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authorRobert Hensing <robert@roberthensing.nl>2023-04-16 14:07:35 +0200
committerRobert Hensing <robert@roberthensing.nl>2023-04-16 14:07:35 +0200
commitb6125772d7d5f82d48873fc93a7f261832154b14 (patch)
tree2700c6ab861df273c949739d06d6b1e6745d1819 /src
parent28a5cdde02964306e7eb443f696c8d5d59ebf9e9 (diff)
libexpr: Move identifier-like printing to print.cc
Diffstat (limited to 'src')
-rw-r--r--src/libcmd/repl.cc6
-rw-r--r--src/libexpr/nixexpr.cc27
-rw-r--r--src/libexpr/print.cc50
-rw-r--r--src/libexpr/print.hh18
4 files changed, 73 insertions, 28 deletions
diff --git a/src/libcmd/repl.cc b/src/libcmd/repl.cc
index 806dce024..80c08bf1c 100644
--- a/src/libcmd/repl.cc
+++ b/src/libcmd/repl.cc
@@ -426,6 +426,7 @@ StringSet NixRepl::completePrefix(const std::string & prefix)
}
+// FIXME: DRY and match or use the parser
static bool isVarName(std::string_view s)
{
if (s.size() == 0) return false;
@@ -956,10 +957,7 @@ std::ostream & NixRepl::printValue(std::ostream & str, Value & v, unsigned int m
sorted.emplace(state->symbols[i.name], i.value);
for (auto & i : sorted) {
- if (isVarName(i.first))
- str << i.first;
- else
- printLiteralString(str, i.first);
+ printAttributeName(str, i.first);
str << " = ";
if (seen.count(i.second))
str << "«repeated»";
diff --git a/src/libexpr/nixexpr.cc b/src/libexpr/nixexpr.cc
index d8f3cd701..1557cbbeb 100644
--- a/src/libexpr/nixexpr.cc
+++ b/src/libexpr/nixexpr.cc
@@ -61,33 +61,12 @@ Pos::operator std::shared_ptr<AbstractPos>() const
return pos;
}
-/* Displaying abstract syntax trees. */
-
+// FIXME: remove, because *symbols* are abstract and do not have a single
+// textual representation; see printIdentifier()
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
- str << '"' << s << '"';
- else {
- char c = s[0];
- if (!((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_')) {
- printLiteralString(str, s);
- return str;
- }
- for (auto c : s)
- if (!((c >= 'a' && c <= 'z') ||
- (c >= 'A' && c <= 'Z') ||
- (c >= '0' && c <= '9') ||
- c == '_' || c == '\'' || c == '-')) {
- printLiteralString(str, s);
- return str;
- }
- str << s;
- }
- return str;
+ return printIdentifier(str, s);
}
void Expr::show(const SymbolTable & symbols, std::ostream & str) const
diff --git a/src/libexpr/print.cc b/src/libexpr/print.cc
index 282903b72..d08672cfc 100644
--- a/src/libexpr/print.cc
+++ b/src/libexpr/print.cc
@@ -25,4 +25,54 @@ printLiteralBool(std::ostream & str, bool boolean)
return str;
}
+std::ostream &
+printIdentifier(std::ostream & str, std::string_view s) {
+ if (s.empty())
+ str << "\"\"";
+ else if (s == "if") // FIXME: handle other keywords
+ str << '"' << s << '"';
+ else {
+ char c = s[0];
+ if (!((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_')) {
+ printLiteralString(str, s);
+ return str;
+ }
+ for (auto c : s)
+ if (!((c >= 'a' && c <= 'z') ||
+ (c >= 'A' && c <= 'Z') ||
+ (c >= '0' && c <= '9') ||
+ c == '_' || c == '\'' || c == '-')) {
+ printLiteralString(str, s);
+ return str;
+ }
+ str << s;
+ }
+ return str;
+}
+
+// FIXME: keywords
+static bool isVarName(std::string_view s)
+{
+ if (s.size() == 0) return false;
+ char c = s[0];
+ if ((c >= '0' && c <= '9') || c == '-' || c == '\'') return false;
+ for (auto & i : s)
+ if (!((i >= 'a' && i <= 'z') ||
+ (i >= 'A' && i <= 'Z') ||
+ (i >= '0' && i <= '9') ||
+ i == '_' || i == '-' || i == '\''))
+ return false;
+ return true;
+}
+
+std::ostream &
+printAttributeName(std::ostream & str, std::string_view name) {
+ if (isVarName(name))
+ str << name;
+ else
+ printLiteralString(str, name);
+ return str;
+}
+
+
}
diff --git a/src/libexpr/print.hh b/src/libexpr/print.hh
index 98dd2008d..f9cfc3964 100644
--- a/src/libexpr/print.hh
+++ b/src/libexpr/print.hh
@@ -27,4 +27,22 @@ namespace nix {
/** Print `true` or `false`. */
std::ostream & printLiteralBool(std::ostream & o, bool b);
+
+ /**
+ * Print a string as an attribute name in the Nix expression language syntax.
+ *
+ * Prints a quoted string if necessary.
+ */
+ std::ostream & printAttributeName(std::ostream & o, std::string_view s);
+
+ /**
+ * Print a string as an identifier in the Nix expression language syntax.
+ *
+ * FIXME: "identifier" is ambiguous. Identifiers do not have a single
+ * textual representation. They can be used in variable references,
+ * let bindings, left-hand sides or attribute names in a select
+ * expression, or something else entirely, like JSON. Use one of the
+ * `print*` functions instead.
+ */
+ std::ostream & printIdentifier(std::ostream & o, std::string_view s);
}