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rename SymbolIdx -> Symbol, Symbol -> SymbolStr

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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.
This commit is contained in:
pennae 2022-04-22 21:45:39 +02:00
parent 7f814d6d9a
commit a385e51a08
18 changed files with 171 additions and 159 deletions
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19
src/libexpr/nixexpr.cc
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@ -24,8 +24,10 @@ static void showString(std::ostream & str, std::string_view s)
str << '"';
}
static void showId(std::ostream & str, std::string_view s)
std::ostream & operator <<(std::ostream & str, const SymbolStr & symbol)
{
std::string_view s = symbol;
if (s.empty())
str << "\"\"";
else if (s == "if") // FIXME: handle other keywords
@ -34,7 +36,7 @@ static void showId(std::ostream & str, std::string_view s)
char c = s[0];
if (!((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_')) {
showString(str, s);
return;
return str;
}
for (auto c : s)
if (!((c >= 'a' && c <= 'z') ||
@ -42,15 +44,10 @@ static void showId(std::ostream & str, std::string_view s)
(c >= '0' && c <= '9') ||
c == '_' || c == '\'' || c == '-')) {
showString(str, s);
return;
return str;
}
str << s;
}
}
std::ostream & operator << (std::ostream & str, const Symbol & sym)
{
showId(str, sym.s);
return str;
}
@ -499,12 +496,12 @@ void ExprPos::bindVars(const EvalState & es, const StaticEnv & env)
/* Storing function names. */
void Expr::setName(SymbolIdx name)
void Expr::setName(Symbol name)
{
}
void ExprLambda::setName(SymbolIdx name)
void ExprLambda::setName(Symbol name)
{
this->name = name;
body->setName(name);
@ -526,7 +523,7 @@ std::string ExprLambda::showNamePos(const EvalState & state) const
size_t SymbolTable::totalSize() const
{
size_t n = 0;
dump([&] (const Symbol & s) { n += std::string_view(s).size(); });
dump([&] (const std::string & s) { n += s.size(); });
return n;
}