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Merge branch 'master' into no-manifests

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This commit is contained in:
Eelco Dolstra 2012-08-27 11:09:07 -04:00
commit e94806d030
20 changed files with 325 additions and 139 deletions
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81
src/libexpr/primops.cc
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@ -719,7 +719,7 @@ static void prim_attrNames(EvalState & state, Value * * args, Value & v)
/* Dynamic version of the `.' operator. */
static void prim_getAttr(EvalState & state, Value * * args, Value & v)
void prim_getAttr(EvalState & state, Value * * args, Value & v)
{
string attr = state.forceStringNoCtx(*args[0]);
state.forceAttrs(*args[1]);
@ -728,6 +728,7 @@ static void prim_getAttr(EvalState & state, Value * * args, Value & v)
if (i == args[1]->attrs->end())
throw EvalError(format("attribute `%1%' missing") % attr);
// !!! add to stack trace?
if (state.countCalls && i->pos) state.attrSelects[*i->pos]++;
state.forceValue(*i->value);
v = *i->value;
}
@ -873,19 +874,33 @@ static void prim_isList(EvalState & state, Value * * args, Value & v)
}
static void elemAt(EvalState & state, Value & list, int n, Value & v)
{
state.forceList(list);
if (n < 0 || n >= list.list.length)
throw Error(format("list index %1% is out of bounds") % n);
state.forceValue(*list.list.elems[n]);
v = *list.list.elems[n];
}
/* Return the n-1'th element of a list. */
static void prim_elemAt(EvalState & state, Value * * args, Value & v)
{
elemAt(state, *args[0], state.forceInt(*args[1]), v);
}
/* Return the first element of a list. */
static void prim_head(EvalState & state, Value * * args, Value & v)
{
state.forceList(*args[0]);
if (args[0]->list.length == 0)
throw Error("`head' called on an empty list");
state.forceValue(*args[0]->list.elems[0]);
v = *args[0]->list.elems[0];
elemAt(state, *args[0], 0, v);
}
/* Return a list consisting of everything but the the first element of
a list. */
a list. Warning: this function takes O(n) time, so you probably
don't want to use it! */
static void prim_tail(EvalState & state, Value * * args, Value & v)
{
state.forceList(*args[0]);
@ -911,6 +926,52 @@ static void prim_map(EvalState & state, Value * * args, Value & v)
}
/* Filter a list using a predicate; that is, return a list containing
every element from the list for which the predicate function
returns true. */
static void prim_filter(EvalState & state, Value * * args, Value & v)
{
state.forceFunction(*args[0]);
state.forceList(*args[1]);
// FIXME: putting this on the stack is risky.
Value * vs[args[1]->list.length];
unsigned int k = 0;
for (unsigned int n = 0; n < args[1]->list.length; ++n) {
Value res;
state.callFunction(*args[0], *args[1]->list.elems[n], res);
if (state.forceBool(res))
vs[k++] = args[1]->list.elems[n];
}
state.mkList(v, k);
for (unsigned int n = 0; n < k; ++n) v.list.elems[n] = vs[n];
}
/* Return true if a list contains a given element. */
static void prim_elem(EvalState & state, Value * * args, Value & v)
{
bool res = false;
state.forceList(*args[1]);
for (unsigned int n = 0; n < args[1]->list.length; ++n)
if (state.eqValues(*args[0], *args[1]->list.elems[n])) {
res = true;
break;
}
mkBool(v, res);
}
/* Concatenate a list of lists. */
static void prim_concatLists(EvalState & state, Value * * args, Value & v)
{
state.forceList(*args[0]);
state.concatLists(v, args[0]->list.length, args[0]->list.elems);
}
/* Return the length of a list. This is an O(1) time operation. */
static void prim_length(EvalState & state, Value * * args, Value & v)
{
@ -1122,11 +1183,15 @@ void EvalState::createBaseEnv()
// Lists
addPrimOp("__isList", 1, prim_isList);
addPrimOp("__elemAt", 2, prim_elemAt);
addPrimOp("__head", 1, prim_head);
addPrimOp("__tail", 1, prim_tail);
addPrimOp("map", 2, prim_map);
addPrimOp("__filter", 2, prim_filter);
addPrimOp("__elem", 2, prim_elem);
addPrimOp("__concatLists", 1, prim_concatLists);
addPrimOp("__length", 1, prim_length);
// Integer arithmetic
addPrimOp("__add", 2, prim_add);
addPrimOp("__sub", 2, prim_sub);