forked from lix-project/lix
b83801f8b3
The value pointers of lists with 1 or 2 elements are now stored in the list value itself. In particular, this makes the "concatMap (x: if cond then [(f x)] else [])" idiom cheaper.
150 lines
4.1 KiB
C++
150 lines
4.1 KiB
C++
#include "config.h"
|
||
#include "json-to-value.hh"
|
||
|
||
#include <cstring>
|
||
|
||
namespace nix {
|
||
|
||
|
||
static void skipWhitespace(const char * & s)
|
||
{
|
||
while (*s == ' ' || *s == '\t' || *s == '\n' || *s == '\r') s++;
|
||
}
|
||
|
||
|
||
#if HAVE_BOEHMGC
|
||
typedef std::vector<Value *, gc_allocator<Value *> > ValueVector;
|
||
typedef std::map<Symbol, Value *, std::less<Symbol>, gc_allocator<Value *> > ValueMap;
|
||
#else
|
||
typedef std::vector<Value *> ValueVector;
|
||
typedef std::map<Symbol, Value *> ValueMap;
|
||
#endif
|
||
|
||
|
||
static string parseJSONString(const char * & s)
|
||
{
|
||
string res;
|
||
if (*s++ != '"') throw JSONParseError("expected JSON string");
|
||
while (*s != '"') {
|
||
if (!*s) throw JSONParseError("got end-of-string in JSON string");
|
||
if (*s == '\\') {
|
||
s++;
|
||
if (*s == '"') res += '"';
|
||
else if (*s == '\\') res += '\\';
|
||
else if (*s == '/') res += '/';
|
||
else if (*s == '/') res += '/';
|
||
else if (*s == 'b') res += '\b';
|
||
else if (*s == 'f') res += '\f';
|
||
else if (*s == 'n') res += '\n';
|
||
else if (*s == 'r') res += '\r';
|
||
else if (*s == 't') res += '\t';
|
||
else if (*s == 'u') throw JSONParseError("\\u characters in JSON strings are currently not supported");
|
||
else throw JSONParseError("invalid escaped character in JSON string");
|
||
s++;
|
||
} else
|
||
res += *s++;
|
||
}
|
||
s++;
|
||
return res;
|
||
}
|
||
|
||
|
||
static void parseJSON(EvalState & state, const char * & s, Value & v)
|
||
{
|
||
skipWhitespace(s);
|
||
|
||
if (!*s) throw JSONParseError("expected JSON value");
|
||
|
||
if (*s == '[') {
|
||
s++;
|
||
ValueVector values;
|
||
values.reserve(128);
|
||
skipWhitespace(s);
|
||
while (1) {
|
||
if (values.empty() && *s == ']') break;
|
||
Value * v2 = state.allocValue();
|
||
parseJSON(state, s, *v2);
|
||
values.push_back(v2);
|
||
skipWhitespace(s);
|
||
if (*s == ']') break;
|
||
if (*s != ',') throw JSONParseError("expected ‘,’ or ‘]’ after JSON array element");
|
||
s++;
|
||
}
|
||
s++;
|
||
state.mkList(v, values.size());
|
||
for (size_t n = 0; n < values.size(); ++n)
|
||
v.listElems()[n] = values[n];
|
||
}
|
||
|
||
else if (*s == '{') {
|
||
s++;
|
||
ValueMap attrs;
|
||
while (1) {
|
||
skipWhitespace(s);
|
||
if (attrs.empty() && *s == '}') break;
|
||
string name = parseJSONString(s);
|
||
skipWhitespace(s);
|
||
if (*s != ':') throw JSONParseError("expected ‘:’ in JSON object");
|
||
s++;
|
||
Value * v2 = state.allocValue();
|
||
parseJSON(state, s, *v2);
|
||
attrs[state.symbols.create(name)] = v2;
|
||
skipWhitespace(s);
|
||
if (*s == '}') break;
|
||
if (*s != ',') throw JSONParseError("expected ‘,’ or ‘}’ after JSON member");
|
||
s++;
|
||
}
|
||
state.mkAttrs(v, attrs.size());
|
||
for (auto & i : attrs)
|
||
v.attrs->push_back(Attr(i.first, i.second));
|
||
v.attrs->sort();
|
||
s++;
|
||
}
|
||
|
||
else if (*s == '"') {
|
||
mkString(v, parseJSONString(s));
|
||
}
|
||
|
||
else if (isdigit(*s) || *s == '-') {
|
||
bool neg = false;
|
||
if (*s == '-') {
|
||
neg = true;
|
||
if (!*++s) throw JSONParseError("unexpected end of JSON number");
|
||
}
|
||
NixInt n = 0;
|
||
// FIXME: detect overflow
|
||
while (isdigit(*s)) n = n * 10 + (*s++ - '0');
|
||
if (*s == '.' || *s == 'e') throw JSONParseError("floating point JSON numbers are not supported");
|
||
mkInt(v, neg ? -n : n);
|
||
}
|
||
|
||
else if (strncmp(s, "true", 4) == 0) {
|
||
s += 4;
|
||
mkBool(v, true);
|
||
}
|
||
|
||
else if (strncmp(s, "false", 5) == 0) {
|
||
s += 5;
|
||
mkBool(v, false);
|
||
}
|
||
|
||
else if (strncmp(s, "null", 4) == 0) {
|
||
s += 4;
|
||
mkNull(v);
|
||
}
|
||
|
||
else throw JSONParseError("unrecognised JSON value");
|
||
}
|
||
|
||
|
||
void parseJSON(EvalState & state, const string & s_, Value & v)
|
||
{
|
||
const char * s = s_.c_str();
|
||
parseJSON(state, s, v);
|
||
skipWhitespace(s);
|
||
if (*s) throw JSONParseError(format("expected end-of-string while parsing JSON value: %1%") % s);
|
||
}
|
||
|
||
|
||
}
|