syntaxanalyzer.h

a basic interpreter free basic

#pragma once
/*
 * Class CSyntaxAnalyzer - Parse and execute
 */
class CSyntaxAnalyzer
{
private:
	// Runtime context
	CContext *m_Context;
	// Tokenlist from the lexer
	tokenlist_t *m_tokenlist;
	// Tokenlist iterator
	tokenlist_t::iterator m_tokenIterator;
	// Are we reading or creating variables (ie. in a DIM statement)
	bool m_Dim;
public:
	// Allow full construction
	CSyntaxAnalyzer(void);
	~CSyntaxAnalyzer(void);
	CSyntaxAnalyzer(CContext *Context, tokenlist_t *TokenList);

	// Set the runtime context (runtime context is required)
	void SetContext(CContext * Context);
	// Get the runtime context
	CContext * GetContext(void);

	// Set the token list for the current run
	void SetTokenList(tokenlist_t * TokenList);
	// Get the current token list
	tokenlist_t * GetTokenList(void);
	// Analyze a program statement
	void Analyze(void);
	// Wrapper for parsing an expression, for
	// defined functions
	float Expression(string strExpression);

private:
	// Parse a program statement
	void sProgramStatement(void);
	// Get a line number from the token stream
	int sLineNumber(void);
	// Get a statement from the token stream
	void sStatement(void);
	// Get a LET statement from the token stream
	bool sLetStatement(void);
	// Get a READ statement from the token stream
	bool sReadStatement(void);
	// Get a DATA statement from the token strea
	bool sDataStatement(void);
	// Get a PRINT statement from the token stream
	bool sPrintStatement(void);
	// Get a GOTO statement from the token stream
	bool sGotoStatement(void);
	// Get an IF THEN statement from the token stream
	bool sIfThenStatement(void);
	// Get a FOR statement from the input stream
	bool sForStatement(void);
	// Get a NEXT statement from the token stream
	bool sNextStatement(void);
	// Get a REM statement from the token stream
	bool sRemStatement(void);
	// Get a DIM statement from the token stream
	bool sDimStatement(void);
	// Get a DEF statement from the token stream
	bool sDefStatement(void);
	// Get a GOSUB statement from the token stream
	bool sGoSubStatement(void);
	// Get a RETURN statement from the token stream
	bool sReturnStatement(void);
	// Get a STOP statement from the token stream
	bool sStopStatement(void);
	// Get an END statement from the input stream
	bool sEndStatement(void);
	// Get a variable from the token stream
	CSymbol * sVariable(void);
	// Get a variable list from the token stream
	list<CSymbol *> * sVariableList(void);
	// Get a string from the token list
	string sString(void);
	// Get a list of evaluated expressions
	list<float> * sExpressionList(void);
	// Get a label/expression list from the token stream
	string sLabelExpressionList(void);
	// Get a label/express from the token stream, return it as a string
	string sLabelExpression(void);
	// Evaluate an expression
	float sExpression(void);
	// Get a signed term from the token stream
	float sSignedTerm(void);
	// Get a term from the token stream
	float sTerm(void);
	// Get a factor from the input stream
	float sFactor(void);
	// Return true and increment token iterator if the next operator is an exponentiation operator
	bool sExponentiationOperator(void);
	// Return with a character for +/- and increment iterator, or return NULL and leave iterator alone
	char sAdditiveOperator(void);
	// Return a mulop and increment iterator, or return NULL
	char sMultiplicativeOperator(void);
	// Return relop and increment iterator, or return NULL
	relop_t sRelationalOperator(void);
	// Return a constant from the token stream
	float sConstant(void);
	// Get an exponent portion of a constant (x.xEx)
	int sExponent(void);
	// Get an identifier from the token stream
	float sIdentifier(void);
	// Get an unsubscripted variable from the token stream
	string sUnsubscriptedVariable(void);
	// Get a subscripted variable from the token stream
	string sSubscriptedVariable(void);
	// Get a single digit from the token stream
	int sDigit(void);
	// Get a function from the token stream
	float sFunction(void);
	// Get a function identifier from the token stream
	string sFunctionIdentifier(void);
	// Returns -1 for left parenthesis, 1 for right parenthesis, and 0 for no parenthesis
	int sParenthesis(void);
};