#include <juce_Expression.h>
Classes | |
| class | Scope |
| struct | Symbol |
| class | Term |
| struct | Helpers |
Public Types | |
| enum | Type { constantType , functionType , operatorType , symbolType } |
Static Public Member Functions | |
| static Expression | symbol (const String &symbol) |
| static Expression | function (const String &functionName, const Array< Expression > ¶meters) |
| static Expression | parse (String::CharPointerType &stringToParse, String &parseError) |
Private Member Functions | |
| Expression (Term *) | |
Private Attributes | |
| ReferenceCountedObjectPtr< Term > | term |
Detailed Description
A class for dynamically evaluating simple numeric expressions.
This class can parse a simple C-style string expression involving floating point numbers, named symbols and functions. The basic arithmetic operations of +, -, *, / are supported, as well as parentheses, and any alphanumeric identifiers are assumed to be named symbols which will be resolved when the expression is evaluated.
Expressions which use identifiers and functions require a subclass of Expression::Scope to be supplied when evaluating them, and this object is expected to be able to resolve the symbol names and perform the functions that are used.
@tags{Core}
Member Enumeration Documentation
◆ Type
| enum juce::Expression::Type |
Expression type.
- See also
- Expression::getType()
| Enumerator | |
|---|---|
| constantType | |
| functionType | |
| operatorType | |
| symbolType | |
Constructor & Destructor Documentation
◆ Expression() [1/6]
| juce::Expression::Expression | ( | ) |
Creates a simple expression with a value of 0.
◆ ~Expression()
| juce::Expression::~Expression | ( | ) |
Destructor.
◆ Expression() [2/6]
| juce::Expression::Expression | ( | const Expression & | other | ) |
Creates a copy of an expression.
◆ Expression() [3/6]
|
noexcept |
Move constructor
◆ Expression() [4/6]
|
explicit |
Creates a simple expression with a specified constant value.
◆ Expression() [5/6]
Attempts to create an expression by parsing a string. Any errors are returned in the parseError argument provided.
◆ Expression() [6/6]
|
explicitprivate |
Member Function Documentation
◆ adjustedToGiveNewResult()
| Expression juce::Expression::adjustedToGiveNewResult | ( | double | targetValue, |
| const Scope & | scope ) const |
Attempts to return an expression which is a copy of this one, but with a constant adjusted to make the expression resolve to a target value.
E.g. if the expression is "x + 10" and x is 5, then asking for a target value of 8 will return the expression "x + 3". Obviously some expressions can't be reversed in this way, in which case they might just be adjusted by adding a constant to the original expression.
- Exceptions
-
Expression::EvaluationError
◆ evaluate() [1/3]
| double juce::Expression::evaluate | ( | ) | const |
◆ evaluate() [2/3]
Evaluates this expression, providing a scope that should be able to evaluate any symbols or functions that it uses. To find out about any errors during evaluation, use the other version of this method which takes a String parameter.
◆ evaluate() [3/3]
Evaluates this expression, providing a scope that should be able to evaluate any symbols or functions that it uses.
◆ findReferencedSymbols()
| void juce::Expression::findReferencedSymbols | ( | Array< Symbol > & | results, |
| const Scope & | scope ) const |
Returns a list of all symbols that may be needed to resolve this expression in the given scope.
◆ function()
|
static |
Returns an Expression which is a function call.
◆ getInput()
| Expression juce::Expression::getInput | ( | int | index | ) | const |
Retrieves one of the inputs to this expression.
- See also
- getNumInputs
◆ getNumInputs()
| int juce::Expression::getNumInputs | ( | ) | const |
Returns the number of inputs to this expression.
- See also
- getInput
◆ getSymbolOrFunction()
| String juce::Expression::getSymbolOrFunction | ( | ) | const |
If this expression is a symbol, function or operator, this returns its identifier.
◆ getType()
|
noexcept |
Returns the type of this expression.
◆ operator*()
| Expression juce::Expression::operator* | ( | const Expression & | other | ) | const |
Returns an expression which is a multiplication operation of two existing expressions.
◆ operator+()
| Expression juce::Expression::operator+ | ( | const Expression & | other | ) | const |
Returns an expression which is an addition operation of two existing expressions.
◆ operator-() [1/2]
| Expression juce::Expression::operator- | ( | ) | const |
Returns an expression which performs a negation operation on an existing expression.
◆ operator-() [2/2]
| Expression juce::Expression::operator- | ( | const Expression & | other | ) | const |
Returns an expression which is a subtraction operation of two existing expressions.
◆ operator/()
| Expression juce::Expression::operator/ | ( | const Expression & | other | ) | const |
Returns an expression which is a division operation of two existing expressions.
◆ operator=() [1/2]
| Expression & juce::Expression::operator= | ( | const Expression & | other | ) |
Copies another expression.
◆ operator=() [2/2]
|
noexcept |
Move assignment operator
◆ parse()
|
static |
Returns an Expression which parses a string from a character pointer, and updates the pointer to indicate where it finished.
The pointer is incremented so that on return, it indicates the character that follows the end of the expression that was parsed.
If there's a syntax error in parsing, the parseError argument will be set to a description of the problem.
◆ referencesSymbol()
Returns true if this expression makes use of the specified symbol. If a suitable scope is supplied, the search will dereference and recursively check all symbols, so that it can be determined whether this expression relies on the given symbol at any level in its evaluation. If the scope parameter is null, this just checks whether the expression contains any direct references to the symbol.
- Exceptions
-
Expression::EvaluationError
◆ symbol()
|
static |
Returns an Expression which is an identifier reference.
◆ toString()
| String juce::Expression::toString | ( | ) | const |
Returns a string version of the expression.
◆ usesAnySymbols()
| bool juce::Expression::usesAnySymbols | ( | ) | const |
Returns true if this expression contains any symbols.
◆ withRenamedSymbol()
| Expression juce::Expression::withRenamedSymbol | ( | const Symbol & | oldSymbol, |
| const String & | newName, | ||
| const Scope & | scope ) const |
Returns a copy of this expression in which all instances of a given symbol have been renamed.
Member Data Documentation
◆ term
|
private |
The documentation for this class was generated from the following files:
- /home/runner/work/lmms-fork/lmms-fork/plugins/CarlaBase/carla/source/modules/juce_core/maths/juce_Expression.h
- /home/runner/work/lmms-fork/lmms-fork/plugins/CarlaBase/carla/source/modules/juce_core/maths/juce_Expression.cpp
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