org/cgi-bin/cvsweb.cgi/fptools/ghc/compiler/basicTypes/Name.lhs"><code>Name<code></a>s.
+      As for the difference between <code>Name</code>s and <code>Var</code>s,
+      a <code>Var</code> is built from a <code>Name</code> plus additional
+      information (mostly importantly type information).
+
+    <h4>The Module <code>VarEnv</code></h4>
+    <p>
+      The module <code>VarEnv</code> provides the types <code>VarEnv</code>,
+      <code>IdEnv</code>, and <code>TyVarEnv</code>, which are again
+      synonyms.  The provided base functionality is similar to
+      <code>VarSet</code> with the main difference that a type <code>VarEnv
+      T</code> associates a value of type <code>T</code> with each variable in
+      the environment, thus effectively implementing a finite map from
+      variables to values of type <code>T</code>.
+    <p>
+      The implementation of <code>VarEnv</code> is also by <a
+      href="http://cvs.haskell.org/cgi-bin/cvsweb.cgi/fptools/ghc/compiler/utils/UniqFM.lhs"><code>UniqFM</code></a>,
+      which entails the slightly surprising implication that it is
+      <em>not</em> possible to retrieve the domain of a variable environment.
+      In other words, there is no function corresponding to
+      <code>VarSet.varSetElems :: VarSet -> [Var]</code> in
+      <code>VarEnv</code>.  This is because the <code>UniqFM</code> used to
+      implement <code>VarEnv</code> stores only the unique corresponding to a
+      variable in the environment, but not the entire variable (and there is
+      no mapping from uniques to variables).
+    <p>
+      In addition to plain variable environments, the module also contains
+      special substitution environments - the type <code>SubstEnv</code> -
+      that associates variables with a special purpose type
+      <code>SubstResult</code>.
+
+    <h4>The Module <code>NameEnv</code></h4>
+    <p>
+      The type <code>NameEnv.NameEnv</code> is like <code>VarEnv</code> only
+      for <code>Name</code>s.
+
+    <p><hr><small>
 <!-- hhmts start -->
-Last modified: Wed Aug  8 19:23:01 EST 2001
+Last modified: Tue Jan  8 18:29:52 EST 2002
 <!-- hhmts end -->
     </small>
   </body>
author	chak <unknown>	2002-01-08 07:29:07 +0000
committer	chak <unknown>	2002-01-08 07:29:07 +0000
commit	c9fdbbd3467f5f18f1cb03cc6a0c08190c039a15 (patch)
tree	78968d57225971039a38f685affd5511d2d26afd
parent	ee6b1aececd9396b1404558f673488cbf4145900 (diff)
download	haskell-c9fdbbd3467f5f18f1cb03cc6a0c08190c039a15.tar.gz