diff options
Diffstat (limited to 'src/libexpr')
-rw-r--r-- | src/libexpr/eval-test.cc | 2 | ||||
-rw-r--r-- | src/libexpr/eval.cc | 210 | ||||
-rw-r--r-- | src/libexpr/eval.hh | 13 | ||||
-rw-r--r-- | src/libexpr/primops.cc | 22 |
4 files changed, 139 insertions, 108 deletions
diff --git a/src/libexpr/eval-test.cc b/src/libexpr/eval-test.cc index 8aade1298f3d..0b20883a33d4 100644 --- a/src/libexpr/eval-test.cc +++ b/src/libexpr/eval-test.cc @@ -68,6 +68,8 @@ void run(Strings args) doTest("let x = x; in if true || x then 1 else 2"); doTest("/etc/passwd"); doTest("import ./foo.nix"); + doTest("map (x: __add 1 x) [ 1 2 3 ]"); + doTest("map (__add 1) [ 1 2 3 ]"); } diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 86484031b1e5..f1437e465709 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -328,106 +328,9 @@ void EvalState::eval(Env & env, Expr e, Value & v) Expr fun, arg; if (matchCall(e, fun, arg)) { eval(env, fun, v); - - if (v.type == tPrimOp || v.type == tPrimOpApp) { - unsigned int argsLeft = - v.type == tPrimOp ? v.primOp.arity : v.primOpApp.argsLeft; - if (argsLeft == 1) { - /* We have all the arguments, so call the primop. - First find the primop. */ - Value * primOp = &v; - while (primOp->type == tPrimOpApp) primOp = primOp->primOpApp.left; - assert(primOp->type == tPrimOp); - unsigned int arity = primOp->primOp.arity; - - Value vLastArg; - mkThunk(vLastArg, env, arg); - - /* Put all the arguments in an array. */ - Value * vArgs[arity]; - unsigned int n = arity - 1; - vArgs[n--] = &vLastArg; - for (Value * arg = &v; arg->type == tPrimOpApp; arg = arg->primOpApp.left) - vArgs[n--] = arg->primOpApp.right; - - /* And call the primop. */ - primOp->primOp.fun(*this, vArgs, v); - } else { - Value * v2 = allocValues(2); - v2[0] = v; - mkThunk(v2[1], env, arg); - v.type = tPrimOpApp; - v.primOpApp.left = &v2[0]; - v.primOpApp.right = &v2[1]; - v.primOpApp.argsLeft = argsLeft - 1; - } - return; - } - - if (v.type != tLambda) throw TypeError("expected function"); - - Env & env2(allocEnv()); - env2.up = &env; - - ATermList formals; ATerm ellipsis; - - if (matchVarPat(v.lambda.pat, name)) { - Value & vArg = env2.bindings[name]; - nrValues++; - mkThunk(vArg, env, arg); - } - - else if (matchAttrsPat(v.lambda.pat, formals, ellipsis, name)) { - Value * vArg; - Value vArg_; - - if (name == sNoAlias) - vArg = &vArg_; - else { - vArg = &env2.bindings[name]; - nrValues++; - } - - eval(env, arg, *vArg); - forceAttrs(*vArg); - - /* For each formal argument, get the actual argument. If - there is no matching actual argument but the formal - argument has a default, use the default. */ - unsigned int attrsUsed = 0; - for (ATermIterator i(formals); i; ++i) { - Expr def; Sym name; - DefaultValue def2; - if (!matchFormal(*i, name, def2)) abort(); /* can't happen */ - - Bindings::iterator j = vArg->attrs->find(name); - - Value & v = env2.bindings[name]; - nrValues++; - - if (j == vArg->attrs->end()) { - if (!matchDefaultValue(def2, def)) def = 0; - if (def == 0) throw TypeError(format("the argument named `%1%' required by the function is missing") - % aterm2String(name)); - mkThunk(v, env2, def); - } else { - attrsUsed++; - v.type = tCopy; - v.val = &j->second; - } - } - - /* Check that each actual argument is listed as a formal - argument (unless the attribute match specifies a - `...'). TODO: show the names of the - expected/unexpected arguments. */ - if (ellipsis == eFalse && attrsUsed != vArg->attrs->size()) - throw TypeError("function called with unexpected argument"); - } - - else abort(); - - eval(env2, v.lambda.body, v); + Value vArg; + mkThunk(vArg, env, arg); // !!! should this be on the heap? + callFunction(v, vArg, v); return; } @@ -519,6 +422,103 @@ void EvalState::eval(Env & env, Expr e, Value & v) } +void EvalState::callFunction(Value & fun, Value & arg, Value & v) +{ + if (fun.type == tPrimOp || fun.type == tPrimOpApp) { + unsigned int argsLeft = + fun.type == tPrimOp ? fun.primOp.arity : fun.primOpApp.argsLeft; + if (argsLeft == 1) { + /* We have all the arguments, so call the primop. First + find the primop. */ + Value * primOp = &fun; + while (primOp->type == tPrimOpApp) primOp = primOp->primOpApp.left; + assert(primOp->type == tPrimOp); + unsigned int arity = primOp->primOp.arity; + + /* Put all the arguments in an array. */ + Value * vArgs[arity]; + unsigned int n = arity - 1; + vArgs[n--] = &arg; + for (Value * arg = &fun; arg->type == tPrimOpApp; arg = arg->primOpApp.left) + vArgs[n--] = arg->primOpApp.right; + + /* And call the primop. */ + primOp->primOp.fun(*this, vArgs, v); + } else { + Value * v2 = allocValues(2); + v2[0] = fun; + v2[1] = arg; + v.type = tPrimOpApp; + v.primOpApp.left = &v2[0]; + v.primOpApp.right = &v2[1]; + v.primOpApp.argsLeft = argsLeft - 1; + } + return; + } + + if (fun.type != tLambda) + throwTypeError("attempt to call something which is neither a function nor a primop (built-in operation) but %1%", + showType(fun)); + + Env & env2(allocEnv()); + env2.up = fun.lambda.env; + + ATermList formals; ATerm ellipsis, name; + + if (matchVarPat(fun.lambda.pat, name)) { + Value & vArg = env2.bindings[name]; + nrValues++; + vArg = arg; + } + + else if (matchAttrsPat(fun.lambda.pat, formals, ellipsis, name)) { + forceAttrs(arg); + + if (name != sNoAlias) { + env2.bindings[name] = arg; + nrValues++; + } + + /* For each formal argument, get the actual argument. If + there is no matching actual argument but the formal + argument has a default, use the default. */ + unsigned int attrsUsed = 0; + for (ATermIterator i(formals); i; ++i) { + Expr def; Sym name; + DefaultValue def2; + if (!matchFormal(*i, name, def2)) abort(); /* can't happen */ + + Bindings::iterator j = arg.attrs->find(name); + + Value & v = env2.bindings[name]; + nrValues++; + + if (j == arg.attrs->end()) { + if (!matchDefaultValue(def2, def)) def = 0; + if (def == 0) throw TypeError(format("the argument named `%1%' required by the function is missing") + % aterm2String(name)); + mkThunk(v, env2, def); + } else { + attrsUsed++; + v.type = tCopy; + v.val = &j->second; + } + } + + /* Check that each actual argument is listed as a formal + argument (unless the attribute match specifies a `...'). + TODO: show the names of the expected/unexpected + arguments. */ + if (ellipsis == eFalse && attrsUsed != arg.attrs->size()) + throw TypeError("function called with unexpected argument"); + } + + else abort(); + + eval(env2, fun.lambda.body, v); +} + + void EvalState::eval(Expr e, Value & v) { eval(baseEnv, e, v); @@ -567,6 +567,8 @@ void EvalState::forceValue(Value & v) forceValue(*v.val); v = *v.val; } + else if (v.type == tApp) + callFunction(*v.app.left, *v.app.right, v); else if (v.type == tBlackhole) throw EvalError("infinite recursion encountered"); } @@ -597,6 +599,14 @@ void EvalState::forceList(Value & v) } +void EvalState::forceFunction(Value & v) +{ + forceValue(v); + if (v.type != tLambda && v.type != tPrimOp && v.type != tPrimOpApp) + throw TypeError(format("value is %1% while a function was expected") % showType(v)); +} + + string EvalState::coerceToString(Value & v, PathSet & context, bool coerceMore, bool copyToStore) { diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh index 4706602d59fa..385c2d78da5b 100644 --- a/src/libexpr/eval.hh +++ b/src/libexpr/eval.hh @@ -36,6 +36,7 @@ typedef enum { tAttrs, tList, tThunk, + tApp, tLambda, tCopy, tBlackhole, @@ -69,6 +70,9 @@ struct Value Expr expr; } thunk; struct { + Value * left, * right; + } app; + struct { Env * env; Pattern pat; Expr body; @@ -161,13 +165,16 @@ struct EvalState void strictEval(Env & env, Expr e, Value & v); /* If `v' is a thunk, enter it and overwrite `v' with the result - of the evaluation of the thunk. Otherwise, this is a no-op. */ + of the evaluation of the thunk. If `v' is a delayed function + application, call the function and overwrite `v' with the + result. Otherwise, this is a no-op. */ void forceValue(Value & v); /* Force `v', and then verify that it has the expected type. */ int forceInt(Value & v); void forceAttrs(Value & v); void forceList(Value & v); + void forceFunction(Value & v); // either lambda or primop /* String coercion. Converts strings, paths and derivations to a string. If `coerceMore' is set, also converts nulls, integers, @@ -196,6 +203,10 @@ private: elements and attributes are compared recursively. */ bool eqValues(Value & v1, Value & v2); + void callFunction(Value & fun, Value & arg, Value & v); + +public: + /* Allocation primitives. */ Value * allocValues(unsigned int count); Env & allocEnv(); diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index 2815567e5d15..bf8271b130d9 100644 --- a/src/libexpr/primops.cc +++ b/src/libexpr/primops.cc @@ -913,22 +913,28 @@ static Expr prim_tail(EvalState & state, const ATermVector & args) throw Error("`tail' called on an empty list"); return makeList(ATgetNext(list)); } +#endif /* Apply a function to every element of a list. */ -static Expr prim_map(EvalState & state, const ATermVector & args) +static void prim_map(EvalState & state, Value * * args, Value & v) { - Expr fun = evalExpr(state, args[0]); - ATermList list = evalList(state, args[1]); + state.forceFunction(*args[0]); + state.forceList(*args[1]); - ATermList res = ATempty; - for (ATermIterator i(list); i; ++i) - res = ATinsert(res, makeCall(fun, *i)); + v.type = tList; + v.list.length = args[1]->list.length; + v.list.elems = state.allocValues(v.list.length); - return makeList(ATreverse(res)); + for (unsigned int n = 0; n < v.list.length; ++n) { + v.list.elems[n].type = tApp; + v.list.elems[n].app.left = args[0]; + v.list.elems[n].app.right = &args[1]->list.elems[n]; + } } +#if 0 /* Return the length of a list. This is an O(1) time operation. */ static Expr prim_length(EvalState & state, const ATermVector & args) { @@ -1189,7 +1195,9 @@ void EvalState::createBaseEnv() addPrimOp("__head", 1, prim_head); #if 0 addPrimOp("__tail", 1, prim_tail); +#endif addPrimOp("map", 2, prim_map); +#if 0 addPrimOp("__length", 1, prim_length); #endif |