--- /dev/null
+/*
+Copyright (C) 2021 David Knapp (Cloudwalk)
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+*/
+
+#include "quakedef.h"
+#include <setjmp.h>
+
+// taken from json's wikipedia article
+const char json_test_string[] =
+{
+ "{\n"
+ "\t\"firstName\": \"John\",\n"
+ "\t\"lastName\": \"Smith\",\n"
+ "\t\"isAlive\": true,\n"
+ "\t\"age\": 27,\n"
+ "\t\"address\": {\n"
+ "\t\t\"streetAddress\": \"21 2nd Street\",\n"
+ "\t\t\"city\": \"New York\",\n"
+ "\t\t\"state\": \"NY\",\n"
+ "\t\t\"postalCode\": \"10021-3100\"\n"
+ "\t},\n"
+ "\t\"phoneNumbers\": [\n"
+ "\t\t{\n"
+ "\t\t\t\"type\": \"home\",\n"
+ "\t\t\t\"number\": \"212 555-1234\"\n"
+ "\t\t},\n"
+ "\t\t{\n"
+ "\t\t\t\"type\": \"office\",\n"
+ "\t\t\t\"number\": \"646 555-4567\"\n"
+ "\t\t}\n"
+ "\t],\n"
+ "\t\"children\": [],\n"
+ "\t\"spouse\": null\n"
+ "}\n\000"
+};
+
+static jmp_buf json_error;
+
+typedef enum qjson_err_e
+{
+ JSON_ERR_SUCCESS = 0,
+ JSON_ERR_INVAL = 1,
+ JSON_ERR_EOF = 2,
+ JSON_ERR_EMPTY = 3
+} qjson_err_t;
+
+typedef enum qjson_type_e
+{
+ JSON_TYPE_UNDEFINED = 0,
+ JSON_TYPE_OBJECT = 1,
+ JSON_TYPE_ARRAY = 2,
+ JSON_TYPE_STRING = 3,
+ JSON_TYPE_PRIMITIVE = 4
+} qjson_type_t;
+
+typedef struct qjson_token_s
+{
+ qjson_type_t type;
+ struct qjson_token_s *next; // if an array, next will be a NULL terminated array
+ char *string; // ASCII only for now
+} qjson_token_t;
+
+struct qjson_state_s
+{
+ qjson_token_t *head, *cur;
+ const char *buf;
+ const char *pos;
+ int line, col;
+};
+
+static void Json_Parse_Object(struct qjson_state_s *state);
+static void Json_Parse_Array(struct qjson_state_s *state);
+
+// Tell the user that their json is broken, why it's broken, and where it's broken, so hopefully they fix it.
+static void Json_Parse_Error(struct qjson_state_s *state, qjson_err_t error)
+{
+ if(!error)
+ return;
+ else
+ {
+ switch (error)
+ {
+ case JSON_ERR_INVAL:
+ Con_Printf(CON_ERROR "Json Error: Unexpected token '%c', line %i, column %i\n", *state->pos, state->line, state->col);
+ break;
+ case JSON_ERR_EOF:
+ Con_Printf(CON_ERROR "Json Error: Unexpected end-of-file\n");
+ break;
+ default:
+ return;
+ }
+ }
+ longjmp(json_error, 1);
+}
+
+// Skips newlines, and handles different line endings.
+static qbool Json_Parse_Newline(struct qjson_state_s *state)
+{
+ if(*state->pos == '\n')
+ goto newline;
+ if(*state->pos == '\r')
+ {
+ if(*state->pos + 1 == '\n')
+ state->pos++;
+ goto newline;
+ }
+ return false;
+newline:
+ state->col = 1;
+ state->line++;
+ state->pos++;
+ return true;
+}
+
+// Skips the current line. Only useful for comments.
+static void Json_Parse_SkipLine(struct qjson_state_s *state)
+{
+ while(!Json_Parse_Newline(state))
+ state->pos++;
+}
+
+// Checks for C/C++-style comments and ignores them. This is not standard json.
+static qbool Json_Parse_Comment(struct qjson_state_s *state)
+{
+ if(*state->pos == '/')
+ {
+ if(*state->pos++ == '/')
+ Json_Parse_SkipLine(state);
+ else if(*state->pos == '*')
+ {
+ while(*state->pos++ != '*' && *state->pos + 1 != '/')
+ continue;
+ }
+ else
+ Json_Parse_Error(state, JSON_ERR_INVAL);
+ return true;
+ }
+ return false;
+}
+
+// Advance forward in the stream as many times as 'count', cleanly.
+static void Json_Parse_Next(struct qjson_state_s *state, size_t count)
+{
+ state->col = state->col + count;
+ state->pos = state->pos + count;
+
+ if(!*state->pos)
+ Json_Parse_Error(state, JSON_ERR_EOF);
+}
+
+// Skip all whitespace, as we normally know it.
+static void Json_Parse_Whitespace(struct qjson_state_s *state)
+{
+ while(*state->pos == ' ' || *state->pos == '\t')
+ Json_Parse_Next(state, 1);
+}
+
+// Skip all whitespace, as json defines it.
+static void Json_Parse_Skip(struct qjson_state_s *state)
+{
+ /*
+ * Repeat this until we run out of whitespace, newlines, and comments.
+ * state->pos should be left on non-whitespace when this returns.
+ */
+ do {
+ Json_Parse_Whitespace(state);
+ } while (Json_Parse_Comment(state) || Json_Parse_Newline(state));
+}
+
+// Skip to the next token that isn't whitespace. Hopefully a valid one.
+static char Json_Parse_NextToken(struct qjson_state_s *state)
+{
+ /*
+ * This assumes state->pos is already on whitespace. Most of the time this
+ * doesn't happen automatically, but advancing the pointer here would break
+ * comment and newline handling when it does happen automatically.
+ */
+ Json_Parse_Skip(state);
+ return *state->pos;
+}
+
+// TODO: handle escape sequences
+static void Json_Parse_String(struct qjson_state_s *state)
+{
+ do {
+ Json_Parse_Next(state, 1);
+ if(*state->pos == '\\')
+ Json_Parse_Next(state, 1);
+ } while(*state->pos != '"');
+
+ Json_Parse_Next(state, 1);
+}
+
+// Handles numbers. Json numbers can be either an integer or a double.
+static qbool Json_Parse_Number(struct qjson_state_s *state)
+{
+ int i, numsize;
+ const char *in = state->pos;
+ //char out[128];
+ qbool is_float = false;
+ qbool is_exp = false;
+
+ for(i = 0, numsize = 0; isdigit(in[i]); i++, numsize++)
+ {
+ //out[numsize] = in[numsize];
+
+ if(in[i] == '.')
+ {
+ if(is_float || is_exp)
+ Json_Parse_Error(state, JSON_ERR_INVAL);
+ is_float = true;
+ i++;
+ continue;
+ }
+
+ if(in[i] == 'e' || in[i] == 'E')
+ {
+ if(is_exp)
+ Json_Parse_Error(state, JSON_ERR_INVAL);
+ if(in[i+1] == '+' || in[i+1] == '-')
+ i++;
+ is_exp = true;
+ i++;
+ continue;
+ }
+ }
+ // TODO: use strtod()
+ Json_Parse_Next(state, i);
+ return true;
+}
+
+// Parse a keyword.
+static qbool Json_Parse_Keyword(struct qjson_state_s *state, const char *keyword)
+{
+ size_t keyword_size = strlen(keyword);
+ if(!strncmp(keyword, state->pos, keyword_size))
+ {
+ Json_Parse_Next(state, keyword_size);
+ return true;
+ }
+ return false;
+}
+
+// Parse a value.
+static void Json_Parse_Value(struct qjson_state_s *state)
+{
+ Json_Parse_Next(state, 1);
+
+ switch(Json_Parse_NextToken(state))
+ {
+ case '"': // string
+ Json_Parse_String(state);
+ break;
+ case '{': // object
+ Json_Parse_Object(state);
+ break;
+ case '[': // array
+ Json_Parse_Array(state);
+ break;
+ case '-':
+ Json_Parse_Number(state);
+ break;
+ default:
+ if(Json_Parse_Keyword(state, "true"))
+ break;
+ if(Json_Parse_Keyword(state, "false"))
+ break;
+ if(Json_Parse_Keyword(state, "null"))
+ break;
+ if(isdigit(*state->pos))
+ Json_Parse_Number(state);
+ }
+}
+
+// Parse an object.
+static void Json_Parse_Object(struct qjson_state_s *state)
+{
+ /*
+ * Json objects are basically a data map; key-value pairs.
+ * They end in a comma or a closing curly brace.
+ */
+ do {
+ Json_Parse_Next(state, 1);
+
+ // Parse the key
+ if(Json_Parse_NextToken(state) == '"')
+ Json_Parse_String(state);
+ else
+ goto fail;
+
+ // And its value
+ if(Json_Parse_NextToken(state) == ':')
+ Json_Parse_Value(state);
+ else
+ goto fail;
+ } while (Json_Parse_NextToken(state) == ',');
+
+ if(Json_Parse_NextToken(state) == '}')
+ return;
+fail:
+ Json_Parse_Error(state, JSON_ERR_INVAL);
+}
+
+// Parse an array.
+static void Json_Parse_Array(struct qjson_state_s *state)
+{
+ /*
+ * Json arrays are basically lists. They can contain
+ * any value, comma-separated, and end with a closing square bracket.
+ */
+ do {
+ Json_Parse_Value(state);
+ } while (Json_Parse_NextToken(state) == ',');
+
+ if(Json_Parse_NextToken(state) == ']')
+ return;
+ else
+ Json_Parse_Error(state, JSON_ERR_INVAL);
+}
+
+// Main function for the parser.
+qjson_token_t *Json_Parse(const char *data)
+{
+ struct qjson_state_s state =
+ {
+ .head = NULL,
+ .buf = data,
+ .pos = &data[0],
+ .line = 1,
+ .col = 1
+ };
+
+ if(data == NULL)
+ {
+ Con_Printf(CON_ERROR "Json_Parse: Empty json file\n");
+ return NULL;
+ }
+
+ if(setjmp(json_error))
+ {
+ // actually not sure about this
+ return NULL;
+ }
+
+ if(Json_Parse_NextToken(&state) == '{')
+ Json_Parse_Object(&state);
+ else
+ {
+ Con_Printf(CON_ERROR "Json_Parse: Not a json file\n");
+ return NULL;
+ }
+
+ // Success!
+ // TODO: Actually parse.
+ Con_Printf("Hmm, yes. This json is made of json\n");
+
+ return state.head;
+}
+
+void Json_Test_f(cmd_state_t *cmd)
+{
+ Json_Parse(json_test_string);
+}
projects / xonotic / darkplaces.git / commitdiff