Parses incoming expression strings into a parse tree and generates an expression tree from the parse tree. More...

#include <Interpreter.h>

Public Member Functions
	Interpreter ()
	Constructor. More...

virtual	~Interpreter ()
	Destructor. More...

bool	delete_expression (const std::string &expression)
	Attempts to delete an expression from cache. More...

ExpressionTree	interpret (madara::knowledge::ThreadSafeContext &context, const std::string &input)
	Compiles an expression into an expression tree. More...

Static Public Member Functions
static bool	is_alphanumeric (char input)
	Checks a character to see if it is alphanumeric. More...

static bool	is_exponential (char input)
	Checks a character to see if it is in scientific format. More...

static bool	is_number (char input)
	Checks a character to see if it is a number. More...

static bool	is_operator (char input)
	Checks a character to see if it is a mathematical operator. More...

static bool	is_reserved_word (const std::string &input)
	Checks a given input for a reserved word literal. More...

static bool	is_string_literal (char input)
	Checks a character to see if it is a string literal. More...

static bool	is_whitespace (char input)
	Checks a character to see if it is whitespace. More...

Private Member Functions
void	handle_array (madara::knowledge::ThreadSafeContext &context, const std::string &input, std::string::size_type &i, Symbol &lastValidInput, bool &handled, int &accumulated_precedence,::std::list< Symbol > &list)
	Handles a parenthesis. More...

void	handle_for_loop (madara::knowledge::ThreadSafeContext &context, std::string &variable, const std::string &input, std::string::size_type &i, int &accumulated_precedence,::std::list< Symbol * > &list, Symbol *&returnableInput)
	extracts precondition, condition, postcondition, and body from input More...

void	handle_parenthesis (madara::knowledge::ThreadSafeContext &context, const std::string &input, std::string::size_type &i, Symbol &lastValidInput, bool &handled, int &accumulated_precedence,::std::list< Symbol > &list, bool build_argument_list=false)
	Handles a parenthesis. More...

void	main_loop (madara::knowledge::ThreadSafeContext &context, const std::string &input, std::string::size_type &i, Symbol &lastValidInput, bool &handled, int &accumulated_precedence,::std::list< Symbol > &list, bool build_argument_list=false)
	Inserts a variable into the tree. More...

void	number_insert (madara::knowledge::ThreadSafeContext &context, const std::string &input, std::string::size_type &i, int &accumulated_precedence,::std::list< Symbol * > &list, Symbol *&lastValidInput)
	Inserts a number into the tree. More...

void	precedence_insert (madara::knowledge::ThreadSafeContext &context, Symbol op,::std::list< Symbol > &list)
	Inserts a mathematical operator into the tree. More...

void	string_insert (char opener, madara::knowledge::ThreadSafeContext &context, const std::string &input, std::string::size_type &i, int &accumulated_precedence,::std::list< Symbol * > &list, Symbol *&lastValidInput)
	Inserts a variable into the tree. More...

void	system_call_insert (madara::knowledge::ThreadSafeContext &context, const std::string &input, std::string::size_type &i, int &accumulated_precedence,::std::list< Symbol * > &list, Symbol *&lastValidInput)
	Inserts a system call into the tree. More...

void	variable_insert (madara::knowledge::ThreadSafeContext &context, const std::string &input, std::string::size_type &i, int &accumulated_precedence,::std::list< Symbol * > &list, Symbol *&lastValidInput)
	Inserts a variable into the tree. More...

Private Attributes
ExpressionTreeMap	cache_
	Cache of expressions that have been previously compiled. More...

Detailed Description

Parses incoming expression strings into a parse tree and generates an expression tree from the parse tree.

This class plays the role of the "interpreter" in the Intepreter pattern. It also uses the Builder pattern to generate the nodes in the expression tree.

Definition at line 42 of file Interpreter.h.

Constructor & Destructor Documentation

madara::expression::Interpreter::Interpreter ( )

Constructor.

Definition at line 5069 of file Interpreter.cpp.

madara::expression::Interpreter::~Interpreter ( )

virtual

Destructor.

Definition at line 5074 of file Interpreter.cpp.

Member Function Documentation

bool madara::expression::Interpreter::delete_expression ( const std::string & expression )

inline

Attempts to delete an expression from cache.

Parameters

expression expression to erase from cache

Returns: true if the expression was deleted

Definition at line 82 of file Interpreter.inl.

void madara::expression::Interpreter::handle_array	(	madara::knowledge::ThreadSafeContext &	context,
		const std::string &	input,
		std::string::size_type &	i,
		Symbol *&	lastValidInput,
		bool &	handled,
		int &	accumulated_precedence,
		::std::list< Symbol * > &	list
	)

private

Handles a parenthesis.

Parameters

context	interpreter context
input	expression to compile
i	current position in expression
lastValidInput	last valid symbol that was read
list	list of symbols in tree that are free
handled	whether or not the pos should be incremented
accumulated_precedence	current precedence

Definition at line 6799 of file Interpreter.cpp.

void madara::expression::Interpreter::handle_for_loop	(	madara::knowledge::ThreadSafeContext &	context,
		std::string &	variable,
		const std::string &	input,
		std::string::size_type &	i,
		int &	accumulated_precedence,
		::std::list< Symbol * > &	list,
		Symbol *&	returnableInput
	)

private

extracts precondition, condition, postcondition, and body from input

Parameters

context	interpreter context
variable	name of the variable the for loop is based on
input	expression to compile
i	current position in expression
accumulated_precedence	current precedence
list	list of symbols to insert for loop into
returnableInput	used to interact with lastValidInput if an array reference is found

if we manage to find a delimiter but not its end, we're seeing an array reference with subtraction in it

Definition at line 5080 of file Interpreter.cpp.

void madara::expression::Interpreter::handle_parenthesis	(	madara::knowledge::ThreadSafeContext &	context,
		const std::string &	input,
		std::string::size_type &	i,
		Symbol *&	lastValidInput,
		bool &	handled,
		int &	accumulated_precedence,
		::std::list< Symbol * > &	list,
		bool	build_argument_list = `false`
	)

private

Handles a parenthesis.

Parameters

context	interpreter context
input	expression to compile
i	current position in expression
accumulated_precedence	current precedence
list	list of symbols in tree that are free
lastValidInput	last valid symbol that was read
handled	whether or not the pos should be incremented
build_argument_list	if true, focuses on building a list instead of an expression tree

Definition at line 6878 of file Interpreter.cpp.

madara::expression::ExpressionTree madara::expression::Interpreter::interpret	(	madara::knowledge::ThreadSafeContext &	context,
		const std::string &	input
	)

Compiles an expression into an expression tree.

Parameters

context	interpreter context
input	expression to compile

Returns: expression tree to evaluate

Exceptions

KarlException failure during interpret

Definition at line 6977 of file Interpreter.cpp.

bool madara::expression::Interpreter::is_alphanumeric ( char input )

inlinestatic

Checks a character to see if it is alphanumeric.

Parameters

input char to check

Returns: true if the input is alphanumeric

Definition at line 60 of file Interpreter.inl.

bool madara::expression::Interpreter::is_exponential ( char input )

inlinestatic

Checks a character to see if it is in scientific format.

Parameters

input char to check

Returns: true if the input is in scientific exponential format

Definition at line 37 of file Interpreter.inl.

bool madara::expression::Interpreter::is_number ( char input )

inlinestatic

Checks a character to see if it is a number.

Parameters

input char to check

Returns: true if the input is a number

Definition at line 30 of file Interpreter.inl.

bool madara::expression::Interpreter::is_operator ( char input )

inlinestatic

Checks a character to see if it is a mathematical operator.

Parameters

input char to check

Returns: true if the input is an operator

Definition at line 20 of file Interpreter.inl.

bool madara::expression::Interpreter::is_reserved_word ( const std::string & input )

inlinestatic

Checks a given input for a reserved word literal.

Parameters

input string to check

Returns: true if the input is an operator

Definition at line 44 of file Interpreter.inl.

bool madara::expression::Interpreter::is_string_literal ( char input )

inlinestatic

Checks a character to see if it is a string literal.

Parameters

input char to check

Returns: true if the input is an operator

Definition at line 52 of file Interpreter.inl.

bool madara::expression::Interpreter::is_whitespace ( char input )

inlinestatic

Checks a character to see if it is whitespace.

Parameters

input char to check

Returns: true if the input is whitespace

Definition at line 71 of file Interpreter.inl.

void madara::expression::Interpreter::main_loop	(	madara::knowledge::ThreadSafeContext &	context,
		const std::string &	input,
		std::string::size_type &	i,
		Symbol *&	lastValidInput,
		bool &	handled,
		int &	accumulated_precedence,
		::std::list< Symbol * > &	list,
		bool	build_argument_list = `false`
	)

private

Inserts a variable into the tree.

Parameters

context	interpreter context
input	expression to compile
i	current position in expression
accumulated_precedence	current precedence
list	list of symbols in tree that are free
lastValidInput	last valid symbol that was read
handled	whether or not the pos should be incremented
build_argument_list	if true, focuses on building a list instead of an expression tree

Definition at line 6282 of file Interpreter.cpp.

void madara::expression::Interpreter::number_insert	(	madara::knowledge::ThreadSafeContext &	context,
		const std::string &	input,
		std::string::size_type &	i,
		int &	accumulated_precedence,
		::std::list< Symbol * > &	list,
		Symbol *&	lastValidInput
	)

private

Inserts a number into the tree.

Parameters

context	thread safe context handle
input	expression to compile
i	current position in expression
accumulated_precedence	current precedence
list	list of symbols in tree that are free
lastValidInput	last valid symbol that was read

Definition at line 6020 of file Interpreter.cpp.

void madara::expression::Interpreter::precedence_insert	(	madara::knowledge::ThreadSafeContext &	context,
		Symbol *	op,
		::std::list< Symbol * > &	list
	)

private

Inserts a mathematical operator into the tree.

Parameters

context	thread safe context handle
op	symbol to insert
list	list of symbols in tree that are free

Definition at line 6097 of file Interpreter.cpp.

void madara::expression::Interpreter::string_insert	(	char	opener,
		madara::knowledge::ThreadSafeContext &	context,
		const std::string &	input,
		std::string::size_type &	i,
		int &	accumulated_precedence,
		::std::list< Symbol * > &	list,
		Symbol *&	lastValidInput
	)

private

Inserts a variable into the tree.

Parameters

opener	the opening string
context	interpreter context
input	expression to compile
i	current position in expression
accumulated_precedence	current precedence
list	list of symbols in tree that are free
lastValidInput	last valid symbol that was read

Definition at line 5687 of file Interpreter.cpp.

void madara::expression::Interpreter::system_call_insert	(	madara::knowledge::ThreadSafeContext &	context,
		const std::string &	input,
		std::string::size_type &	i,
		int &	accumulated_precedence,
		::std::list< Symbol * > &	list,
		Symbol *&	lastValidInput
	)

private

Inserts a system call into the tree.

Parameters

context	interpreter context
input	expression to compile
i	current position in expression
accumulated_precedence	current precedence
list	list of symbols in tree that are free
lastValidInput	last valid symbol that was read

Definition at line 5719 of file Interpreter.cpp.

void madara::expression::Interpreter::variable_insert	(	madara::knowledge::ThreadSafeContext &	context,
		const std::string &	input,
		std::string::size_type &	i,
		int &	accumulated_precedence,
		::std::list< Symbol * > &	list,
		Symbol *&	lastValidInput
	)

private

Inserts a variable into the tree.

Parameters

context	interpreter context
input	expression to compile
i	current position in expression
accumulated_precedence	current precedence
list	list of symbols in tree that are free
lastValidInput	last valid symbol that was read

Definition at line 5534 of file Interpreter.cpp.

Member Data Documentation

ExpressionTreeMap madara::expression::Interpreter::cache_

private

Cache of expressions that have been previously compiled.

Definition at line 288 of file Interpreter.h.

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

include/madara/expression/Interpreter.h
include/madara/expression/Interpreter.cpp
include/madara/expression/Interpreter.inl

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation