PDI 1.2.0-alpha.2021-05-03.c9942bc

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PDI::Expression Class Reference

Public Member Functions

 Expression ()
 Builds an empty expression. More...
 
 Expression (const Expression &expr)
 Copies an expression. More...
 
 Expression (Expression &&expr)
 Moves an expression. More...
 
 Expression (const char *expr)
 Builds (i.e. More...
 
 Expression (const std::string &expr)
 Builds (i.e. More...
 
 Expression (long expr)
 Builds an expression that represents an integer. More...
 
 Expression (double expr)
 Builds an expression that represents a float. More...
 
 Expression (PC_tree_t expr)
 Builds an expression that is parsed from PC_tree_t. More...
 
 ~Expression ()
 Destroys an expression. More...
 
Expressionoperator= (const Expression &expr)
 Copies an expression. More...
 
Expressionoperator= (Expression &&expr)
 Moves an expression. More...
 
Expression operator+ (const Expression &expr) const
 Summation operator of an expression. More...
 
Expression operator* (const Expression &expr) const
 Multiplication operator of an expression. More...
 
Expression operator- (const Expression &expr) const
 Subtraction operator of an expression. More...
 
Expression operator/ (const Expression &expr) const
 Division operator of an expression. More...
 
Expression operator% (const Expression &expr) const
 Modulo operator of an expression. More...
 
 operator bool () const
 Checks whether this is an empty expression. More...
 
long to_long (Context &ctx) const
 Evaluates an expression as an integer. More...
 
double to_double (Context &ctx) const
 Evaluates an expression as a float. More...
 
std::string to_string (Context &ctx) const
 Evaluates an expression as a string. More...
 
Ref to_ref (Context &ctx) const
 Evaluates an expression as a data reference. More...
 
Ref to_ref (Context &ctx, const Datatype &type) const
 Evaluates an expression as a data reference. More...
 

Constructor & Destructor Documentation

◆ Expression() [1/8]

PDI::Expression::Expression ( )

Builds an empty expression.

No operation can be used on an empty expression, it can only be assigned to

◆ Expression() [2/8]

PDI::Expression::Expression ( const Expression expr)

Copies an expression.

Parameters
[in]exprthe expression to copy

◆ Expression() [3/8]

PDI::Expression::Expression ( Expression &&  expr)

Moves an expression.

Parameters
[in]exprthe expression to move

◆ Expression() [4/8]

PDI::Expression::Expression ( const char *  expr)

Builds (i.e.

parse) an expression from a string

The grammar of an expression is as follow:

/* parsing as a REFERENCE is preferred over OPERATION
parsing as an OPERATION is preferred over STRING_LITERAL
*/
EXPRESSION := REFERENCE | OPERATION | STRING_LITERAL
STRING_LITERAL := ( CHAR | '\' '\' | '\' '$'
| REFERENCE
| '$' '(' OPERATION ')'
)*
/* The operator descending precedence order is:
1. *, /, %: multiplication, division and modulo,
2. +, -: addition and subtraction,
3. <, >: less than and greater than,
4. =: equality,
5. &: logical AND,
6. |: logical OR.
*/
OPERATION := TERM ( OPERATOR TERM )*
TERM := ( INT_LITERAL | REFERENCE | '(' OPERATION ')' )
REFERENCE := '$' ( IREFERENCE | '{' IREFERENCE '}' )
IREFERENCE := ID ( '[' OPERATION ']' | '.' ID )*
INT_LITERAL ~= (0x)? [0-9]+ ( \. )
ID ~= [a-zA-Z_][a-zA-Z0-9_]*
CHAR ~= [^$\\]
OPERATOR ~= [|&=<>+\-\*/%]
Parameters
[in]exprthe string to parse

◆ Expression() [5/8]

PDI::Expression::Expression ( const std::string &  expr)

Builds (i.e.

parse) an expression from a string

The grammar of an expression is as follow:

/* parsing as a REFERENCE is preferred over OPERATION
parsing as an OPERATION is preferred over STRING_LITERAL
*/
EXPRESSION := REFERENCE | OPERATION | STRING_LITERAL
STRING_LITERAL := ( CHAR | '\' '\' | '\' '$'
| REFERENCE
| '$' '(' OPERATION ')'
)*
/* The operator descending precedence order is:
1. *, /, %: multiplication, division and modulo,
2. +, -: addition and subtraction,
3. <, >: less than and greater than,
4. =: equality,
5. &: logical AND,
6. |: logical OR.
*/
OPERATION := TERM ( OPERATOR TERM )*
TERM := ( INT_LITERAL | REFERENCE | '(' OPERATION ')' )
REFERENCE := '$' ( IREFERENCE | '{' IREFERENCE '}' )
IREFERENCE := ID ( '[' OPERATION ']' | '.' ID )*
INT_LITERAL ~= (0x)? [0-9]+ ( \. )
ID ~= [a-zA-Z_][a-zA-Z0-9_]*
CHAR ~= [^$\\]
OPERATOR ~= [|&=<>+\-\*/%]
Parameters
[in]exprthe string to parse

◆ Expression() [6/8]

PDI::Expression::Expression ( long  expr)

Builds an expression that represents an integer.

Parameters
[in]exprthe integer value

◆ Expression() [7/8]

PDI::Expression::Expression ( double  expr)

Builds an expression that represents a float.

Parameters
[in]exprthe flaot value

◆ Expression() [8/8]

PDI::Expression::Expression ( PC_tree_t  expr)

Builds an expression that is parsed from PC_tree_t.

Parameters
[in]exprthe PC_tree_t value

◆ ~Expression()

PDI::Expression::~Expression ( )

Destroys an expression.

Member Function Documentation

◆ operator=() [1/2]

Expression& PDI::Expression::operator= ( const Expression expr)

Copies an expression.

Parameters
[in]exprthe expression to copy
Returns
*this

◆ operator=() [2/2]

Expression& PDI::Expression::operator= ( Expression &&  expr)

Moves an expression.

Parameters
[in]exprthe expression to move`
Returns
*this

◆ operator+()

Expression PDI::Expression::operator+ ( const Expression expr) const

Summation operator of an expression.

Parameters
[in]exprthe expression to add
Returns
Expression as a result of sum

◆ operator*()

Expression PDI::Expression::operator* ( const Expression expr) const

Multiplication operator of an expression.

Parameters
[in]exprthe expression to multiply
Returns
Expression as a result of multiplication

◆ operator-()

Expression PDI::Expression::operator- ( const Expression expr) const

Subtraction operator of an expression.

Parameters
[in]exprthe expression to subtract
Returns
Expression as a result of subtraction

◆ operator/()

Expression PDI::Expression::operator/ ( const Expression expr) const

Division operator of an expression.

Parameters
[in]exprthe expression to divide
Returns
Expression as a result of division

◆ operator%()

Expression PDI::Expression::operator% ( const Expression expr) const

Modulo operator of an expression.

Parameters
[in]exprthe expression to use modulo
Returns
Expression as a result of modulo

◆ operator bool()

PDI::Expression::operator bool ( ) const

Checks whether this is an empty expression.

Returns
true if the expression is non-empty

◆ to_long()

long PDI::Expression::to_long ( Context ctx) const

Evaluates an expression as an integer.

Returns
the integer value

◆ to_double()

double PDI::Expression::to_double ( Context ctx) const

Evaluates an expression as a float.

Returns
the float value

◆ to_string()

std::string PDI::Expression::to_string ( Context ctx) const

Evaluates an expression as a string.

Returns
the string value

◆ to_ref() [1/2]

Ref PDI::Expression::to_ref ( Context ctx) const

Evaluates an expression as a data reference.

Parameters
ctxthe context in which to evaluate the expression
Returns
the data reference

◆ to_ref() [2/2]

Ref PDI::Expression::to_ref ( Context ctx,
const Datatype type 
) const

Evaluates an expression as a data reference.

Parameters
ctxthe context in which to evaluate the expression
typethe type of the created Ref
Returns
the data reference

The documentation for this class was generated from the following file: