tcl.lang
Class Expression

java.lang.Object
  tcl.lang.Expression

public class Expression
extends Object

This class handles Tcl expressions.

Field Summary

static int	AND
static int	BIT_AND
static int	BIT_NOT
static int	BIT_OR
static int	BIT_XOR
static int	CLOSE_PAREN
static int	COLON
static int	COMMA
static int	DIVIDE
static int	END
static int	EQUAL
static int	GEQ
static int	GREATER
static int	LEFT_SHIFT
static int	LEQ
static int	LESS
HashMap<String,tcl.lang.MathFunction>	mathFuncTable Maps name of function to its implementation
static int	MINUS
static int	MOD
static int	MULT
static int	NEQ
static int	NOT
static int	OPEN_PAREN
static String[]	operatorStrings Mapping from operator numbers to strings; used for error messages.
static int	OR
static int	PLUS
static int[]	precTable Precedence table.
static int	QUESTY
static int	RIGHT_SHIFT
static int	STREQ
static int	STRNEQ
static int	UNARY_MINUS
static int	UNARY_PLUS
static int	UNKNOWN
static int	VALUE

Constructor Summary

Expression()
Constructor.

Method Summary

static void	evalBinaryOperator(Interp interp, int operator, ExprValue value, ExprValue value2)
boolean	evalBoolean(Interp interp, String string) Evaluate an Tcl expression.
void	evalMathFunction(Interp interp, String funcName, ExprValue[] values, boolean releaseValues, ExprValue result) This procedure will lookup and invoke a math function given the name of the function and an array of ExprValue arguments.
void	evalSetResult(Interp interp, String string) Evaluate a Tcl expression and set the interp result to the value.
static void	evalUnaryOperator(Interp interp, int operator, ExprValue value)
static void	ExprParseObject(Interp interp, TclObject obj, ExprValue value) Given a TclObject, such as the result of a command or variable evaluation, fill in a ExprValue with the parsed result.
static void	ExprParseString(Interp interp, TclObject obj, ExprValue value) TclParseNumber -> ExprParseString Given a TclObject that contains a String to be parsed (from a command or variable subst), fill in an ExprValue based on the string's numeric value.
ExprValue	grabExprValue()
static void	IntegerTooLarge(Interp interp)
static boolean	looksLikeInt(String s, int len, int i, boolean whole) This procedure decides whether the leading characters of a string look like an integer or something else (such as a floating-point number or string).
void	releaseExprValue(ExprValue val)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

VALUE

public static final int VALUE

See Also:

Constant Field Values

OPEN_PAREN

public static final int OPEN_PAREN

See Also:

Constant Field Values

CLOSE_PAREN

public static final int CLOSE_PAREN

See Also:

Constant Field Values

COMMA

public static final int COMMA

See Also:

Constant Field Values

END

public static final int END

See Also:

Constant Field Values

UNKNOWN

public static final int UNKNOWN

See Also:

Constant Field Values

MULT

public static final int MULT

See Also:

Constant Field Values

DIVIDE

public static final int DIVIDE

See Also:

Constant Field Values

MOD

public static final int MOD

See Also:

Constant Field Values

PLUS

public static final int PLUS

See Also:

Constant Field Values

MINUS

public static final int MINUS

See Also:

Constant Field Values

LEFT_SHIFT

public static final int LEFT_SHIFT

See Also:

Constant Field Values

RIGHT_SHIFT

public static final int RIGHT_SHIFT

See Also:

Constant Field Values

LESS

public static final int LESS

See Also:

Constant Field Values

GREATER

public static final int GREATER

See Also:

Constant Field Values

LEQ

public static final int LEQ

See Also:

Constant Field Values

GEQ

public static final int GEQ

See Also:

Constant Field Values

EQUAL

public static final int EQUAL

See Also:

Constant Field Values

NEQ

public static final int NEQ

See Also:

Constant Field Values

BIT_AND

public static final int BIT_AND

See Also:

Constant Field Values

BIT_XOR

public static final int BIT_XOR

See Also:

Constant Field Values

BIT_OR

public static final int BIT_OR

See Also:

Constant Field Values

AND

public static final int AND

See Also:

Constant Field Values

OR

public static final int OR

See Also:

Constant Field Values

QUESTY

public static final int QUESTY

See Also:

Constant Field Values

COLON

public static final int COLON

See Also:

Constant Field Values

STREQ

public static final int STREQ

See Also:

Constant Field Values

STRNEQ

public static final int STRNEQ

See Also:

Constant Field Values

UNARY_MINUS

public static final int UNARY_MINUS

See Also:

Constant Field Values

UNARY_PLUS

public static final int UNARY_PLUS

See Also:

Constant Field Values

NOT

public static final int NOT

See Also:

Constant Field Values

BIT_NOT

public static final int BIT_NOT

See Also:

Constant Field Values

precTable

public static int[] precTable

Precedence table. The values for non-operator token types are ignored.

operatorStrings

public static String[] operatorStrings

Mapping from operator numbers to strings; used for error messages.

mathFuncTable

public HashMap<String,tcl.lang.MathFunction> mathFuncTable

Maps name of function to its implementation

Constructor Detail

Expression

public Expression()

Constructor.

Method Detail

evalSetResult

public void evalSetResult(Interp interp,
                          String string)
                   throws TclException

Evaluate a Tcl expression and set the interp result to the value.

Parameters:

interp - the context in which to evaluate the expression.

string - expression to evaluate.

Throws:

TclException - for malformed expressions.

evalBoolean

public boolean evalBoolean(Interp interp,
                           String string)
                    throws TclException

Evaluate an Tcl expression.

Parameters:

interp - the context in which to evaluate the expression.

string - expression to evaluate.

Returns:

the value of the expression in boolean.

Throws:

TclException - for malformed expressions.

IntegerTooLarge

public static void IntegerTooLarge(Interp interp)
                            throws TclException

Throws:

TclException

ExprParseObject

public static void ExprParseObject(Interp interp,
                                   TclObject obj,
                                   ExprValue value)
                            throws TclException

Given a TclObject, such as the result of a command or variable evaluation, fill in a ExprValue with the parsed result. If the TclObject already has an internal rep that is a numeric type, then no need to parse from the string rep. If the string rep is parsed into a numeric type, then update the internal rep of the object to the parsed value.

Throws:

TclException

ExprParseString

public static void ExprParseString(Interp interp,
                                   TclObject obj,
                                   ExprValue value)

TclParseNumber -> ExprParseString Given a TclObject that contains a String to be parsed (from a command or variable subst), fill in an ExprValue based on the string's numeric value. The value may be a floating-point, an integer, or a string. If the string value is converted to a numeric value, then update the internal rep of the TclObject.

Parameters:

interp - the context in which to evaluate the expression.

obj - the TclObject containing the string to parse.

value - the ExprValue object to save the parsed value in.

evalUnaryOperator

public static void evalUnaryOperator(Interp interp,
                                     int operator,
                                     ExprValue value)
                              throws TclException

Throws:

TclException

evalBinaryOperator

public static void evalBinaryOperator(Interp interp,
                                      int operator,
                                      ExprValue value,
                                      ExprValue value2)
                               throws TclException

Throws:

TclException

evalMathFunction

public void evalMathFunction(Interp interp,
                             String funcName,
                             ExprValue[] values,
                             boolean releaseValues,
                             ExprValue result)
                      throws TclException

This procedure will lookup and invoke a math function given the name of the function and an array of ExprValue arguments. Each ExprValue is released before the function exits. This method is intended to be used by other modules that may need to invoke a math function at runtime. It is assumed that the caller has checked the number of arguments, the type of the arguments will be adjusted before invocation if needed. The values argument can be null when there are no args to pass. The releaseValues argument should be true when the ExprValue objecys in the array should be released.

Throws:

TclException

looksLikeInt

public static boolean looksLikeInt(String s,
                                   int len,
                                   int i,
                                   boolean whole)

This procedure decides whether the leading characters of a string look like an integer or something else (such as a floating-point number or string). If the whole flag is true then the entire string must look like an integer.

Returns:

a boolean value indicating if the string looks like an integer.

grabExprValue

public final ExprValue grabExprValue()

releaseExprValue

public final void releaseExprValue(ExprValue val)