godot/core/variant_construct_string.cpp

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/*************************************************************************/
/* variant_construct_string.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2018 Godot Engine contributors (cf. AUTHORS.md) */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#include "variant.h"
class VariantConstruct {
enum TokenType {
TK_CURLY_BRACKET_OPEN,
TK_CURLY_BRACKET_CLOSE,
TK_BRACKET_OPEN,
TK_BRACKET_CLOSE,
TK_IDENTIFIER,
TK_STRING,
TK_NUMBER,
TK_COLON,
TK_COMMA,
TK_EOF,
TK_MAX
};
enum Expecting {
EXPECT_OBJECT,
EXPECT_OBJECT_KEY,
EXPECT_COLON,
EXPECT_OBJECT_VALUE,
};
struct Token {
TokenType type;
Variant value;
};
static const char *tk_name[TK_MAX];
static String _print_var(const Variant &p_var);
static Error _get_token(const CharType *p_str, int &index, int p_len, Token &r_token, int &line, String &r_err_str);
static Error _parse_value(Variant &value, Token &token, const CharType *p_str, int &index, int p_len, int &line, String &r_err_str, Variant::ObjectConstruct *p_construct, void *p_ud);
static Error _parse_array(Array &array, const CharType *p_str, int &index, int p_len, int &line, String &r_err_str, Variant::ObjectConstruct *p_construct, void *p_ud);
static Error _parse_dict(Dictionary &dict, const CharType *p_str, int &index, int p_len, int &line, String &r_err_str, Variant::ObjectConstruct *p_construct, void *p_ud);
public:
static Error parse(const String &p_string, Variant &r_ret, String &r_err_str, int &r_err_line, Variant::ObjectConstruct *p_construct, void *p_ud);
};
const char *VariantConstruct::tk_name[TK_MAX] = {
"'{'",
"'}'",
"'['",
"']'",
"identifier",
"string",
"number",
"':'",
"','",
"EOF",
};
Error VariantConstruct::_get_token(const CharType *p_str, int &index, int p_len, Token &r_token, int &line, String &r_err_str) {
while (true) {
switch (p_str[index]) {
case '\n': {
line++;
index++;
break;
};
case 0: {
r_token.type = TK_EOF;
return OK;
} break;
case '{': {
r_token.type = TK_CURLY_BRACKET_OPEN;
index++;
return OK;
};
case '}': {
r_token.type = TK_CURLY_BRACKET_CLOSE;
index++;
return OK;
};
case '[': {
r_token.type = TK_BRACKET_OPEN;
index++;
return OK;
};
case ']': {
r_token.type = TK_BRACKET_CLOSE;
index++;
return OK;
};
case ':': {
r_token.type = TK_COLON;
index++;
return OK;
};
case ',': {
r_token.type = TK_COMMA;
index++;
return OK;
};
case '"': {
index++;
String str;
while (true) {
if (p_str[index] == 0) {
r_err_str = "Unterminated String";
return ERR_PARSE_ERROR;
} else if (p_str[index] == '"') {
index++;
break;
} else if (p_str[index] == '\\') {
//escaped characters...
index++;
CharType next = p_str[index];
if (next == 0) {
r_err_str = "Unterminated String";
return ERR_PARSE_ERROR;
}
CharType res = 0;
switch (next) {
case 'b': res = 8; break;
case 't': res = 9; break;
case 'n': res = 10; break;
case 'f': res = 12; break;
case 'r': res = 13; break;
case '\"': res = '\"'; break;
case '\\': res = '\\'; break;
case '/': res = '/'; break;
case 'u': {
//hexnumbarh - oct is deprecated
for (int j = 0; j < 4; j++) {
CharType c = p_str[index + j + 1];
if (c == 0) {
r_err_str = "Unterminated String";
return ERR_PARSE_ERROR;
}
if (!((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'))) {
r_err_str = "Malformed hex constant in string";
return ERR_PARSE_ERROR;
}
CharType v;
if (c >= '0' && c <= '9') {
v = c - '0';
} else if (c >= 'a' && c <= 'f') {
v = c - 'a';
v += 10;
} else if (c >= 'A' && c <= 'F') {
v = c - 'A';
v += 10;
} else {
ERR_PRINT("BUG");
v = 0;
}
res <<= 4;
res |= v;
}
index += 4; //will add at the end anyway
} break;
default: {
r_err_str = "Invalid escape sequence";
return ERR_PARSE_ERROR;
} break;
}
str += res;
} else {
if (p_str[index] == '\n')
line++;
str += p_str[index];
}
index++;
}
r_token.type = TK_STRING;
r_token.value = str;
return OK;
} break;
default: {
if (p_str[index] <= 32) {
index++;
break;
}
if (p_str[index] == '-' || (p_str[index] >= '0' && p_str[index] <= '9')) {
//a number
const CharType *rptr;
double number = String::to_double(&p_str[index], &rptr);
index += (rptr - &p_str[index]);
r_token.type = TK_NUMBER;
r_token.value = number;
return OK;
} else if ((p_str[index] >= 'A' && p_str[index] <= 'Z') || (p_str[index] >= 'a' && p_str[index] <= 'z')) {
String id;
while ((p_str[index] >= 'A' && p_str[index] <= 'Z') || (p_str[index] >= 'a' && p_str[index] <= 'z')) {
id += p_str[index];
index++;
}
r_token.type = TK_IDENTIFIER;
r_token.value = id;
return OK;
} else {
r_err_str = "Unexpected character.";
return ERR_PARSE_ERROR;
}
}
}
}
return ERR_PARSE_ERROR;
}
Error VariantConstruct::_parse_value(Variant &value, Token &token, const CharType *p_str, int &index, int p_len, int &line, String &r_err_str, Variant::ObjectConstruct *p_construct, void *p_ud) {
if (token.type == TK_CURLY_BRACKET_OPEN) {
Dictionary d;
Error err = _parse_dict(d, p_str, index, p_len, line, r_err_str, p_construct, p_ud);
if (err)
return err;
value = d;
return OK;
} else if (token.type == TK_BRACKET_OPEN) {
Array a;
Error err = _parse_array(a, p_str, index, p_len, line, r_err_str, p_construct, p_ud);
if (err)
return err;
value = a;
return OK;
} else if (token.type == TK_IDENTIFIER) {
String id = token.value;
if (id == "true")
value = true;
else if (id == "false")
value = false;
else if (id == "null")
value = Variant();
else {
r_err_str = "Expected 'true','false' or 'null', got '" + id + "'.";
return ERR_PARSE_ERROR;
}
return OK;
} else if (token.type == TK_NUMBER) {
value = token.value;
return OK;
} else if (token.type == TK_STRING) {
value = token.value;
return OK;
} else {
r_err_str = "Expected value, got " + String(tk_name[token.type]) + ".";
return ERR_PARSE_ERROR;
}
return ERR_PARSE_ERROR;
}
Error VariantConstruct::_parse_array(Array &array, const CharType *p_str, int &index, int p_len, int &line, String &r_err_str, Variant::ObjectConstruct *p_construct, void *p_ud) {
Token token;
bool need_comma = false;
while (index < p_len) {
Error err = _get_token(p_str, index, p_len, token, line, r_err_str);
if (err != OK)
return err;
if (token.type == TK_BRACKET_CLOSE) {
return OK;
}
if (need_comma) {
if (token.type != TK_COMMA) {
r_err_str = "Expected ','";
return ERR_PARSE_ERROR;
} else {
need_comma = false;
continue;
}
}
Variant v;
err = _parse_value(v, token, p_str, index, p_len, line, r_err_str, p_construct, p_ud);
if (err)
return err;
array.push_back(v);
need_comma = true;
}
return OK;
}
Error VariantConstruct::_parse_dict(Dictionary &dict, const CharType *p_str, int &index, int p_len, int &line, String &r_err_str, Variant::ObjectConstruct *p_construct, void *p_ud) {
bool at_key = true;
Variant key;
Token token;
bool need_comma = false;
while (index < p_len) {
if (at_key) {
Error err = _get_token(p_str, index, p_len, token, line, r_err_str);
if (err != OK)
return err;
if (token.type == TK_CURLY_BRACKET_CLOSE) {
return OK;
}
if (need_comma) {
if (token.type != TK_COMMA) {
r_err_str = "Expected '}' or ','";
return ERR_PARSE_ERROR;
} else {
need_comma = false;
continue;
}
}
err = _parse_value(key, token, p_str, index, p_len, line, r_err_str, p_construct, p_ud);
if (err != OK)
return err;
err = _get_token(p_str, index, p_len, token, line, r_err_str);
if (err != OK)
return err;
if (token.type != TK_COLON) {
r_err_str = "Expected ':'";
return ERR_PARSE_ERROR;
}
at_key = false;
} else {
Error err = _get_token(p_str, index, p_len, token, line, r_err_str);
if (err != OK)
return err;
Variant v;
err = _parse_value(v, token, p_str, index, p_len, line, r_err_str, p_construct, p_ud);
if (err)
return err;
dict[key] = v;
need_comma = true;
at_key = true;
}
}
return OK;
}
Error VariantConstruct::parse(const String &p_string, Variant &r_ret, String &r_err_str, int &r_err_line, Variant::ObjectConstruct *p_construct, void *p_ud) {
const CharType *str = p_string.ptr();
int idx = 0;
int len = p_string.length();
Token token;
r_err_line = 0;
String aux_key;
Error err = _get_token(str, idx, len, token, r_err_line, r_err_str);
if (err)
return err;
return _parse_value(r_ret, token, str, idx, len, r_err_line, r_err_str, p_construct, p_ud);
}