Finish initial draft of JSON parser.

This commit is contained in:
Jordan Bancino 2022-08-09 13:19:14 -04:00
parent 9d358d572f
commit 9d496c29ac

View file

@ -68,6 +68,7 @@ typedef struct JsonParserState
JsonToken tokenType;
char *token;
size_t tokenLen;
} JsonParserState;
JsonType
@ -710,8 +711,8 @@ JsonTokenSeek(JsonParserState * state)
{
int isFloat = 0;
size_t allocated = 16;
size_t len = 1;
state->tokenLen = 1;
state->token = malloc(allocated);
if (!state->token)
{
@ -724,7 +725,7 @@ JsonTokenSeek(JsonParserState * state)
{
if (c == '.')
{
if (len > 1)
if (state->tokenLen > 1)
{
isFloat = 1;
}
@ -741,7 +742,7 @@ JsonTokenSeek(JsonParserState * state)
break;
}
if (len >= allocated)
if (state->tokenLen >= allocated)
{
char *tmp;
@ -757,17 +758,17 @@ JsonTokenSeek(JsonParserState * state)
state->token = tmp;
}
state->token[len] = c;
len++;
state->token[state->tokenLen] = c;
state->tokenLen++;
}
if (state->token[len - 1] == '.')
if (state->token[state->tokenLen - 1] == '.')
{
state->tokenType = TOKEN_UNKNOWN;
return;
}
state->token[len] = '\0';
state->token[state->tokenLen] = '\0';
if (isFloat)
{
state->tokenType = TOKEN_FLOAT;
@ -779,7 +780,8 @@ JsonTokenSeek(JsonParserState * state)
}
else
{
state->token = malloc(8);
state->tokenLen = 8;
state->token = malloc(state->tokenLen);
if (!state->token)
{
state->tokenType = TOKEN_EOF;
@ -793,6 +795,7 @@ JsonTokenSeek(JsonParserState * state)
if (!strcmp("true", state->token))
{
state->tokenType = TOKEN_BOOLEAN;
state->tokenLen = 5;
}
else
{
@ -804,6 +807,7 @@ JsonTokenSeek(JsonParserState * state)
if (!strcmp("false", state->token))
{
state->tokenType = TOKEN_BOOLEAN;
state->tokenLen = 6;
}
else
{
@ -812,7 +816,7 @@ JsonTokenSeek(JsonParserState * state)
break;
case 'n':
fgets(state->token, 5, state->stream);
if (strcmp("null", state->token))
if (!strcmp("null", state->token))
{
state->tokenType = TOKEN_NULL;
}
@ -835,15 +839,172 @@ JsonExpect(JsonParserState * state, JsonToken token)
return state->tokenType == token;
}
static Array *
JsonDecodeArray(JsonParserState *);
static HashMap *
JsonDecodeObject(JsonParserState *);
static JsonValue *
JsonDecodeValue(JsonParserState * state)
{
JsonValue *value;
char *strValue;
switch (state->tokenType)
{
case TOKEN_OBJECT_OPEN:
value = JsonValueObject(JsonDecodeObject(state));
break;
case TOKEN_ARRAY_OPEN:
value = JsonValueArray(JsonDecodeArray(state));
break;
case TOKEN_STRING:
strValue = malloc(state->tokenLen);
if (!strValue)
{
return NULL;
}
strcpy(strValue, state->token);
value = JsonValueString(strValue);
break;
case TOKEN_INTEGER:
value = JsonValueInteger(atol(state->token));
break;
case TOKEN_FLOAT:
value = JsonValueFloat(atof(state->token));
break;
case TOKEN_BOOLEAN:
value = JsonValueBoolean(state->token[0] == 't');
break;
case TOKEN_NULL:
value = JsonValueNull();
break;
default:
value = NULL;
break;
}
return value;
}
static HashMap *
JsonDecodeObject(JsonParserState * state)
{
HashMap *obj = HashMapCreate();
if (!obj)
{
return NULL;
}
do
{
JsonTokenSeek(state);
if (JsonExpect(state, TOKEN_STRING))
{
char *key = malloc(state->tokenLen);
JsonValue *value;
if (!key)
{
goto error;
}
strcpy(key, state->token);
JsonTokenSeek(state);
if (!JsonExpect(state, TOKEN_COLON))
{
goto error;
}
JsonTokenSeek(state);
value = JsonDecodeValue(state);
if (!value)
{
goto error;
}
HashMapSet(obj, key, value);
JsonTokenSeek(state);
if (JsonExpect(state, TOKEN_OBJECT_CLOSE))
{
break;
}
if (JsonExpect(state, TOKEN_COMMA))
{
continue;
}
goto error;
}
else if (JsonExpect(state, TOKEN_OBJECT_CLOSE))
{
break;
}
else
{
goto error;
}
} while (!JsonExpect(state, TOKEN_EOF));
return obj;
error:
JsonFree(obj);
return NULL;
}
static Array *
JsonDecodeArray(JsonParserState * state)
{
Array *arr = ArrayCreate();
size_t i;
if (!arr)
{
return NULL;
}
do
{
JsonValue *value;
JsonTokenSeek(state);
value = JsonDecodeValue(state);
if (!value)
{
goto error;
}
ArrayAdd(arr, value);
JsonTokenSeek(state);
if (JsonExpect(state, TOKEN_ARRAY_CLOSE))
{
break;
}
if (JsonExpect(state, TOKEN_COMMA))
{
continue;
}
goto error;
} while (!JsonExpect(state, TOKEN_EOF));
return NULL;
error:
for (i = 0; i < ArraySize(arr); i++)
{
JsonValueFree((JsonValue *) ArrayGet(arr, i));
}
ArrayFree(arr);
return NULL;
}
@ -855,5 +1016,11 @@ JsonDecode(FILE * stream)
state.stream = stream;
state.token = NULL;
JsonTokenSeek(&state);
if (!JsonExpect(&state, TOKEN_OBJECT_OPEN))
{
return NULL;
}
return JsonDecodeObject(&state);
}