rename SymbolIdx -> Symbol, Symbol -> SymbolStr

after #6218 `Symbol` no longer confers a uniqueness invariant on the
string it wraps, it is now possible to create multiple symbols that
compare equal but whose string contents have different addresses. this
guarantee is now only provided by `SymbolIdx`, leaving `Symbol` only as
a string wrapper that knows about the intricacies of how symbols need to
be formatted for output.

this change renames `SymbolIdx` to `Symbol` to restore the previous
semantics of `Symbol` to that name. we also keep the wrapper type and
rename it to `SymbolStr` instead of returning plain strings from lookups
into the symbol table because symbols are formatted for output in many
places. theoretically we do not need `SymbolStr`, only a function that
formats a string for output as a symbol, but having to wrap every symbol
that appears in a message into eg `formatSymbol()` is error-prone and
inconvient.

1 files changed, 6 insertions, 6 deletions

diff --git a/src/libexpr/attr-set.hh b/src/libexpr/attr-set.hh
index 3bf23eeb2..31251efc4 100644
--- a/src/libexpr/attr-set.hh
+++ b/src/libexpr/attr-set.hh
@@ -19,10 +19,10 @@ struct Attr
        both of them are uint32 wrappers, they are next to each other
        to make sure that Attr has no padding on 64 bit machines. that
        way we keep Attr size at two words with no wasted space. */
-    SymbolIdx name;
+    Symbol name;
     PosIdx pos;
     Value * value;
-    Attr(SymbolIdx name, Value * value, PosIdx pos = noPos)
+    Attr(Symbol name, Value * value, PosIdx pos = noPos)
         : name(name), pos(pos), value(value) { };
     Attr() { };
     bool operator < (const Attr & a) const
@@ -66,7 +66,7 @@ public:
         attrs[size_++] = attr;
     }
 
-    iterator find(const SymbolIdx & name)
+    iterator find(const Symbol & name)
     {
         Attr key(name, 0);
         iterator i = std::lower_bound(begin(), end(), key);
@@ -74,7 +74,7 @@ public:
         return end();
     }
 
-    Attr * get(const SymbolIdx & name)
+    Attr * get(const Symbol & name)
     {
         Attr key(name, 0);
         iterator i = std::lower_bound(begin(), end(), key);
@@ -128,7 +128,7 @@ public:
         : bindings(bindings), state(state)
     { }
 
-    void insert(SymbolIdx name, Value * value, PosIdx pos = noPos)
+    void insert(Symbol name, Value * value, PosIdx pos = noPos)
     {
         insert(Attr(name, value, pos));
     }
@@ -143,7 +143,7 @@ public:
         bindings->push_back(attr);
     }
 
-    Value & alloc(const SymbolIdx & name, PosIdx pos = noPos);
+    Value & alloc(const Symbol & name, PosIdx pos = noPos);
 
     Value & alloc(std::string_view name, PosIdx pos = noPos);