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(caspar_exception() << 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(caspar_exception()
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(caspar_exception()
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(caspar_exception()
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(caspar_exception() << 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'))
195 if (variable_name == L"true")
197 else if (variable_name == L"false")
200 variable& var = var_repo(variable_name);
202 if (var.is<double>())
203 return var.as<double>();
204 else if (var.is<int64_t>())
205 return var.as<int64_t>().as<double>();
206 else if (var.is<std::wstring>())
207 return var.as<std::wstring>();
208 else if (var.is<bool>())
209 return var.as<bool>();
211 CASPAR_THROW_EXCEPTION(caspar_exception() << msg_info(
212 L"Unhandled variable type of " + variable_name
213 + at_position(cursor, str)));
225 std::wstring characters;
229 op(wchar_t ch, int precedence, op_type type)
230 : characters(1, ch), precedence(precedence), type(type)
234 op(const std::wstring& chs, int precedence, op_type type)
235 : characters(chs), precedence(precedence), type(type)
240 op parse_operator(std::wstring::const_iterator& cursor, const std::wstring& str)
242 static const wchar_t NONE = L' ';
243 wchar_t first = NONE;
245 while (cursor != str.end())
247 wchar_t ch = *cursor;
253 return op(ch, 6, op::op_type::BINARY);
258 return op(ch, 5, op::op_type::BINARY);
262 return op(ch, 15, op::op_type::TERNARY);
265 CASPAR_THROW_EXCEPTION(caspar_exception() << msg_info(
266 L"Did not expect -" + at_position(cursor, str)));
274 CASPAR_THROW_EXCEPTION(caspar_exception() << msg_info(
275 L"Did not expect !" + at_position(cursor, str)));
283 CASPAR_THROW_EXCEPTION(caspar_exception() << msg_info(
284 L"Did not expect <" + at_position(cursor, str)));
292 CASPAR_THROW_EXCEPTION(caspar_exception() << msg_info(
293 L"Did not expect >" + at_position(cursor, str)));
303 return op(L"==", 9, op::op_type::BINARY);
305 else if (first == L'!')
308 return op(L"!=", 9, op::op_type::BINARY);
310 else if (first == L'>')
313 return op(L">=", 8, op::op_type::BINARY);
315 else if (first == L'<')
318 return op(L"<=", 8, op::op_type::BINARY);
320 else if (first == NONE)
326 CASPAR_THROW_EXCEPTION(caspar_exception() << msg_info(
327 L"Did not expect =" + at_position(cursor, str)));
334 return op(L"||", 14, op::op_type::BINARY);
336 else if (first == NONE)
342 CASPAR_THROW_EXCEPTION(caspar_exception() << msg_info(
343 L"Did not expect =" + at_position(cursor, str)));
350 return op(L"&&", 13, op::op_type::BINARY);
352 else if (first == NONE)
358 CASPAR_THROW_EXCEPTION(caspar_exception() << msg_info(
359 L"Did not expect =" + at_position(cursor, str)));
365 return op(L'-', 6, op::op_type::BINARY);
366 else if (first == L'!')
367 return op(L'!', 3, op::op_type::UNARY);
370 return op(L'<', 8, op::op_type::BINARY);
371 else if (first == L'>')
372 return op(L'>', 8, op::op_type::BINARY);
373 else if (first == L'-')
374 return op(L"unary-", 3, op::op_type::UNARY);
375 else if (first == L'!')
376 return op(L'!', 3, op::op_type::UNARY);
378 CASPAR_THROW_EXCEPTION(caspar_exception() << msg_info(
379 L"Expected second character of operator"
380 + at_position(cursor, str)));
384 CASPAR_THROW_EXCEPTION(caspar_exception() << msg_info(
385 L"Unexpected end of input (Expected operator) in " + str));
388 boost::any as_binding(const boost::any& value)
390 // Wrap supported constants as bindings
391 if (is<double>(value))
392 return binding<double>(as<double>(value));
393 else if (is<bool>(value))
394 return binding<bool>(as<bool>(value));
395 else if (is<std::wstring>(value))
396 return binding<std::wstring>(as<std::wstring>(value));
397 // Already one of the supported binding types
398 else if (is<binding<double>>(value))
399 return as<binding<double>>(value);
400 else if (is<binding<bool>>(value))
401 return as<binding<bool>>(value);
402 else if (is<binding<std::wstring>>(value))
403 return as<binding<std::wstring>>(value);
405 CASPAR_THROW_EXCEPTION(caspar_exception() << msg_info(
406 L"Couldn't detect type of " + u16(value.type().name())));
410 binding<T> require(const boost::any& value)
412 auto b = as_binding(value);
414 if (is<binding<T>>(b))
415 return as<binding<T>>(b);
417 CASPAR_THROW_EXCEPTION(caspar_exception() << msg_info(
418 L"Required binding of type " + u16(typeid(T).name())
419 + L" but got " + u16(value.type().name())));
422 boost::any negative(const boost::any& to_create_negative_of)
424 return -require<double>(to_create_negative_of);
427 boost::any not_(const boost::any& to_create_not_of)
429 return !require<bool>(to_create_not_of);
432 boost::any multiply(const boost::any& lhs, boost::any& rhs)
434 return require<double>(lhs) * require<double>(rhs);
437 boost::any divide(const boost::any& lhs, boost::any& rhs)
439 return require<double>(lhs) / require<double>(rhs);
442 boost::any modulus(const boost::any& lhs, boost::any& rhs)
446 require<double>(lhs).as<int64_t>()
447 % require<double>(rhs).as<int64_t>()
451 binding<std::wstring> stringify(const boost::any& value)
453 auto b = as_binding(value);
455 if (is<binding<std::wstring>>(b))
456 return as<binding<std::wstring>>(b);
457 else if (is<binding<double>>(b))
458 return as<binding<double>>(b).as<std::wstring>();
459 else if (is<binding<bool>>(b))
460 return as<binding<bool>>(b).as<std::wstring>();
462 CASPAR_THROW_EXCEPTION(caspar_exception()
463 << msg_info(L"Couldn't stringify " + u16(value.type().name())));
466 boost::any add(const boost::any& lhs, boost::any& rhs)
468 auto l = as_binding(lhs);
469 auto r = as_binding(rhs);
472 if (is<binding<double>>(l) && is<binding<double>>(r))
473 return as<binding<double>>(l) + as<binding<double>>(r);
475 else if (is<binding<std::wstring>>(l) && is<binding<std::wstring>>(r))
476 return as<binding<std::wstring>>(l) + as<binding<std::wstring>>(r);
477 // mixed types to string and concatenated
479 return stringify(lhs) + stringify(rhs);
482 boost::any subtract(const boost::any& lhs, boost::any& rhs)
484 return require<double>(lhs) - require<double>(rhs);
487 boost::any less(const boost::any& lhs, boost::any& rhs)
489 return require<double>(lhs) < require<double>(rhs);
492 boost::any less_or_equal(const boost::any& lhs, boost::any& rhs)
494 return require<double>(lhs) <= require<double>(rhs);
497 boost::any greater(const boost::any& lhs, boost::any& rhs)
499 return require<double>(lhs) > require<double>(rhs);
502 boost::any greater_or_equal(const boost::any& lhs, boost::any& rhs)
504 return require<double>(lhs) >= require<double>(rhs);
507 boost::any equal(const boost::any& lhs, boost::any& rhs)
509 auto l = as_binding(lhs);
510 auto r = as_binding(rhs);
513 if (is<binding<double>>(l) && is<binding<double>>(r))
514 return as<binding<double>>(l) == as<binding<double>>(r);
516 else if (is<binding<std::wstring>>(l) && is<binding<std::wstring>>(r))
517 return as<binding<std::wstring>>(l) == as<binding<std::wstring>>(r);
520 return require<bool>(l) == require<bool>(r);
523 boost::any and_(const boost::any& lhs, boost::any& rhs)
525 return require<bool>(lhs) && require<bool>(rhs);
528 boost::any or_(const boost::any& lhs, boost::any& rhs)
530 return require<bool>(lhs) || require<bool>(rhs);
535 const binding<bool>& condition,
536 const binding<T>& true_value,
537 const binding<T>& false_value)
539 return when(condition).then(true_value).otherwise(false_value);
543 const boost::any& condition,
544 const boost::any& true_value,
545 const boost::any& false_value)
547 auto cond = require<bool>(condition);
548 auto t = as_binding(true_value);
549 auto f = as_binding(false_value);
552 if (is<binding<double>>(t) && is<binding<double>>(f))
553 return ternary(cond, as<binding<double>>(t), as<binding<double>>(f));
555 else if (is<binding<std::wstring>>(t) && is<binding<std::wstring>>(f))
558 as<binding<std::wstring>>(t),
559 as<binding<std::wstring>>(f));
562 return ternary(cond, require<bool>(t), require<bool>(f));
565 void resolve_operators(int precedence, std::vector<boost::any>& tokens)
567 for (int i = 0; i < tokens.size(); ++i)
569 auto& token = tokens.at(i);
574 auto op_token = as<op>(token);
576 if (op_token.precedence != precedence)
579 int index_after = i + 1;
580 auto& token_after = tokens.at(index_after);
582 switch (op_token.type)
584 case op::op_type::UNARY:
585 if (op_token.characters == L"unary-")
587 tokens.at(i) = negative(token_after);
589 else if (op_token.characters == L"!")
591 tokens.at(i) = not_(token_after);
594 tokens.erase(tokens.begin() + index_after);
597 case op::op_type::BINARY:
599 auto& token_before = tokens.at(i - 1);
601 if (op_token.characters == L"*")
602 token_before = multiply(token_before, token_after);
603 else if (op_token.characters == L"/")
604 token_before = divide(token_before, token_after);
605 else if (op_token.characters == L"%")
606 token_before = modulus(token_before, token_after);
607 else if (op_token.characters == L"+")
608 token_before = add(token_before, token_after);
609 else if (op_token.characters == L"-")
610 token_before = subtract(token_before, token_after);
611 else if (op_token.characters == L"<")
612 token_before = less(token_before, token_after);
613 else if (op_token.characters == L"<=")
614 token_before = less_or_equal(token_before, token_after);
615 else if (op_token.characters == L">")
616 token_before = greater(token_before, token_after);
617 else if (op_token.characters == L">=")
618 token_before = greater_or_equal(token_before, token_after);
619 else if (op_token.characters == L"==")
620 token_before = equal(token_before, token_after);
621 else if (op_token.characters == L"!=")
622 token_before = not_(equal(token_before, token_after));
623 else if (op_token.characters == L"&&")
624 token_before = and_(token_before, token_after);
625 else if (op_token.characters == L"||")
626 token_before = or_(token_before, token_after);
629 tokens.erase(tokens.begin() + i, tokens.begin() + i + 2);
633 case op::op_type::TERNARY:
634 if (op_token.characters == L"?")
636 auto& token_before = tokens.at(i - 1);
637 auto& token_colon_operator = tokens.at(i + 2);
639 if (as<op>(token_colon_operator).characters != L":")
640 CASPAR_THROW_EXCEPTION(caspar_exception() << msg_info(
641 L"Expected : as part of ternary expression"));
643 auto& token_false_value = tokens.at(i + 3);
644 token_before = ternary(
645 token_before, token_after, token_false_value);
646 tokens.erase(tokens.begin() + i, tokens.begin() + i + 4);
655 boost::any parse_expression(
656 std::wstring::const_iterator& cursor,
657 const std::wstring& str,
658 const variable_repository& var_repo)
660 std::vector<boost::any> tokens;
663 while (cursor != str.end())
665 wchar_t ch = next_non_whitespace(cursor, str, L"Expected expression");
679 tokens.push_back(parse_constant(cursor, str));
694 tokens.push_back(parse_operator(cursor, str));
697 tokens.push_back(parse_string_literal(cursor, str));
700 tokens.push_back(parse_parenthesis(cursor, str, var_repo));
706 tokens.push_back(parse_variable(cursor, str, var_repo));
715 CASPAR_THROW_EXCEPTION(caspar_exception()
716 << msg_info(L"Expected expression"));
720 while (tokens.size() > 1)
722 resolve_operators(precedence++, tokens);
725 return as_binding(tokens.at(0));
729 binding<std::wstring> parse_expression(
730 const std::wstring& str, const variable_repository& var_repo)
732 auto cursor = str.cbegin();
733 auto expr = parse_expression(cursor, str, var_repo);
735 if (is<binding<std::wstring>>(expr))
736 return as<binding<std::wstring>>(expr);
737 else if (is<binding<double>>(expr))
738 return as<binding<double>>(expr).as<std::wstring>();
740 CASPAR_THROW_EXCEPTION(caspar_exception() << msg_info(
741 L"parse_expression() Unsupported type "
742 + u16(expr.type().name())));