From b6c8e57056f81fa3c2827a7fdc6f335ec54727bd Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Wed, 24 Nov 2021 20:21:34 +0100 Subject: [PATCH] Support range-based for loop over list values --- src/libexpr/eval.cc | 18 ++++---- src/libexpr/flake/flake.cc | 3 +- src/libexpr/get-drvs.cc | 22 ++++----- src/libexpr/primops.cc | 82 ++++++++++++++++------------------ src/libexpr/primops/context.cc | 7 ++- src/libexpr/value-to-json.cc | 4 +- src/libexpr/value-to-xml.cc | 4 +- src/libexpr/value.hh | 30 +++++++++++++ src/nix-env/nix-env.cc | 6 +-- src/nix/repl.cc | 6 +-- 10 files changed, 103 insertions(+), 79 deletions(-) diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 97fc04711..5adac87cd 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -119,8 +119,8 @@ void printValue(std::ostream & str, std::set & active, const Valu case tList2: case tListN: str << "[ "; - for (unsigned int n = 0; n < v.listSize(); ++n) { - printValue(str, active, *v.listElems()[n]); + for (auto v2 : v.listItems()) { + printValue(str, active, *v2); str << " "; } str << "]"; @@ -1151,8 +1151,8 @@ void ExprLet::eval(EvalState & state, Env & env, Value & v) void ExprList::eval(EvalState & state, Env & env, Value & v) { state.mkList(v, elems.size()); - for (size_t n = 0; n < elems.size(); ++n) - v.listElems()[n] = elems[n]->maybeThunk(state, env); + for (auto [n, v2] : enumerate(v.listItems())) + const_cast(v2) = elems[n]->maybeThunk(state, env); } @@ -1732,8 +1732,8 @@ void EvalState::forceValueDeep(Value & v) } else if (v.isList()) { - for (size_t n = 0; n < v.listSize(); ++n) - recurse(*v.listElems()[n]); + for (auto v2 : v.listItems()) + recurse(*v2); } }; @@ -1917,12 +1917,12 @@ string EvalState::coerceToString(const Pos & pos, Value & v, PathSet & context, if (v.isList()) { string result; - for (size_t n = 0; n < v.listSize(); ++n) { - result += coerceToString(pos, *v.listElems()[n], + for (auto [n, v2] : enumerate(v.listItems())) { + result += coerceToString(pos, *v2, context, coerceMore, copyToStore); if (n < v.listSize() - 1 /* !!! not quite correct */ - && (!v.listElems()[n]->isList() || v.listElems()[n]->listSize() != 0)) + && (!v2->isList() || v2->listSize() != 0)) result += " "; } return result; diff --git a/src/libexpr/flake/flake.cc b/src/libexpr/flake/flake.cc index f5be67d67..06136579e 100644 --- a/src/libexpr/flake/flake.cc +++ b/src/libexpr/flake/flake.cc @@ -257,8 +257,7 @@ static Flake getFlake( flake.config.settings.insert({setting.name, state.forceBool(*setting.value, *setting.pos)}); else if (setting.value->type() == nList) { std::vector ss; - for (unsigned int n = 0; n < setting.value->listSize(); ++n) { - auto elem = setting.value->listElems()[n]; + for (auto elem : setting.value->listItems()) { if (elem->type() != nString) throw TypeError("list element in flake configuration setting '%s' is %s while a string is expected", setting.name, showType(*setting.value)); diff --git a/src/libexpr/get-drvs.cc b/src/libexpr/get-drvs.cc index f774e6493..ed4c47fbb 100644 --- a/src/libexpr/get-drvs.cc +++ b/src/libexpr/get-drvs.cc @@ -102,9 +102,9 @@ DrvInfo::Outputs DrvInfo::queryOutputs(bool onlyOutputsToInstall) state->forceList(*i->value, *i->pos); /* For each output... */ - for (unsigned int j = 0; j < i->value->listSize(); ++j) { + for (auto elem : i->value->listItems()) { /* Evaluate the corresponding set. */ - string name = state->forceStringNoCtx(*i->value->listElems()[j], *i->pos); + string name = state->forceStringNoCtx(*elem, *i->pos); Bindings::iterator out = attrs->find(state->symbols.create(name)); if (out == attrs->end()) continue; // FIXME: throw error? state->forceAttrs(*out->value); @@ -128,9 +128,9 @@ DrvInfo::Outputs DrvInfo::queryOutputs(bool onlyOutputsToInstall) /* ^ this shows during `nix-env -i` right under the bad derivation */ if (!outTI->isList()) throw errMsg; Outputs result; - for (auto i = outTI->listElems(); i != outTI->listElems() + outTI->listSize(); ++i) { - if ((*i)->type() != nString) throw errMsg; - auto out = outputs.find((*i)->string.s); + for (auto elem : outTI->listItems()) { + if (elem->type() != nString) throw errMsg; + auto out = outputs.find(elem->string.s); if (out == outputs.end()) throw errMsg; result.insert(*out); } @@ -174,8 +174,8 @@ bool DrvInfo::checkMeta(Value & v) { state->forceValue(v); if (v.type() == nList) { - for (unsigned int n = 0; n < v.listSize(); ++n) - if (!checkMeta(*v.listElems()[n])) return false; + for (auto elem : v.listItems()) + if (!checkMeta(*elem)) return false; return true; } else if (v.type() == nAttrs) { @@ -364,10 +364,10 @@ static void getDerivations(EvalState & state, Value & vIn, } else if (v.type() == nList) { - for (unsigned int n = 0; n < v.listSize(); ++n) { - string pathPrefix2 = addToPath(pathPrefix, (format("%1%") % n).str()); - if (getDerivation(state, *v.listElems()[n], pathPrefix2, drvs, done, ignoreAssertionFailures)) - getDerivations(state, *v.listElems()[n], pathPrefix2, autoArgs, drvs, done, ignoreAssertionFailures); + for (auto [n, elem] : enumerate(v.listItems())) { + string pathPrefix2 = addToPath(pathPrefix, fmt("%d", n)); + if (getDerivation(state, *elem, pathPrefix2, drvs, done, ignoreAssertionFailures)) + getDerivations(state, *elem, pathPrefix2, autoArgs, drvs, done, ignoreAssertionFailures); } } diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index 8cbeaa520..c0d59da8c 100644 --- a/src/libexpr/primops.cc +++ b/src/libexpr/primops.cc @@ -335,9 +335,8 @@ void prim_exec(EvalState & state, const Pos & pos, Value * * args, Value & v) PathSet context; auto program = state.coerceToString(pos, *elems[0], context, false, false); Strings commandArgs; - for (unsigned int i = 1; i < args[0]->listSize(); ++i) { + for (unsigned int i = 1; i < args[0]->listSize(); ++i) commandArgs.emplace_back(state.coerceToString(pos, *elems[i], context, false, false)); - } try { state.realiseContext(context); } catch (InvalidPathError & e) { @@ -616,8 +615,8 @@ static void prim_genericClosure(EvalState & state, const Pos & pos, Value * * ar state.forceList(*startSet->value, pos); ValueList workSet; - for (unsigned int n = 0; n < startSet->value->listSize(); ++n) - workSet.push_back(startSet->value->listElems()[n]); + for (auto elem : startSet->value->listItems()) + workSet.push_back(elem); /* Get the operator. */ Bindings::iterator op = getAttr( @@ -662,9 +661,9 @@ static void prim_genericClosure(EvalState & state, const Pos & pos, Value * * ar state.forceList(call, pos); /* Add the values returned by the operator to the work set. */ - for (unsigned int n = 0; n < call.listSize(); ++n) { - state.forceValue(*call.listElems()[n], pos); - workSet.push_back(call.listElems()[n]); + for (auto elem : call.listItems()) { + state.forceValue(*elem, pos); + workSet.push_back(elem); } } @@ -1013,8 +1012,8 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * * command-line arguments to the builder. */ else if (i->name == state.sArgs) { state.forceList(*i->value, pos); - for (unsigned int n = 0; n < i->value->listSize(); ++n) { - string s = state.coerceToString(posDrvName, *i->value->listElems()[n], context, true); + for (auto elem : i->value->listItems()) { + string s = state.coerceToString(posDrvName, *elem, context, true); drv.args.push_back(s); } } @@ -1044,8 +1043,8 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * * /* Require ‘outputs’ to be a list of strings. */ state.forceList(*i->value, posDrvName); Strings ss; - for (unsigned int n = 0; n < i->value->listSize(); ++n) - ss.emplace_back(state.forceStringNoCtx(*i->value->listElems()[n], posDrvName)); + for (auto elem : i->value->listItems()) + ss.emplace_back(state.forceStringNoCtx(*elem, posDrvName)); handleOutputs(ss); } @@ -1460,20 +1459,19 @@ static void prim_findFile(EvalState & state, const Pos & pos, Value * * args, Va SearchPath searchPath; - for (unsigned int n = 0; n < args[0]->listSize(); ++n) { - Value & v2(*args[0]->listElems()[n]); - state.forceAttrs(v2, pos); + for (auto v2 : args[0]->listItems()) { + state.forceAttrs(*v2, pos); string prefix; - Bindings::iterator i = v2.attrs->find(state.symbols.create("prefix")); - if (i != v2.attrs->end()) + Bindings::iterator i = v2->attrs->find(state.symbols.create("prefix")); + if (i != v2->attrs->end()) prefix = state.forceStringNoCtx(*i->value, pos); i = getAttr( state, "findFile", "path", - v2.attrs, + v2->attrs, pos ); @@ -2239,9 +2237,9 @@ static void prim_removeAttrs(EvalState & state, const Pos & pos, Value * * args, /* Get the attribute names to be removed. */ std::set names; - for (unsigned int i = 0; i < args[1]->listSize(); ++i) { - state.forceStringNoCtx(*args[1]->listElems()[i], pos); - names.insert(state.symbols.create(args[1]->listElems()[i]->string.s)); + for (auto elem : args[1]->listItems()) { + state.forceStringNoCtx(*elem, pos); + names.insert(state.symbols.create(elem->string.s)); } /* Copy all attributes not in that set. Note that we don't need @@ -2249,7 +2247,7 @@ static void prim_removeAttrs(EvalState & state, const Pos & pos, Value * * args, vector. */ state.mkAttrs(v, args[0]->attrs->size()); for (auto & i : *args[0]->attrs) { - if (names.find(i.name) == names.end()) + if (!names.count(i.name)) v.attrs->push_back(i); } } @@ -2283,15 +2281,14 @@ static void prim_listToAttrs(EvalState & state, const Pos & pos, Value * * args, std::set seen; - for (unsigned int i = 0; i < args[0]->listSize(); ++i) { - Value & v2(*args[0]->listElems()[i]); - state.forceAttrs(v2, pos); + for (auto v2 : args[0]->listItems()) { + state.forceAttrs(*v2, pos); Bindings::iterator j = getAttr( state, "listToAttrs", state.sName, - v2.attrs, + v2->attrs, pos ); @@ -2303,7 +2300,7 @@ static void prim_listToAttrs(EvalState & state, const Pos & pos, Value * * args, state, "listToAttrs", state.sValue, - v2.attrs, + v2->attrs, pos ); v.attrs->push_back(Attr(sym, j2->value, j2->pos)); @@ -2370,11 +2367,10 @@ static void prim_catAttrs(EvalState & state, const Pos & pos, Value * * args, Va Value * res[args[1]->listSize()]; unsigned int found = 0; - for (unsigned int n = 0; n < args[1]->listSize(); ++n) { - Value & v2(*args[1]->listElems()[n]); - state.forceAttrs(v2, pos); - Bindings::iterator i = v2.attrs->find(attrName); - if (i != v2.attrs->end()) + for (auto v2 : args[1]->listItems()) { + state.forceAttrs(*v2, pos); + Bindings::iterator i = v2->attrs->find(attrName); + if (i != v2->attrs->end()) res[found++] = i->value; } @@ -2649,8 +2645,8 @@ static void prim_elem(EvalState & state, const Pos & pos, Value * * args, Value { bool res = false; state.forceList(*args[1], pos); - for (unsigned int n = 0; n < args[1]->listSize(); ++n) - if (state.eqValues(*args[0], *args[1]->listElems()[n])) { + for (auto elem : args[1]->listItems()) + if (state.eqValues(*args[0], *elem)) { res = true; break; } @@ -2709,8 +2705,8 @@ static void prim_foldlStrict(EvalState & state, const Pos & pos, Value * * args, if (args[2]->listSize()) { Value * vCur = args[1]; - for (unsigned int n = 0; n < args[2]->listSize(); ++n) { - Value * vs []{vCur, args[2]->listElems()[n]}; + for (auto [n, elem] : enumerate(args[2]->listItems())) { + Value * vs []{vCur, elem}; vCur = n == args[2]->listSize() - 1 ? &v : state.allocValue(); state.callFunction(*args[0], 2, vs, *vCur, pos); } @@ -2740,8 +2736,8 @@ static void anyOrAll(bool any, EvalState & state, const Pos & pos, Value * * arg state.forceList(*args[1], pos); Value vTmp; - for (unsigned int n = 0; n < args[1]->listSize(); ++n) { - state.callFunction(*args[0], *args[1]->listElems()[n], vTmp, pos); + for (auto elem : args[1]->listItems()) { + state.callFunction(*args[0], *elem, vTmp, pos); bool res = state.forceBool(vTmp, pos); if (res == any) { mkBool(v, any); @@ -3470,9 +3466,9 @@ static void prim_concatStringsSep(EvalState & state, const Pos & pos, Value * * res.reserve((args[1]->listSize() + 32) * sep.size()); bool first = true; - for (unsigned int n = 0; n < args[1]->listSize(); ++n) { + for (auto elem : args[1]->listItems()) { if (first) first = false; else res += sep; - res += state.coerceToString(pos, *args[1]->listElems()[n], context); + res += state.coerceToString(pos, *elem, context); } mkString(v, res, context); @@ -3501,14 +3497,14 @@ static void prim_replaceStrings(EvalState & state, const Pos & pos, Value * * ar vector from; from.reserve(args[0]->listSize()); - for (unsigned int n = 0; n < args[0]->listSize(); ++n) - from.push_back(state.forceString(*args[0]->listElems()[n], pos)); + for (auto elem : args[0]->listItems()) + from.push_back(state.forceString(*elem, pos)); vector> to; to.reserve(args[1]->listSize()); - for (unsigned int n = 0; n < args[1]->listSize(); ++n) { + for (auto elem : args[1]->listItems()) { PathSet ctx; - auto s = state.forceString(*args[1]->listElems()[n], ctx, pos); + auto s = state.forceString(*elem, ctx, pos); to.push_back(std::make_pair(std::move(s), std::move(ctx))); } diff --git a/src/libexpr/primops/context.cc b/src/libexpr/primops/context.cc index 31cf812b4..20545afd0 100644 --- a/src/libexpr/primops/context.cc +++ b/src/libexpr/primops/context.cc @@ -118,9 +118,8 @@ static void prim_getContext(EvalState & state, const Pos & pos, Value * * args, auto & outputsVal = *state.allocAttr(infoVal, state.sOutputs); state.mkList(outputsVal, info.second.outputs.size()); size_t i = 0; - for (const auto & output : info.second.outputs) { + for (const auto & output : info.second.outputs) mkString(*(outputsVal.listElems()[i++] = state.allocValue()), output); - } } infoVal.attrs->sort(); } @@ -181,8 +180,8 @@ static void prim_appendContext(EvalState & state, const Pos & pos, Value * * arg .errPos = *i.pos }); } - for (unsigned int n = 0; n < iter->value->listSize(); ++n) { - auto name = state.forceStringNoCtx(*iter->value->listElems()[n], *iter->pos); + for (auto elem : iter->value->listItems()) { + auto name = state.forceStringNoCtx(*elem, *iter->pos); context.insert("!" + name + "!" + string(i.name)); } } diff --git a/src/libexpr/value-to-json.cc b/src/libexpr/value-to-json.cc index 4d642c720..517da4c01 100644 --- a/src/libexpr/value-to-json.cc +++ b/src/libexpr/value-to-json.cc @@ -63,9 +63,9 @@ void printValueAsJSON(EvalState & state, bool strict, case nList: { auto list(out.list()); - for (unsigned int n = 0; n < v.listSize(); ++n) { + for (auto elem : v.listItems()) { auto placeholder(list.placeholder()); - printValueAsJSON(state, strict, *v.listElems()[n], pos, placeholder, context); + printValueAsJSON(state, strict, *elem, pos, placeholder, context); } break; } diff --git a/src/libexpr/value-to-xml.cc b/src/libexpr/value-to-xml.cc index 54268ece0..a875f82d7 100644 --- a/src/libexpr/value-to-xml.cc +++ b/src/libexpr/value-to-xml.cc @@ -122,8 +122,8 @@ static void printValueAsXML(EvalState & state, bool strict, bool location, case nList: { XMLOpenElement _(doc, "list"); - for (unsigned int n = 0; n < v.listSize(); ++n) - printValueAsXML(state, strict, location, *v.listElems()[n], doc, context, drvsSeen, pos); + for (auto v2 : v.listItems()) + printValueAsXML(state, strict, location, *v2, doc, context, drvsSeen, pos); break; } diff --git a/src/libexpr/value.hh b/src/libexpr/value.hh index 3bb97b3c2..4b43e47ae 100644 --- a/src/libexpr/value.hh +++ b/src/libexpr/value.hh @@ -1,5 +1,7 @@ #pragma once +#include + #include "symbol-table.hh" #if HAVE_BOEHMGC @@ -350,6 +352,34 @@ public: bool isTrivial() const; std::vector> getContext(); + + auto listItems() + { + struct ListIterable + { + typedef Value * const * iterator; + iterator _begin, _end; + iterator begin() const { return _begin; } + iterator end() const { return _end; } + }; + assert(isList()); + auto begin = listElems(); + return ListIterable { begin, begin + listSize() }; + } + + auto listItems() const + { + struct ConstListIterable + { + typedef const Value * const * iterator; + iterator _begin, _end; + iterator begin() const { return _begin; } + iterator end() const { return _end; } + }; + assert(isList()); + auto begin = listElems(); + return ConstListIterable { begin, begin + listSize() }; + } }; diff --git a/src/nix-env/nix-env.cc b/src/nix-env/nix-env.cc index 4056d973d..0dd0e34a0 100644 --- a/src/nix-env/nix-env.cc +++ b/src/nix-env/nix-env.cc @@ -1149,10 +1149,10 @@ static void opQuery(Globals & globals, Strings opFlags, Strings opArgs) } else if (v->type() == nList) { attrs2["type"] = "strings"; XMLOpenElement m(xml, "meta", attrs2); - for (unsigned int j = 0; j < v->listSize(); ++j) { - if (v->listElems()[j]->type() != nString) continue; + for (auto elem : v->listItems()) { + if (elem->type() != nString) continue; XMLAttrs attrs3; - attrs3["value"] = v->listElems()[j]->string.s; + attrs3["value"] = elem->string.s; xml.writeEmptyElement("string", attrs3); } } else if (v->type() == nAttrs) { diff --git a/src/nix/repl.cc b/src/nix/repl.cc index fd86174f2..41283c5f2 100644 --- a/src/nix/repl.cc +++ b/src/nix/repl.cc @@ -771,12 +771,12 @@ std::ostream & NixRepl::printValue(std::ostream & str, Value & v, unsigned int m str << "[ "; if (maxDepth > 0) - for (unsigned int n = 0; n < v.listSize(); ++n) { - if (seen.find(v.listElems()[n]) != seen.end()) + for (auto elem : v.listItems()) { + if (seen.count(elem)) str << "«repeated»"; else try { - printValue(str, *v.listElems()[n], maxDepth - 1, seen); + printValue(str, *elem, maxDepth - 1, seen); } catch (AssertionError & e) { str << ANSI_RED "«error: " << e.msg() << "»" ANSI_NORMAL; }