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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,108 @@ | ||
| The following are changes from the original TinyExpr C library: | ||
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| - Compiles as C++17 code. | ||
| - `te_*` functions are now wrapped in a `te_parser` class. | ||
| - `te_interp()`, `te_compile()`, and `te_eval()` have been replaced with `te_parser::compile()`, `te_parser::evaluate()`, and `te_parser::set_variables_and_functions()`. | ||
| `set_variables_and_functions()` sets your list of custom functions and variables. `compile()` compiles and optimizes an expression. | ||
| Finally, `evaluate()` will use the already compiled expression and return its result. | ||
| `evaluate()` also has an overload that compiles and evaluates an expression in one call. | ||
| - Variable/function types (e.g., `TE_FUNCTION0`) have been removed; types are now deduced by the compiler. The available flags | ||
| for variables and functions are now just combinations of `TE_DEFAULT`, `TE_PURE`, and `TE_VARIADIC`. | ||
| - Formula parsing is now case insensitive. | ||
| - Added support for variadic functions (can accept 1-7 arguments); enabled through the `TE_VARIADIC` flag. | ||
| (Refer to the `AVERAGE()` function in `tinyexp.cpp` for an example.) | ||
| - Added support for parsing formulas in non-US format (e.g., `pow(2,2; 2)` instead of `pow(2.2, 2)`). Useful for when the program's locale is non-English. | ||
| (Refer to [Example 4](Examples.md) for a demonstration.) | ||
| - `te_expr` is now a derivable base class. This means that you can derive from `te_expr`, add new fields to that derived class (e.g., arrays, strings, even other classes) | ||
| and then use a custom class as an argument to the various function types that accept a `te_expr*` parameter. The function that you connect can then `dynamic_cast<>` | ||
| this argument and use its custom fields, thus greatly enhancing the functionality for these types of functions. | ||
| (See below for example.) | ||
| - Added exception support, where exceptions are thrown for situations like providing invalid separators. Calls to `compile` and `evaluate` should be wrapped in `try`...`catch` blocks. | ||
| - Memory management is handled by the `te_parser` class (you no longer need to call `te_free`). Also, replaced `malloc/free` with `new/delete`. | ||
| - Stricter type safety; uses `std::variant` (instead of unions) that support `double`, `const double*`, | ||
| and 16 specific function signatures (that will work with lambdas or function pointers). | ||
| Also uses `std::initializer` lists (instead of various pointer operations). | ||
| - Separate enums are now used between `te_expr` and `state`'s types and are more strongly typed. | ||
| - Added support for C and C++ style comments (`//` and `/**/`). | ||
| - `compile()` and `evaluate()` now accept `std::string_view`s, meaning that these functions can accept either `char*` or `std::string` arguments. | ||
| - Added support for `volatile`. | ||
| - Custom functions and variables can now contain periods in their names. | ||
| - Custom functions and variables can now start with an underscore. | ||
| - Custom functions and variables can now be removed. | ||
| - Added support for custom handlers to resolve unknown variables. | ||
| - Added new built-in functions: | ||
| - `and`: returns true (i.e., non-zero) if all conditions are true (accepts 1-7 arguments). | ||
| - `average`: returns the mean for a range of values (accepts 1-7 arguments). | ||
| - `bitlshift`: left shift operator. | ||
| Negative shift amount arguments (similar to *Excel*) is supported. | ||
| - `bitrshift`: right shift operator. | ||
| Negative shift amount arguments (similar to *Excel*) is supported. | ||
| - `cot`: returns the cotangent of an angle. | ||
| - `combin`: alias for `ncr()`, like the *Excel* function. | ||
| - `clamp`: constrains a value to a range. | ||
| - `fact`: alias for `fac()`, like the *Excel* function. | ||
| - `false`: returns `false` (i.e., `0`) in a boolean expression. | ||
| - `if`: if a value is true (i.e., non-zero), then returns the second argument; otherwise, returns the third argument. | ||
| - `ifs`: checks up to three conditions, returning the value corresponding to the first met condition. | ||
| - `max`: returns the maximum of a range of values (accepts 1-7 arguments). | ||
| - `min`: returns the minimum of a range of values (accepts 1-7 arguments). | ||
| - `mod`: returns remainder from a division. | ||
| - `nan`: returns `NaN` (i.e., Not-a-Number) in a boolean expression. | ||
| - `or`: returns true (i.e., non-zero) if any condition is true (accepts 1-7 arguments). | ||
| - `not`: returns logical negation of value. | ||
| - `permut`: alias for `npr()`, like the *Excel* function. | ||
| - `power`: alias for `pow()`, like the *Excel* function. | ||
| - `rand`: returns random number between `0` and `1`. | ||
| Note that this implementation uses the Mersenne Twister (`mt19937`) to generate random numbers. | ||
| - `round`: returns a number, rounded to a given decimal point. | ||
| (Decimal point is optional and defaults to `0`.) | ||
| Negative number-of-digits arguments (similar to *Excel*) is supported. | ||
| - `sign`: returns the sign of a number: `1` if positive, `-1` if negative, `0` if zero. | ||
| - `sum`: returns the sum of a list of values (accepts 1-7 arguments). | ||
| - `sqr`: returns a number squared. | ||
| - `tgamma`: returns gamma function of a specified value. | ||
| - `trunc`: returns the integer part of a number. | ||
| - `true`: returns `true` (i.e., `1`) in a boolean expression. | ||
| - Added new operators: | ||
| - `&` logical AND. | ||
| - `|` logical OR. | ||
| - `=` equal to. | ||
| - `==` equal to. | ||
| - `<>` not equal to. | ||
| - `!=` not equal to. | ||
| - `<` less than. | ||
| - `<=` less than or equal to. | ||
| - `>` greater than. | ||
| - `>=` greater than or equal to. | ||
| - `<<` left shift operator. | ||
| - `>>` right shift operator. | ||
| - `**` exponentiation (alias for `^`). | ||
| - `round` now supports negative number of digit arguments, similar to *Excel*. | ||
| For example, `ROUND(-50.55,-2)` will yield `-100`. | ||
| - Custom variables and functions are now stored in a `std::set` | ||
| (which can be easily accessed and updated via the new `get_variables_and_functions()/set_variables_and_functions()` functions). | ||
| - Added `is_function_used()` and `is_variable_used()` functions to see if a specific function or variable was used in the last parsed formula. | ||
| - Added `set_constant()` function to find and update the value of a constant (custom) variable by name. | ||
| (In this context, a constant is a variable mapped to a double value in the parser, rather than mapped to a runtime variable.) | ||
| - Added `get_constant()` function to return the value of a constant (custom) variable by name. | ||
| - Added `TE_FLOAT` preprocessor flag to use `float` instead of `double` for the parser's data type. | ||
| - Binary search (i.e., `std::set`) is now used to look up custom variables and functions (small optimization). | ||
| - You no longer need to specify the number of arguments for custom functions; it will deduce that for you. | ||
| - The position of an error when evaluating an expression is now managed by the `te_parser` class and accessible via `get_last_error_position()`. | ||
| - Some parsing errors can provide error messages available via `get_last_error_message()`. | ||
| - The position of aforementioned error is now 0-indexed (not 1-indexed); `te_parser::npos` indicates that there was no error. | ||
| - Added `success()` function to indicate if the last parse succeeded or not. | ||
| - Added `get_result()` function to get result from the last call to `evaluate` or `compile`. | ||
| - Now uses `std::numeric_limits` for math constants (instead of macro constants). | ||
| - Replaced C-style casts with `static_cast<>`. | ||
| - Replaced all macros with `constexpr`s and lambdas. | ||
| - Replaced custom binary search used for built-in function searching; `std::set` is used now. | ||
| - Now uses `nullptr` (instead of `0`). | ||
| - All data fields are now initialized. | ||
| - Added [Doxygen](https://github.com/doxygen/doxygen) comments. | ||
| - Removed `te_print()` debug function. | ||
| - Added `list_available_functions_and_variables()` function to display all available built-in and custom | ||
| functions and variables. | ||
| - Added `get_expression()` function to get the last formula used. | ||
| - Added `[[nodiscard]]` attributes to improve compile-time warnings. | ||
| - Added `constexpr` and `noexcept` for C++ optimization. |