Commit graph

254 commits

Author SHA1 Message Date
Shea Levy afc6c1bad6 Simplify inherited attribute handling
This reduces the difference between inherited and non-inherited
attribute handling to the choice of which env to use (in recs and lets)
by setting the AttrDef::e to a new ExprVar in the parser rather than
carrying a separate AttrDef::v VarRef member.

As an added bonus, this allows inherited attributes that inherit from a
with to delay forcing evaluation of the with's attributes.

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-08-26 11:31:56 +02:00
Ivan Kozik 34bb806f74 Fix typos, especially those that end up in the Nix manual 2013-08-26 11:15:22 +02:00
Eelco Dolstra d308aeaf53 Store Nix integers as longs
So on 64-bit systems, integers are now 64-bit.

Fixes #158.
2013-08-19 12:35:03 +02:00
Eelco Dolstra 46ffcce0c3 In the profiler output, show function names (if available) 2013-08-02 18:29:23 +00:00
Eelco Dolstra 159e621d1a Overload the ‘+’ operator to support integer addition 2013-08-02 15:21:17 +00:00
Eelco Dolstra 0a470fc345 Make Env smaller
Commit 20866a7031 added a ‘withAttrs’
field to Env, which is annoying because it makes every Env structure
bigger and we allocate millions of them.  E.g. NixOS evaluation took
18 MiB more.  So this commit squeezes ‘withAttrs’ into values[0].
Probably should use a union...
2013-07-31 12:44:21 +02:00
Eelco Dolstra 8ae6d55db1 Don't use NULL 2013-07-31 12:11:14 +02:00
Shea Levy e068f49f7d Avoid thunks when a fromWith var can be looked up without evaluation
Signed-off-by: Shea Levy <shea@shealevy.com>
2013-07-31 11:48:39 +02:00
Shea Levy 20866a7031 Delay evaulation of with attrs until a variable lookup needs them
Evaluation of attribute sets is strict in the attribute names, which
means immediate evaluation of `with` attribute sets rules out some
potentially interesting use cases (e.g. where the attribute names of one
set depend in some way on another but we want to bring those names into
scope for some values in the second set).

The major example of this is overridable self-referential package sets
(e.g. all-packages.nix). With immediate `with` evaluation, the only
options for such sets are to either make them non-recursive and
explicitly use the name of the overridden set in non-overridden one
every time you want to reference another package, or make the set
recursive and use the `__overrides` hack. As shown in the test case that
comes with this commit, though, delayed `with` evaluation allows a nicer
third alternative.

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-07-31 11:48:39 +02:00
Eelco Dolstra 18a48d80a0 Show function names in error messages
Functions in Nix are anonymous, but if they're assigned to a
variable/attribute, we can use the variable/attribute name in error
messages, e.g.

while evaluating `concatMapStrings' at `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/strings.nix:18:25':
...
2013-05-16 19:08:02 +02:00
Eelco Dolstra 1b3a03f161 Show which function argument was unexpected
Fixes #116.
2013-05-16 17:56:14 +02:00
Eelco Dolstra 229567293c Shut up a compiler warning 2013-05-16 17:48:19 +02:00
Eelco Dolstra bdd4646338 Revert "Prevent config.h from being clobbered"
This reverts commit 28bba8c44f.
2013-03-08 01:24:59 +01:00
Eelco Dolstra 28bba8c44f Prevent config.h from being clobbered 2013-03-07 23:55:55 +01:00
Eelco Dolstra 5f18cd2e84 Make "${./path} ..." evaluate to a string, not a path
Wacky string coercion semantics caused expressions like

  exec = "${./my-script} params...";

to evaluate to a path (‘/path/my-script params’), because
anti-quotations are desuged to string concatenation:

  exec = ./my-script + " params...";

By constrast, adding a space at the start would yield a string as
expected:

  exec = " ${./my-script} params...";

Now the first example also evaluates to a string.
2013-02-08 20:04:04 +01:00
Eelco Dolstra 8eed07cda4 nix-env -q --out-path: Support multiple outputs
We now print all output paths of a package, e.g.

  openssl-1.0.0i  bin=/nix/store/gq2mvh0wb9l90djvsagln3aqywqmr6vl-openssl-1.0.0i-bin;man=/nix/store/7zwf5r5hsdarl3n86dasvb4chm2xzw9n-openssl-1.0.0i-man;/nix/store/cj7xvk7fjp9q887359j75pw3pzjfmqf1-openssl-1.0.0i

or (in XML mode)

  <item attrPath="openssl" name="openssl-1.0.0i" system="x86_64-linux">
    <output name="bin" path="/nix/store/gq2mvh0wb9l90djvsagln3aqywqmr6vl-openssl-1.0.0i-bin" />
    <output name="man" path="/nix/store/7zwf5r5hsdarl3n86dasvb4chm2xzw9n-openssl-1.0.0i-man" />
    <output name="out" path="/nix/store/cj7xvk7fjp9q887359j75pw3pzjfmqf1-openssl-1.0.0i" />
  </item>
2012-11-28 13:49:44 +01:00
Eelco Dolstra 6c98e6a5de Optionally ignore null-valued derivation attributes
This allows adding attributes like

  attr = if stdenv.system == "bla" then something else null;

without changing the resulting derivation on non-<bla> platforms.

We once considered adding a special "ignore" value for this purpose,
but using null seems more elegant.
2012-11-27 15:01:32 +01:00
Eelco Dolstra 408a7bfac1 nix-instantiate: Fix read-only evaluation 2012-11-26 17:41:10 +01:00
Eelco Dolstra 88164325fa Fix a segfault when auto-calling a "a@{...}" function
Since the called function can return its argument attribute set
(e.g. "a"), the latter should not be allocated on the stack.

Reported by Shea.
2012-11-09 15:09:31 +01:00
Eelco Dolstra 0a7084567f Add a ‘--repair’ flag to nix-instantiate
This allows repairing corrupted derivations and other source files.
2012-10-03 15:09:18 -04:00
Eelco Dolstra 76e88871b2 Templatise tokenizeString() 2012-09-19 15:43:23 -04:00
Eelco Dolstra e94806d030 Merge branch 'master' into no-manifests 2012-08-27 11:09:07 -04:00
Eelco Dolstra 767101824a Avoid concatenating lists of one string 2012-08-13 15:10:29 -04:00
Eelco Dolstra e5c589d271 Don't allocate empty lists
This saves about 4 MB when evaluating a NixOS system configuration.
2012-08-13 15:02:09 -04:00
Eelco Dolstra 3e89ef597c Optimise concatenating a list to an empty list
More precisely, in concatLists, if all lists except one are empty,
then just return the non-empty list.  This reduces the number of list
element allocations by 32% when evaluating a NixOS system
configuration.
2012-08-13 14:58:54 -04:00
Eelco Dolstra 198d0338be Add a primop ‘concatLists’
This can serve as a generic efficient list builder.  For instance, the
function ‘catAttrs’ in Nixpkgs can be rewritten from

  attr: l: fold (s: l: if hasAttr attr s then [(getAttr attr s)] ++ l else l) [] l

to

  attr: l: builtins.concatLists (map (s: if hasAttr attr s then [(getAttr attr s)] else []) l)

Statistics before:

  time elapsed: 1.08683
  size of a value: 24
  environments allocated: 1384376 (35809568 bytes)
  list elements: 6946783 (55574264 bytes)
  list concatenations: 37434
  values allocated: 1760440 (42250560 bytes)
  attribute sets allocated: 392040
  right-biased unions: 186334
  values copied in right-biased unions: 591137
  symbols in symbol table: 18273
  number of thunks: 1297673
  number of thunks avoided: 1380759
  number of attr lookups: 430802
  number of primop calls: 628912
  number of function calls: 1333544

Statistics after (including new catAttrs):

  time elapsed: 0.959854
  size of a value: 24
  environments allocated: 1010198 (26829296 bytes)
  list elements: 1984878 (15879024 bytes)
  list concatenations: 30488
  values allocated: 1589760 (38154240 bytes)
  attribute sets allocated: 392040
  right-biased unions: 186334
  values copied in right-biased unions: 591137
  symbols in symbol table: 18274
  number of thunks: 1040925
  number of thunks avoided: 1038428
  number of attr lookups: 438419
  number of primop calls: 474844
  number of function calls: 959366
2012-08-13 01:53:10 -04:00
Eelco Dolstra 4ccd48ce24 Add a "filter" primop
Evaluation of a NixOS configuration spends quite a lot of time in the
"filter" function in Nixpkgs.  As implemented in Nixpkgs, this is a
O(n^2) operation, so it's a good candidate for providing a more
efficient (i.e. primop) implementation.  Using it gives a ~10% speed
increase and a significant reduction in the number of evaluations.

Statistics before (on a NixOS system config):

  time elapsed: 1.3258
  size of a value: 24
  environments allocated: 1980939 (50127080 bytes)
  list elements: 14679308 (117434464 bytes)
  list concatenations: 50828
  values allocated: 2098938 (50374512 bytes)
  attribute sets allocated: 392040
  right-biased unions: 186334
  values copied in right-biased unions: 591137
  symbols in symbol table: 18271
  number of thunks: 1645752
  number of thunks avoided: 1921196
  number of attr lookups: 430798
  number of primop calls: 838807
  number of function calls: 1930107

Statistics after:

  time elapsed: 1.17982
  size of a value: 24
  environments allocated: 1543334 (39624560 bytes)
  list elements: 9612638 (76901104 bytes)
  list concatenations: 37434
  values allocated: 1854933 (44518392 bytes)
  attribute sets allocated: 392040
  right-biased unions: 186334
  values copied in right-biased unions: 591137
  symbols in symbol table: 18272
  number of thunks: 1392467
  number of thunks avoided: 1507311
  number of attr lookups: 430801
  number of primop calls: 691600
  number of function calls: 1492502
2012-08-13 00:28:08 -04:00
Eelco Dolstra 62f72eb9e1 Add some more evaluations stats 2012-08-12 23:41:48 -04:00
Eelco Dolstra e82767910c Add some basic profiling support to the evaluator
Setting the environment variable NIX_COUNT_CALLS to 1 enables some
basic profiling in the evaluator.  It will count calls to functions
and primops as well as evaluations of attributes.

For example, to see where evaluation of a NixOS configuration spends
its time:

$ NIX_SHOW_STATS=1 NIX_COUNT_CALLS=1 ./src/nix-instantiate/nix-instantiate '<nixos>' -A system --readonly-mode
...
calls to 39 primops:
    239532 head
    233962 tail
    191252 hasAttr
...
calls to 1595 functions:
    224157 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/lists.nix:17:19'
    221767 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/lists.nix:17:14'
    221767 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/lists.nix:17:10'
...
evaluations of 7088 attributes:
    167377 undefined position
    132459 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/attrsets.nix:119:41'
     47322 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/attrsets.nix:13:21'
...
2012-08-12 23:29:28 -04:00
Eelco Dolstra 97421eb5ec Refactor settings processing
Put all Nix configuration flags in a Settings object.
2012-07-30 19:55:41 -04:00
Eelco Dolstra 1217204c81 Remove dead code 2012-07-17 14:07:52 -04:00
Eelco Dolstra f491ae97d4 * Inline some functions and get rid of the indirection through
EvalState::eval().  This gives a 12% speedup on ‘nix-instantiate
  /etc/nixos/nixos/ -A system --readonly-mode’ (from 1.01s to 0.89s).
2012-02-04 13:50:25 +00:00
Eelco Dolstra 2bda12ef3b * Print elapsed evaluation time. 2012-02-04 13:27:11 +00:00
Eelco Dolstra 330df4b4db * Allow comparisons between derivations by comparing the outPath
attributes.
2012-01-19 23:08:47 +00:00
Eelco Dolstra 9fe24c5a0d * Don't create thunks for simple constants (integers, strings, paths)
and allocate them only once.
* Move Value and related functions into value.hh.
2012-01-07 17:26:33 +00:00
Eelco Dolstra b52966e821 * Remove dead code. 2012-01-04 21:47:48 +00:00
Eelco Dolstra 35f2a6ba82 * Don't use dynamic_cast, it's very slow. "nix-instantiate
/etc/nixos/nixos -A system" spent about 10% of its time in
  dynamic_cast.
2012-01-04 21:24:11 +00:00
Eelco Dolstra 921111d197 * Move the implementation of the ‘derivation’ primop into a separate
file.
2012-01-03 14:01:47 +00:00
Shea Levy 24b65937e1 Remove the unused sCurrentOutput symbol 2011-11-06 06:28:34 +00:00
Shea Levy 2721e9f56f Merge from trunk 2011-11-06 00:13:09 +00:00
Eelco Dolstra a12095d3be * In printValueAsXML, handle the case where a "type" attribute is not
a string.  This happens in the NixOS option system.
* Remove a bogus comparison of a unsigned integer with -1.
2011-10-27 19:06:23 +00:00
Shea Levy ffa038f66d Add an sCurrentOutput member to EvalState 2011-09-16 11:30:44 +00:00
Eelco Dolstra 2d663b502d * Cache the result of file evaluation (i.e, memoize evalFile()). This
prevents files from being evaluated and stored as values multiple
  times.  For instance, evaluation of the ‘system’ attribute in NixOS
  causes ‘nixpkgs/pkgs/lib/lists.nix’ to be evaluated 2019 times.

  Caching gives a modest speedup and a decent memory footprint
  reduction (e.g., from 1.44s to 1.28s, and from 81 MiB to 59 MiB with
  GC_INITIAL_HEAP_SIZE=100000 on my system).
2011-08-06 19:45:43 +00:00
Eelco Dolstra 00a724ebc6 * Remove a debug statement. 2011-08-06 18:24:43 +00:00
Eelco Dolstra 07340b8be7 * Add the Nix corepkgs to the end of the search path. This makes it
possible for other Nix expressions to use corepkgs (mostly useful
  for the buildenv function).
2011-08-06 18:23:38 +00:00
Eelco Dolstra 1ecc97b6bd * Add a Nix expression search path feature. Paths between angle
brackets, e.g.

    import <nixpkgs/pkgs/lib>

  are resolved by looking them up relative to the elements listed in
  the search path.  This allows us to get rid of hacks like

    import "${builtins.getEnv "NIXPKGS_ALL"}/pkgs/lib"

  The search path can be specified through the ‘-I’ command-line flag
  and through the colon-separated ‘NIX_PATH’ environment variable,
  e.g.,

    $ nix-build -I /etc/nixos ...

  If a file is not found in the search path, an error message is
  lazily thrown.
2011-08-06 16:05:24 +00:00
Eelco Dolstra 54945a2950 * Refactoring: move parseExprFromFile() and parseExprFromString() into
the EvalState class.
2011-08-06 13:02:55 +00:00
Eelco Dolstra 0a623a10c7 * Allow a default value in attribute selection by writing
x.y.z or default

  (as originally proposed in
  https://mail.cs.uu.nl/pipermail/nix-dev/2009-September/002989.html).

  For instance, an expression like

    stdenv.lib.attrByPath ["features" "ckSched"] false args

  can now be written as

    args.features.ckSched or false
2011-07-13 12:19:57 +00:00
Eelco Dolstra 2b9e29b1c8 * Change the right-hand side of the ‘.’ operator from an attribute to
an attribute path.  This is a refactoring to support default values.
2011-07-06 12:28:57 +00:00
Eelco Dolstra 5637037802 * In the ‘?’ operator, allow attribute paths. For instance, you can
write ‘attrs ? a.b’ to test whether ‘attrs’ has an attribute ‘a’
  containing an attribute ‘b’.  This is more convenient than ‘attrs ?
  a && attrs.a ? b’.

  Slight change in the semantics: it's no longer an error if the
  left-hand side of ‘?’ is not an attribute set.  In that case it just
  returns false.  So, ‘null ? foo’ no longer throws an error.
2011-07-06 10:58:17 +00:00
Eelco Dolstra 538b7caab0 * Don't allocate a big initial GC address space on machines with
little RAM.  Even if the memory isn't actually used, it can cause
  problems with the overcommit heuristics in the kernel.  So use a VM
  space of 25% of RAM, up to 384 MB.
2011-02-10 14:31:04 +00:00
Eelco Dolstra 5a6b039802 * Don't call GC_expand_hp unless we're actually using the garbage
collector.
2011-02-09 22:59:50 +00:00
Eelco Dolstra 0c4828ea05 * new(UseGC) is inexplicably slower than GC_MALLOC, so prefer the
latter.
2010-10-28 12:50:01 +00:00
Eelco Dolstra e11e6fb1c6 * Handle out of memory condition. 2010-10-28 12:29:40 +00:00
Eelco Dolstra 43535499f3 * When allocating an attribute set, reserve enough space for all
elements.  This prevents the vector from having to resize itself.
2010-10-24 20:09:37 +00:00
Eelco Dolstra e0b7fb8f27 * Keep attribute sets in sorted order to speed up attribute lookups.
* Simplify the representation of attributes in the AST.
* Change the behaviour of listToAttrs() in case of duplicate names.
2010-10-24 19:52:33 +00:00
Eelco Dolstra 2dc6d50941 * Don't create thunks for variable lookups (if possible). This
significantly reduces the number of values allocated (e.g. from 8.7m
  to 4.9m for the Bittorrent test).
2010-10-24 14:20:02 +00:00
Eelco Dolstra 0b305c534f * Store attribute sets as a vector instead of a map (i.e. a red-black
tree).  This saves a lot of memory.  The vector should be sorted so
  that names can be looked up using binary search, but this is not the
  case yet.  (Surprisingly, looking up attributes using linear search
  doesn't have a big impact on performance.)

  Memory consumption for

    $ nix-instantiate /etc/nixos/nixos/tests -A bittorrent.test --readonly-mode

  on x86_64-linux with GC enabled is now 185 MiB (compared to 946
  MiB on the trunk).
2010-10-24 00:41:29 +00:00
Eelco Dolstra a247d20604 * Fix compiling without Boehm.
* Fix the stats.
2010-10-23 22:58:24 +00:00
Eelco Dolstra b2ba62170c * Optimise string constants by putting them in the symbol table. 2010-10-23 21:11:59 +00:00
Eelco Dolstra 8ac06726b9 * Make Value smaller by not storing redundant PrimOp info.
* Clear pointers in Values after overwriting them to make sure that no
  objects are kept alive unnecessarily.
2010-10-23 20:07:47 +00:00
Eelco Dolstra 3f66cfb96b * Remove allocValues(). 2010-10-23 18:18:07 +00:00
Eelco Dolstra 4dee289550 * In environments, store pointers to values rather than values. This
improves GC effectiveness a bit more (because a live value doesn't
  keep other values in the environment plus the parent environments
  alive), and removes the need for copy nodes.
2010-10-22 15:51:52 +00:00
Eelco Dolstra 41c45a9b31 * Store Value nodes outside of attribute sets. I.e., Attr now stores
a pointer to a Value, rather than the Value directly.  This improves
  the effectiveness of garbage collection a lot: if the Value is
  stored inside the set directly, then any live pointer to the Value
  causes all other attributes in the set to be live as well.
2010-10-22 14:47:42 +00:00
Eelco Dolstra 64c3325b0b * Make building against the Boehm GC a configure option. 2010-10-22 13:39:15 +00:00
Eelco Dolstra 76feaf016a * Keep some more stats. 2010-10-20 15:48:00 +00:00
Eelco Dolstra e879a0371b * Use the Boehm garbage collector to reclaim unused memory in the Nix
expression evaluator.
2010-10-20 11:38:30 +00:00
Eelco Dolstra df50916e46 * Oops - "null" was displayed as "true". 2010-08-27 12:10:56 +00:00
Eelco Dolstra 6d6200f37a * Optimisation in the // operator: if one of the sets is empty, return
the other set.
2010-08-02 16:31:05 +00:00
Eelco Dolstra f16fe2af8d * builtins.toXML: propagate the string context. This is a regression
from the old ATerm-based evaluator.
2010-06-10 10:29:50 +00:00
Eelco Dolstra 1ab67cf437 2010-06-02 09:43:04 +00:00
Eelco Dolstra 93cd5a4a13 * The << operator on values should be const. 2010-05-18 10:36:37 +00:00
Eelco Dolstra b2235d81d1 * Restore the __overrides feature that was lost somewhere in the
fast-eval branch.
2010-05-15 08:10:12 +00:00
Eelco Dolstra bd25ac2260 * Print attributes in sorted order. 2010-05-12 12:15:49 +00:00
Eelco Dolstra 01e58adce0 * Store position info for inherited attributes. 2010-05-07 12:43:57 +00:00
Eelco Dolstra e2d5e40f4f * Keep track of the source positions of attributes. 2010-05-07 12:11:05 +00:00
Eelco Dolstra 84ce7ac76f * Store attribute positions in the AST and report duplicate attribute
errors with position info.
* For all positions, use the position of the first character of the
  first token, rather than the last character of the first token plus
  one.
2010-05-06 16:46:48 +00:00
Eelco Dolstra 0bc468f195 * Simplify the implementation of `with'. This gives a 7% speedup in
evaluating the NixOS system configuration.
2010-04-22 15:08:09 +00:00
Eelco Dolstra 2d7636529f * String equality tests should take the context into account. All the
evaluation test cases now succeed.
2010-04-22 09:54:11 +00:00
Eelco Dolstra 0777448ca6 * Fixed builtins.genericClosure. 2010-04-21 15:57:11 +00:00
Eelco Dolstra fe2d869e04 * Store user environment manifests as a Nix expression in
$out/manifest.nix rather than as an ATerm.

  (Hm, I thought I committed this two days ago...)
2010-04-21 15:08:58 +00:00
Eelco Dolstra 5c31995bb8 * Updated some more primops. 2010-04-16 15:13:47 +00:00
Eelco Dolstra 8ca4a001cb * Improve sharing a bit. 2010-04-16 14:03:26 +00:00
Eelco Dolstra 497e4ad126 * Remove some redundant tests. 2010-04-16 13:51:01 +00:00
Eelco Dolstra 02c1dac909 * In an nested with' where the inner with is a variable (with ...;
with someVar; ...'), the contents of the variable would be
  clobbered.  (The attributes in the outer `with' were added to the
  variable.)
2010-04-16 13:44:02 +00:00
Eelco Dolstra 04c4bd3624 * Store lists as lists of pointers to values rather than as lists of
values.  This improves sharing and gives another speed up.
  Evaluation of the NixOS system attribute is now almost 7 times
  faster than the old evaluator.
2010-04-15 00:37:36 +00:00
Eelco Dolstra e41b5828db * Better stats. 2010-04-14 23:48:46 +00:00
Eelco Dolstra d39d3c6264 * Implemented inherit. 2010-04-14 23:25:05 +00:00
Eelco Dolstra 267dc693d2 * Fix builtins. 2010-04-14 22:59:39 +00:00
Eelco Dolstra 81de12bc8f * Refactoring: move variable uses to a separate class. 2010-04-14 15:14:23 +00:00
Eelco Dolstra 110d155778 * Implemented withs. 2010-04-14 15:01:04 +00:00
Eelco Dolstra 9985230c00 * After parsing, compute level/displacement pairs for each variable
use site, allowing environments to be stores as vectors of values
  rather than maps.  This should speed up evaluation and reduce the
  number of allocations.
2010-04-14 14:42:32 +00:00
Eelco Dolstra 85d13c8f93 * Change the semantics of "with" so that inner "withs" take
precedence, i.e. `with {x=1;}; with {x=2;}; x' evaluates to 2'.
  This has a simpler implementation and seems more natural.  There
  doesn't seem to be any code in Nixpkgs or NixOS that relies on the
  old behaviour.
2010-04-14 08:37:08 +00:00
Eelco Dolstra 816f9c0f6f * Use std::tr1::unordered_set instead of std::set for the symbol
table.  This gives a 10% speed increase on `nix-instantiate
  /etc/nixos/nixos -A system --readonly-mode'.
2010-04-13 14:34:11 +00:00
Eelco Dolstra 7d47498b5e * Evaluate lets directly (i.e. without desugaring to `rec { attrs...;
<let-body> = e; }.<let-body>).  This prevents the unnecessary
  allocation of an attribute set.
2010-04-13 13:42:25 +00:00
Eelco Dolstra ac1e8f40d4 * Use a symbol table to represent identifiers and attribute names
efficiently.  The symbol table ensures that there is only one copy
  of each symbol, thus allowing symbols to be compared efficiently
  using a pointer equality test.
2010-04-13 12:25:42 +00:00
Eelco Dolstra 10e8b1fd15 * Finished the ATerm-less parser. 2010-04-12 23:33:23 +00:00
Eelco Dolstra d4f0b0fc6c * Indented strings. 2010-04-12 22:03:27 +00:00
Eelco Dolstra a60317f20f * More missing constructs. 2010-04-12 21:21:24 +00:00
Eelco Dolstra 4d6ad5be17 * Don't use ATerms for the abstract syntax trees anymore. Not
finished yet.
2010-04-12 18:30:11 +00:00