Merge pull request #8576 from obsidiansystems/findPath-cleanup

Use a struct not `std::pair` for `SearchPathElem`

3 files changed, 30 insertions, 20 deletions

diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh
index 8e41bdbd0..7b726a78f 100644
--- a/src/libexpr/eval.hh
+++ b/src/libexpr/eval.hh
@@ -65,8 +65,12 @@ std::string printValue(const EvalState & state, const Value & v);
 std::ostream & operator << (std::ostream & os, const ValueType t);
 
 
-// FIXME: maybe change this to an std::variant<SourcePath, URL>.
-typedef std::pair<std::string, std::string> SearchPathElem;
+struct SearchPathElem
+{
+    std::string prefix;
+    // FIXME: maybe change this to an std::variant<SourcePath, URL>.
+    std::string path;
+};
 typedef std::list<SearchPathElem> SearchPath;
 
 
diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y
index 5c9597f8a..03e6fb02c 100644
--- a/src/libexpr/parser.y
+++ b/src/libexpr/parser.y
@@ -741,7 +741,10 @@ void EvalState::addToSearchPath(const std::string & s)
         path = std::string(s, pos + 1);
     }
 
-    searchPath.emplace_back(prefix, path);
+    searchPath.emplace_back(SearchPathElem {
+        .prefix = prefix,
+        .path = path,
+    });
 }
 
 
@@ -755,11 +758,11 @@ SourcePath EvalState::findFile(SearchPath & searchPath, const std::string_view p
 {
     for (auto & i : searchPath) {
         std::string suffix;
-        if (i.first.empty())
+        if (i.prefix.empty())
             suffix = concatStrings("/", path);
         else {
-            auto s = i.first.size();
-            if (path.compare(0, s, i.first) != 0 ||
+            auto s = i.prefix.size();
+            if (path.compare(0, s, i.prefix) != 0 ||
                 (path.size() > s && path[s] != '/'))
                 continue;
             suffix = path.size() == s ? "" : concatStrings("/", path.substr(s));
@@ -785,47 +788,47 @@ SourcePath EvalState::findFile(SearchPath & searchPath, const std::string_view p
 
 std::pair<bool, std::string> EvalState::resolveSearchPathElem(const SearchPathElem & elem)
 {
-    auto i = searchPathResolved.find(elem.second);
+    auto i = searchPathResolved.find(elem.path);
     if (i != searchPathResolved.end()) return i->second;
 
     std::pair<bool, std::string> res;
 
-    if (EvalSettings::isPseudoUrl(elem.second)) {
+    if (EvalSettings::isPseudoUrl(elem.path)) {
         try {
             auto storePath = fetchers::downloadTarball(
-                store, EvalSettings::resolvePseudoUrl(elem.second), "source", false).tree.storePath;
+                store, EvalSettings::resolvePseudoUrl(elem.path), "source", false).tree.storePath;
             res = { true, store->toRealPath(storePath) };
         } catch (FileTransferError & e) {
             logWarning({
-                .msg = hintfmt("Nix search path entry '%1%' cannot be downloaded, ignoring", elem.second)
+                .msg = hintfmt("Nix search path entry '%1%' cannot be downloaded, ignoring", elem.path)
             });
             res = { false, "" };
         }
     }
 
-    else if (hasPrefix(elem.second, "flake:")) {
+    else if (hasPrefix(elem.path, "flake:")) {
         experimentalFeatureSettings.require(Xp::Flakes);
-        auto flakeRef = parseFlakeRef(elem.second.substr(6), {}, true, false);
-        debug("fetching flake search path element '%s''", elem.second);
+        auto flakeRef = parseFlakeRef(elem.path.substr(6), {}, true, false);
+        debug("fetching flake search path element '%s''", elem.path);
         auto storePath = flakeRef.resolve(store).fetchTree(store).first.storePath;
         res = { true, store->toRealPath(storePath) };
     }
 
     else {
-        auto path = absPath(elem.second);
+        auto path = absPath(elem.path);
         if (pathExists(path))
             res = { true, path };
         else {
             logWarning({
-                .msg = hintfmt("Nix search path entry '%1%' does not exist, ignoring", elem.second)
+                .msg = hintfmt("Nix search path entry '%1%' does not exist, ignoring", elem.path)
             });
             res = { false, "" };
         }
     }
 
-    debug("resolved search path element '%s' to '%s'", elem.second, res.second);
+    debug("resolved search path element '%s' to '%s'", elem.path, res.second);
 
-    searchPathResolved[elem.second] = res;
+    searchPathResolved[elem.path] = res;
     return res;
 }
 
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 5b2f7e8b7..9dd7bae02 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -1656,7 +1656,10 @@ static void prim_findFile(EvalState & state, const PosIdx pos, Value * * args, V
             }));
         }
 
-        searchPath.emplace_back(prefix, path);
+        searchPath.emplace_back(SearchPathElem {
+            .prefix = prefix,
+            .path = path,
+        });
     }
 
     auto path = state.forceStringNoCtx(*args[1], pos, "while evaluating the second argument passed to builtins.findFile");
@@ -4129,8 +4132,8 @@ void EvalState::createBaseEnv()
     int n = 0;
     for (auto & i : searchPath) {
         auto attrs = buildBindings(2);
-        attrs.alloc("path").mkString(i.second);
-        attrs.alloc("prefix").mkString(i.first);
+        attrs.alloc("path").mkString(i.path);
+        attrs.alloc("prefix").mkString(i.prefix);
         (v.listElems()[n++] = allocValue())->mkAttrs(attrs);
     }
     addConstant("__nixPath", v);