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...
Expression &	operator= (const Expression &expr)
	Copies an expression. More...
Expression &	operator= (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...

Static Public Member Functions
static std::pair< Expression, long >	parse_reference (const char *reference_str)
	Parses a string that starts with $ and represents a reference expression. 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]

expr

the expression to copy

Expression() [3/8]

PDI::Expression::Expression

(

Expression &&

expr

)

Moves an expression.

Parameters

[in]

expr

the 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]

expr

the 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]

expr

the string to parse

Expression() [6/8]

PDI::Expression::Expression

(

long

expr

)

Builds an expression that represents an integer.

Parameters

[in]

expr

the integer value

Expression() [7/8]

PDI::Expression::Expression

(

double

expr

)

Builds an expression that represents a float.

Parameters

[in]

expr

the flaot value

Expression() [8/8]

PDI::Expression::Expression

(

PC_tree_t

expr

)

Builds an expression that is parsed from PC_tree_t.

Parameters

[in]

expr

the 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]

expr

the expression to copy

Returns

*this

operator=() [2/2]

Expression& PDI::Expression::operator=

(

Expression &&

expr

)

Moves an expression.

Parameters

[in]

expr

the expression to move`

Returns

*this

operator+()

Expression PDI::Expression::operator+

(

const Expression &

expr

)

const

Summation operator of an expression.

Parameters

[in]

expr

the 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]

expr

the 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]

expr

the 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]

expr

the 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]

expr

the 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

ctx	the 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

ctx	the context in which to evaluate the expression
type	the type of the created Ref

Returns

the data reference

parse_reference()

static std::pair<Expression, long> PDI::Expression::parse_reference ( const char *  reference_str )

static

Parses a string that starts with $ and represents a reference expression.

Parameters

[in]

reference_str

string that represents a reference expression

Returns

resulted reference exrpession and number of bytes read from reference_str

---

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

• expression.h