isc::dhcp::TokenPopAndBranchFalse Class Reference

Token that represents pop and branch if false. More...

#include <token.h>

Inheritance diagram for isc::dhcp::TokenPopAndBranchFalse:

Public Member Functions
	TokenPopAndBranchFalse (const unsigned target)
	Constructor.
virtual unsigned	evaluate (Pkt &pkt, ValueStack &values)
	Pops the top of stack which must be "false" or "true".
Public Member Functions inherited from isc::dhcp::TokenBranch
	TokenBranch (const unsigned target)
	Constructor.
unsigned	getTarget () const
	Returns branchtarget.
Public Member Functions inherited from isc::dhcp::Token
virtual	~Token ()
	Virtual destructor.
virtual unsigned	getLabel () const
	Return the label of this token.

Additional Inherited Members
Static Public Member Functions inherited from isc::dhcp::Token
static bool	toBool (std::string value)
	Coverts a (string) value to a boolean.
Protected Attributes inherited from isc::dhcp::TokenBranch
unsigned	target_

Detailed Description

Token that represents pop and branch if false.

Pop the op value, branch to a forward target when false. Can be used to implement the lazy "if" boolean operator i.e. evaluating either "then" or "else" branches (vs. strict the version which evaluates both).

Definition at line 1531 of file token.h.

Constructor & Destructor Documentation

TokenPopAndBranchFalse()

TokenPopAndBranchFalse::TokenPopAndBranchFalse

(

const unsigned

target

)

Constructor.

Parameters

target

the label to branch to

Exceptions

EvalParseError

when target is 0

Definition at line 1579 of file token.cc.

Member Function Documentation

evaluate()

unsigned TokenPopAndBranchFalse::evaluate ( Pkt & pkt, ValueStack & values )

virtual

Pops the top of stack which must be "false" or "true".

On "true" returns 0, on "false" return the branch target.

Parameters

pkt	(unused)
values	- stack of values (pop the boolean top value)

Exceptions

EvalBadStack	if there are less than 1 value on stack
EvalTypeError	if the top value on the stack is not either "true" or "false"

Returns

next label or 0 when means evaluate next token if any.

Reimplemented from isc::dhcp::TokenBranch.

Definition at line 1584 of file token.cc.

References isc::dhcp::EVAL_DBG_STACK, isc::dhcp::EVAL_DEBUG_POP_AND_BRANCH_FALSE, isc::dhcp::eval_logger, isc_throw, LOG_DEBUG, isc::dhcp::TokenBranch::target_, and isc::dhcp::Token::toBool().

Here is the call graph for this function:

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

• token.h
• token.cc