Add ‘seq’ primop

This commit is contained in:
Eelco Dolstra 2014-09-22 14:53:21 +02:00
parent eff120d1b9
commit a54c263402
4 changed files with 15 additions and 0 deletions

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@ -383,6 +383,15 @@ static void prim_getEnv(EvalState & state, const Pos & pos, Value * * args, Valu
} }
/* Evaluate the first argument, then return the second argument. */
void prim_seq(EvalState & state, const Pos & pos, Value * * args, Value & v)
{
state.forceValue(*args[0]);
state.forceValue(*args[1]);
v = *args[1];
}
/* Evaluate the first expression and print it on standard error. Then /* Evaluate the first expression and print it on standard error. Then
return the second expression. Useful for debugging. */ return the second expression. Useful for debugging. */
static void prim_trace(EvalState & state, const Pos & pos, Value * * args, Value & v) static void prim_trace(EvalState & state, const Pos & pos, Value * * args, Value & v)
@ -1424,6 +1433,9 @@ void EvalState::createBaseEnv()
addPrimOp("__tryEval", 1, prim_tryEval); addPrimOp("__tryEval", 1, prim_tryEval);
addPrimOp("__getEnv", 1, prim_getEnv); addPrimOp("__getEnv", 1, prim_getEnv);
// Strictness
addPrimOp("__seq", 2, prim_seq);
// Debugging // Debugging
addPrimOp("__trace", 2, prim_trace); addPrimOp("__trace", 2, prim_trace);
addPrimOp("__gcCanary", 1, prim_gcCanary); addPrimOp("__gcCanary", 1, prim_gcCanary);

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@ -0,0 +1 @@
builtins.seq (abort "foo") 2

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@ -0,0 +1 @@
2

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@ -0,0 +1 @@
builtins.seq 1 2