/// <summary>
/// Consume a JSON numeric token
/// </summary>
/// <param name="ctx"></param>
/// <param name="throws"></param>
/// <returns></returns>
private static JsonParserContext ConsumeNumber(
this JsonParserContext ctx,
bool throws
)
{
const string Leading = "-0123456789";
const string Allowed = Leading + ".Ee+";
if (ctx.ConsumeWhiteSpace().ConsumeAnyChar(Leading, throws).IsSucceeded)
{
JSonReader src = ctx.Begin();
for (int p = src.Position, len = src.Text.Length; p < len; p++)
{
if (Allowed.IndexOf(src.Text[p]) < 0)
{
ctx.SetResult(
new JValue {
BoxedValue = double.Parse(src.Text.Substring(src.Position - 1, p - src.Position + 1))
}
);
src.Position = p;
break;
}
}
}
return(ctx);
}
/// <summary>
/// Consume a JSON string token
/// </summary>
/// <param name="ctx"></param>
/// <param name="throws"></param>
/// <returns></returns>
private static JsonParserContext ConsumeString(
this JsonParserContext ctx,
bool throws
)
{
if (ctx.ConsumeWhiteSpace().ConsumeAnyChar("\"", throws).IsSucceeded)
{
JSonReader src = ctx.Begin();
for (int p = src.Position, len = src.Text.Length; p < len; p++)
{
if ((src.Text[p]) == '"')
{
ctx.SetResult(
new JValue {
BoxedValue = src.Text.Substring(src.Position, p - src.Position)
}
);
src.Position = p + 1;
break;
}
}
}
return(ctx);
}
/// <summary>
/// Consume a JSON array
/// </summary>
/// <param name="ctx"></param>
/// <param name="throws"></param>
/// <returns></returns>
private static JsonParserContext ConsumeArray(
this JsonParserContext ctx,
bool throws
)
{
if (ctx.ConsumeWhiteSpace().ConsumeAnyChar("[", throws).IsSucceeded)
{
var jctr = new JArray();
bool shouldThrow = false;
do
{
ctx.Begin();
if (ctx.ConsumeValue(shouldThrow).IsSucceeded)
{
jctr.Add((JToken)ctx.Result);
}
shouldThrow = true;
}while ((char)ctx.ConsumeWhiteSpace().ConsumeAnyChar(",]", true).Result == ',');
ctx.SetResult(jctr);
}
return(ctx);
}
/// <summary>
/// Consume a JSON object
/// </summary>
/// <param name="ctx"></param>
/// <param name="throws"></param>
/// <returns></returns>
private static JsonParserContext ConsumeObject(
this JsonParserContext ctx,
bool throws
)
{
if (ctx.ConsumeWhiteSpace().ConsumeAnyChar("{", throws).IsSucceeded)
{
var jctr = new JObject();
bool shouldThrow = false;
do
{
ctx.Begin();
if (ctx.ConsumeString(shouldThrow).IsSucceeded)
{
var name = (string)(JValue)ctx.Result;
ctx.ConsumeWhiteSpace()
.ConsumeAnyChar(":", true)
.ConsumeValue(true);
jctr.Add(name, (JToken)ctx.Result);
}
shouldThrow = true;
}while ((char)ctx.ConsumeWhiteSpace().ConsumeAnyChar(",}", true).Result == ',');
ctx.SetResult(jctr);
}
return(ctx);
}
/// <summary>
/// Consume all the characters in the specified sequence
/// </summary>
/// <param name="ctx"></param>
/// <param name="sequence"></param>
/// <param name="throws"></param>
/// <returns></returns>
private static JsonParserContext ConsumeAllChars(
this JsonParserContext ctx,
string sequence,
bool throws
)
{
JSonReader src = ctx.Begin();
for (int q = 0, p = src.Position; q < sequence.Length; q++, p++)
{
if (src.Text[p] != sequence[q])
{
if (throws)
{
throw new JsonParseException("Expected char not found.");
}
return(ctx);
}
}
src.Position += sequence.Length;
ctx.SetResult(sequence);
return(ctx);
}
/// <summary>
/// Parse a JSON-string to a specific DOM
/// </summary>
/// <param name="text"></param>
/// <returns></returns>
public static JToken Parse(string text)
{
var rd = new JSonReader(text);
var ctx = new JsonParserContext(rd)
.ConsumeWhiteSpace()
.First(true, JsonHelpers.ConsumeObject, JsonHelpers.ConsumeArray);
return((JToken)ctx.Result);
}
/// <summary>
/// Consume any suitable JSON value token
/// </summary>
/// <param name="ctx"></param>
/// <param name="throws"></param>
/// <returns></returns>
private static JsonParserContext ConsumeValue(
this JsonParserContext ctx,
bool throws
)
{
return(ctx.First(
throws,
JsonHelpers.ConsumeString,
JsonHelpers.ConsumeNumber,
JsonHelpers.ConsumeObject,
JsonHelpers.ConsumeArray,
JsonHelpers.ConsumeBoolean,
JsonHelpers.ConsumeNull
));
}
/// <summary>
/// Consume an arbitrary number of whitespace characters
/// </summary>
/// <param name="ctx"></param>
/// <returns></returns>
private static JsonParserContext ConsumeWhiteSpace(
this JsonParserContext ctx
)
{
JSonReader src = ctx.Begin();
for (int p = src.Position, len = src.Text.Length; p < len; p++)
{
if (WhiteSpace.IndexOf(src.Text[p]) < 0)
{
src.Position = p;
break;
}
}
return(ctx);
}
/// <summary>
/// Consume the JSON "null" token
/// </summary>
/// <param name="ctx"></param>
/// <param name="throws"></param>
/// <returns></returns>
private static JsonParserContext ConsumeNull(
this JsonParserContext ctx,
bool throws
)
{
if (ctx.ConsumeWhiteSpace().ConsumeAnyChar("n", throws).IsSucceeded)
{
ctx.ConsumeAllChars("ull", true);
ctx.SetResult(
new JValue {
BoxedValue = null
}
);
}
return(ctx);
}
/// <summary>
/// Consume a JSON boolean token
/// </summary>
/// <param name="ctx"></param>
/// <param name="throws"></param>
/// <returns></returns>
private static JsonParserContext ConsumeBoolean(
this JsonParserContext ctx,
bool throws
)
{
if (ctx.ConsumeWhiteSpace().ConsumeAnyChar("ft", throws).IsSucceeded)
{
bool flag = (char)ctx.Result == 't';
ctx.ConsumeAllChars(flag ? "rue" : "alse", true);
ctx.SetResult(
new JValue {
BoxedValue = flag
}
);
}
return(ctx);
}
/// <summary>
/// Consume any character (at least one) in the specified set
/// </summary>
/// <param name="ctx"></param>
/// <param name="charset"></param>
/// <param name="throws"></param>
/// <returns></returns>
private static JsonParserContext ConsumeAnyChar(
this JsonParserContext ctx,
string charset,
bool throws
)
{
JSonReader src = ctx.Begin();
char c;
if (charset.IndexOf(c = src.Text[src.Position]) >= 0)
{
src.Position++;
ctx.SetResult(c);
}
else if (throws)
{
throw new JsonParseException("Expected char not found.");
}
return(ctx);
}
/// <summary>
/// Yield the consumption of the current context to a series of possible parsers
/// The control will pass to the first one able to manage the source.
/// </summary>
/// <param name="ctx"></param>
/// <param name="throws"></param>
/// <param name="funcs"></param>
/// <returns></returns>
private static JsonParserContext First(
this JsonParserContext ctx,
bool throws,
params JsonParseDelegate[] funcs
)
{
for (int i = 0; i < funcs.Length; i++)
{
if (funcs[i](ctx, false).IsSucceeded)
{
return(ctx);
}
}
if (throws)
{
throw new JsonParseException("Unmatched handler for context.");
}
else
{
return(ctx);
}
}
/// <summary>
/// Parse a JSON-string to a specific DOM
/// </summary>
/// <param name="text"></param>
/// <returns></returns>
public static JToken Parse(string text)
{
var rd = new JSonReader(text);
var ctx = new JsonParserContext(rd)
.ConsumeWhiteSpace()
.First(true, JsonHelpers.ConsumeObject, JsonHelpers.ConsumeArray);
return (JToken)ctx.Result;
}
