2 * Copyright (c) 2011 Sveriges Television AB <info@casparcg.com>
4 * This file is part of CasparCG (www.casparcg.com).
6 * CasparCG is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * CasparCG is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with CasparCG. If not, see <http://www.gnu.org/licenses/>.
19 * Author: Helge Norberg, helge.norberg@svt.se
22 #include "../../StdAfx.h"
24 #include "expression_parser.h"
33 #include <boost/any.hpp>
35 #include <common/log.h>
36 #include <common/except.h>
37 #include <common/utf.h>
39 namespace caspar { namespace core { namespace scene {
41 wchar_t next_non_whitespace(
42 std::wstring::const_iterator& cursor,
43 const std::wstring& str,
44 const std::wstring& error_if_eof)
46 while (cursor != str.end())
59 CASPAR_THROW_EXCEPTION(user_error() << msg_info(
60 L"Unexpected end of input (" + error_if_eof + L") in " + str));
63 std::wstring at_position(
64 const std::wstring::const_iterator& cursor, const std::wstring& str)
66 int index = static_cast<int>(cursor - str.begin());
68 return L" at index " + boost::lexical_cast<std::wstring>(index)
72 boost::any parse_expression(
73 std::wstring::const_iterator& cursor,
74 const std::wstring& str,
75 const variable_repository& var_repo);
77 boost::any parse_parenthesis(
78 std::wstring::const_iterator& cursor,
79 const std::wstring& str,
80 const variable_repository& var_repo)
82 if (*cursor++ != L'(')
83 CASPAR_THROW_EXCEPTION(user_error()
84 << msg_info(L"Expected (" + at_position(cursor, str)));
86 auto expr = parse_expression(cursor, str, var_repo);
88 if (*cursor++ != L')')
89 CASPAR_THROW_EXCEPTION(user_error()
90 << msg_info(L"Expected )" + at_position(cursor, str)));
95 double parse_constant(
96 std::wstring::const_iterator& cursor, const std::wstring& str)
98 std::wstring constant;
100 while (cursor != str.end())
102 wchar_t ch = *cursor;
104 if ((ch >= L'0' && ch <= L'9') || ch == L'.')
112 return boost::lexical_cast<double>(constant);
115 std::wstring parse_string_literal(
116 std::wstring::const_iterator& cursor, const std::wstring& str)
118 std::wstring literal;
120 if (*cursor++ != L'"')
121 CASPAR_THROW_EXCEPTION(user_error()
122 << msg_info(L"Expected (" + at_position(cursor, str)));
124 bool escaping = false;
126 while (cursor != str.end())
128 wchar_t ch = *cursor;
151 return std::move(literal);
169 CASPAR_THROW_EXCEPTION(user_error() << msg_info(
170 L"Unexpected end of input (Expected closing \") in " + str));
173 boost::any parse_variable(
174 std::wstring::const_iterator& cursor,
175 const std::wstring& str,
176 const variable_repository& var_repo)
178 std::wstring variable_name;
180 while (cursor != str.end())
182 wchar_t ch = *cursor;
186 || (ch >= L'a' && ch <= L'z')
187 || (ch >= L'A' && ch <= L'Z')
188 || (variable_name.length() > 0 && ch >= L'0' && ch <= L'9'))
196 if (variable_name == L"true")
198 else if (variable_name == L"false")
201 variable& var = var_repo(variable_name);
203 if (var.is<double>())
204 return var.as<double>();
205 else if (var.is<int64_t>())
206 return var.as<int64_t>().as<double>();
207 else if (var.is<std::wstring>())
208 return var.as<std::wstring>();
209 else if (var.is<bool>())
210 return var.as<bool>();
212 CASPAR_THROW_EXCEPTION(user_error() << msg_info(
213 L"Unhandled variable type of " + variable_name
214 + at_position(cursor, str)));
226 std::wstring characters;
230 op(wchar_t ch, int precedence, op_type type)
231 : characters(1, ch), precedence(precedence), type(type)
235 op(const std::wstring& chs, int precedence, op_type type)
236 : characters(chs), precedence(precedence), type(type)
241 op parse_operator(std::wstring::const_iterator& cursor, const std::wstring& str)
243 static const wchar_t NONE = L' ';
244 wchar_t first = NONE;
246 while (cursor != str.end())
248 wchar_t ch = *cursor;
254 return op(ch, 6, op::op_type::BINARY);
259 return op(ch, 5, op::op_type::BINARY);
263 return op(ch, 15, op::op_type::TERNARY);
266 CASPAR_THROW_EXCEPTION(user_error() << msg_info(
267 L"Did not expect -" + at_position(cursor, str)));
275 CASPAR_THROW_EXCEPTION(user_error() << msg_info(
276 L"Did not expect !" + at_position(cursor, str)));
284 CASPAR_THROW_EXCEPTION(user_error() << msg_info(
285 L"Did not expect <" + at_position(cursor, str)));
293 CASPAR_THROW_EXCEPTION(user_error() << msg_info(
294 L"Did not expect >" + at_position(cursor, str)));
304 return op(L"==", 9, op::op_type::BINARY);
306 else if (first == L'!')
309 return op(L"!=", 9, op::op_type::BINARY);
311 else if (first == L'>')
314 return op(L">=", 8, op::op_type::BINARY);
316 else if (first == L'<')
319 return op(L"<=", 8, op::op_type::BINARY);
321 else if (first == NONE)
327 CASPAR_THROW_EXCEPTION(user_error() << msg_info(
328 L"Did not expect =" + at_position(cursor, str)));
335 return op(L"||", 14, op::op_type::BINARY);
337 else if (first == NONE)
343 CASPAR_THROW_EXCEPTION(user_error() << msg_info(
344 L"Did not expect =" + at_position(cursor, str)));
351 return op(L"&&", 13, op::op_type::BINARY);
353 else if (first == NONE)
359 CASPAR_THROW_EXCEPTION(user_error() << msg_info(
360 L"Did not expect =" + at_position(cursor, str)));
366 return op(L'-', 6, op::op_type::BINARY);
367 else if (first == L'!')
368 return op(L'!', 3, op::op_type::UNARY);
371 return op(L'<', 8, op::op_type::BINARY);
372 else if (first == L'>')
373 return op(L'>', 8, op::op_type::BINARY);
374 else if (first == L'-')
375 return op(L"unary-", 3, op::op_type::UNARY);
376 else if (first == L'!')
377 return op(L'!', 3, op::op_type::UNARY);
379 CASPAR_THROW_EXCEPTION(user_error() << msg_info(
380 L"Expected second character of operator"
381 + at_position(cursor, str)));
385 CASPAR_THROW_EXCEPTION(user_error() << msg_info(
386 L"Unexpected end of input (Expected operator) in " + str));
389 boost::any as_binding(const boost::any& value)
391 // Wrap supported constants as bindings
392 if (is<double>(value))
393 return binding<double>(as<double>(value));
394 else if (is<bool>(value))
395 return binding<bool>(as<bool>(value));
396 else if (is<std::wstring>(value))
397 return binding<std::wstring>(as<std::wstring>(value));
398 // Already one of the supported binding types
399 else if (is<binding<double>>(value))
400 return as<binding<double>>(value);
401 else if (is<binding<bool>>(value))
402 return as<binding<bool>>(value);
403 else if (is<binding<std::wstring>>(value))
404 return as<binding<std::wstring>>(value);
406 CASPAR_THROW_EXCEPTION(user_error() << msg_info(
407 L"Couldn't detect type of " + u16(value.type().name())));
411 binding<T> require(const boost::any& value)
413 auto b = as_binding(value);
415 if (is<binding<T>>(b))
416 return as<binding<T>>(b);
418 CASPAR_THROW_EXCEPTION(user_error() << msg_info(
419 L"Required binding of type " + u16(typeid(T).name())
420 + L" but got " + u16(value.type().name())));
423 boost::any negative(const boost::any& to_create_negative_of)
425 return -require<double>(to_create_negative_of);
428 boost::any not_(const boost::any& to_create_not_of)
430 return !require<bool>(to_create_not_of);
433 boost::any multiply(const boost::any& lhs, boost::any& rhs)
435 return require<double>(lhs) * require<double>(rhs);
438 boost::any divide(const boost::any& lhs, boost::any& rhs)
440 return require<double>(lhs) / require<double>(rhs);
443 boost::any modulus(const boost::any& lhs, boost::any& rhs)
447 require<double>(lhs).as<int64_t>()
448 % require<double>(rhs).as<int64_t>()
452 binding<std::wstring> stringify(const boost::any& value)
454 auto b = as_binding(value);
456 if (is<binding<std::wstring>>(b))
457 return as<binding<std::wstring>>(b);
458 else if (is<binding<double>>(b))
459 return as<binding<double>>(b).as<std::wstring>();
460 else if (is<binding<bool>>(b))
461 return as<binding<bool>>(b).as<std::wstring>();
463 CASPAR_THROW_EXCEPTION(user_error()
464 << msg_info(L"Couldn't stringify " + u16(value.type().name())));
467 boost::any add(const boost::any& lhs, boost::any& rhs)
469 auto l = as_binding(lhs);
470 auto r = as_binding(rhs);
473 if (is<binding<double>>(l) && is<binding<double>>(r))
474 return as<binding<double>>(l) + as<binding<double>>(r);
476 else if (is<binding<std::wstring>>(l) && is<binding<std::wstring>>(r))
477 return as<binding<std::wstring>>(l) + as<binding<std::wstring>>(r);
478 // mixed types to string and concatenated
480 return stringify(lhs) + stringify(rhs);
483 boost::any subtract(const boost::any& lhs, boost::any& rhs)
485 return require<double>(lhs) - require<double>(rhs);
488 boost::any less(const boost::any& lhs, boost::any& rhs)
490 return require<double>(lhs) < require<double>(rhs);
493 boost::any less_or_equal(const boost::any& lhs, boost::any& rhs)
495 return require<double>(lhs) <= require<double>(rhs);
498 boost::any greater(const boost::any& lhs, boost::any& rhs)
500 return require<double>(lhs) > require<double>(rhs);
503 boost::any greater_or_equal(const boost::any& lhs, boost::any& rhs)
505 return require<double>(lhs) >= require<double>(rhs);
508 boost::any equal(const boost::any& lhs, boost::any& rhs)
510 auto l = as_binding(lhs);
511 auto r = as_binding(rhs);
514 if (is<binding<double>>(l) && is<binding<double>>(r))
515 return as<binding<double>>(l) == as<binding<double>>(r);
517 else if (is<binding<std::wstring>>(l) && is<binding<std::wstring>>(r))
518 return as<binding<std::wstring>>(l) == as<binding<std::wstring>>(r);
521 return require<bool>(l) == require<bool>(r);
524 boost::any and_(const boost::any& lhs, boost::any& rhs)
526 return require<bool>(lhs) && require<bool>(rhs);
529 boost::any or_(const boost::any& lhs, boost::any& rhs)
531 return require<bool>(lhs) || require<bool>(rhs);
536 const binding<bool>& condition,
537 const binding<T>& true_value,
538 const binding<T>& false_value)
540 return when(condition).then(true_value).otherwise(false_value);
544 const boost::any& condition,
545 const boost::any& true_value,
546 const boost::any& false_value)
548 auto cond = require<bool>(condition);
549 auto t = as_binding(true_value);
550 auto f = as_binding(false_value);
553 if (is<binding<double>>(t) && is<binding<double>>(f))
554 return ternary(cond, as<binding<double>>(t), as<binding<double>>(f));
556 else if (is<binding<std::wstring>>(t) && is<binding<std::wstring>>(f))
559 as<binding<std::wstring>>(t),
560 as<binding<std::wstring>>(f));
563 return ternary(cond, require<bool>(t), require<bool>(f));
566 void resolve_operators(int precedence, std::vector<boost::any>& tokens)
568 for (int i = 0; i < tokens.size(); ++i)
570 auto& token = tokens.at(i);
575 auto op_token = as<op>(token);
577 if (op_token.precedence != precedence)
580 int index_after = i + 1;
581 auto& token_after = tokens.at(index_after);
583 switch (op_token.type)
585 case op::op_type::UNARY:
586 if (op_token.characters == L"unary-")
588 tokens.at(i) = negative(token_after);
590 else if (op_token.characters == L"!")
592 tokens.at(i) = not_(token_after);
595 tokens.erase(tokens.begin() + index_after);
598 case op::op_type::BINARY:
600 auto& token_before = tokens.at(i - 1);
602 if (op_token.characters == L"*")
603 token_before = multiply(token_before, token_after);
604 else if (op_token.characters == L"/")
605 token_before = divide(token_before, token_after);
606 else if (op_token.characters == L"%")
607 token_before = modulus(token_before, token_after);
608 else if (op_token.characters == L"+")
609 token_before = add(token_before, token_after);
610 else if (op_token.characters == L"-")
611 token_before = subtract(token_before, token_after);
612 else if (op_token.characters == L"<")
613 token_before = less(token_before, token_after);
614 else if (op_token.characters == L"<=")
615 token_before = less_or_equal(token_before, token_after);
616 else if (op_token.characters == L">")
617 token_before = greater(token_before, token_after);
618 else if (op_token.characters == L">=")
619 token_before = greater_or_equal(token_before, token_after);
620 else if (op_token.characters == L"==")
621 token_before = equal(token_before, token_after);
622 else if (op_token.characters == L"!=")
623 token_before = not_(equal(token_before, token_after));
624 else if (op_token.characters == L"&&")
625 token_before = and_(token_before, token_after);
626 else if (op_token.characters == L"||")
627 token_before = or_(token_before, token_after);
630 tokens.erase(tokens.begin() + i, tokens.begin() + i + 2);
634 case op::op_type::TERNARY:
635 if (op_token.characters == L"?")
637 auto& token_before = tokens.at(i - 1);
638 auto& token_colon_operator = tokens.at(i + 2);
640 if (as<op>(token_colon_operator).characters != L":")
641 CASPAR_THROW_EXCEPTION(user_error() << msg_info(
642 L"Expected : as part of ternary expression"));
644 auto& token_false_value = tokens.at(i + 3);
645 token_before = ternary(
646 token_before, token_after, token_false_value);
647 tokens.erase(tokens.begin() + i, tokens.begin() + i + 4);
656 boost::any parse_expression(
657 std::wstring::const_iterator& cursor,
658 const std::wstring& str,
659 const variable_repository& var_repo)
661 std::vector<boost::any> tokens;
664 while (cursor != str.end())
666 wchar_t ch = next_non_whitespace(cursor, str, L"Expected expression");
680 tokens.push_back(parse_constant(cursor, str));
695 tokens.push_back(parse_operator(cursor, str));
698 tokens.push_back(parse_string_literal(cursor, str));
701 tokens.push_back(parse_parenthesis(cursor, str, var_repo));
707 tokens.push_back(parse_variable(cursor, str, var_repo));
716 CASPAR_THROW_EXCEPTION(user_error()
717 << msg_info(L"Expected expression"));
721 while (tokens.size() > 1)
723 resolve_operators(precedence++, tokens);
726 return as_binding(tokens.at(0));