Uses of Class
org.rigwit.forth.XT

Packages that use XT

Package	Description
org.rigwit.forth	Forth Virtual Machine
org.rigwit.forth.words	Forth Word Sets.

Uses of XT in org.rigwit.forth

Fields in org.rigwit.forth declared as XT

Modifier and Type	Field and Description
XT	VM.lastXT A reference to the most recent user definition.

Methods in org.rigwit.forth that return XT

Modifier and Type	Method and Description
XT	VM.create() Parses the name from the input stream and create a new user definition XT adding it to the current word list.
XT	TypedStack.popXT() Pop an eXecution Token from the stack, returning it as an XT object.
XT	Dictionary.search(java.lang.String name) Search the dictionary for a given word name, returning the XT associated with the word name or null if not found.
XT	WordList.search(java.lang.String name) Search the word list for a given word, returning the associated execution token (XT) if found or null if the word is not found.

Methods in org.rigwit.forth with parameters of type XT

Modifier and Type	Method and Description
void	Dictionary.add(XT xt) Add a new Forth word to the current word list.
void	WordList.add(XT xt) Add a new word to the word list.
int	Kernel.colonDef(XT xt) The colon definition hander.
int	Kernel.constantDef(XT xt) The constant definition handler.
int	Kernel.definition(XT xt) Execute a user definition.
int	Kernel.doesDef(XT xt) The does definition handler.
boolean	XT.equals(XT other) Determine if this XT has the same behaviour as another XT.
int	Kernel.execute(XT xt) Execute the given XT, converting any Java based exceptions into the equivalent Forth Exceptions.
void	VM.execute(XT xt, java.lang.String name) Execute an XT and recover from any error it may report.
void	TypedStack.pushXT(XT xt) Push an eXecution Token onto the stack.
java.lang.String	Dictionary.search(XT xt) Search the dictionary for the word name that matches the given XT behaviour.
java.lang.String	WordList.search(XT target) Search the word list for the name of a given execution token (XT) behaviour, returning the associated word name if found or null if the XT is not found.
int	Kernel.variableDef(XT xt) The variable definition handler.

Uses of XT in org.rigwit.forth.words

Methods in org.rigwit.forth.words with parameters of type XT

Modifier and Type	Method and Description
void	CoreWords.abort(XT xt) Empty the data stack and perform the function of Quit, which includes emptying the return stack, without displaying a message.
void	CoreWords.abortQuote(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.abs(XT xt) Return the absolute value of top (n).
void	CoreWords.accept(XT xt) Receive a string of at most top (+n1) characters, placing it at next (c-addr), returns the actual number of character read.
void	CoreWords.actionOf(XT xt) Interpret: Stack{"name" -- xt} Skip leading spaces and parse name delimited by a space.
void	CoreWords.addressUnitBits(XT xt) Size of one address unit, in bits.
void	CoreWords.again(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.align(XT xt) If the data-space pointer is not aligned, reserve enough space to align it.
void	CoreWords.aligned(XT xt) a-addr is the first aligned address greater than or equal to addr.
void	CoreWords.allot(XT xt) If n is greater than zero, reserve n address units of data space.
void	CoreWords.and(XT xt)
void	CoreWords.base(XT xt) Return the address of the special variable containing the current number-conversion radix.
void	CoreWords.begin(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.bracketCompile(XT xt) Append the execution semantics of the definition represented by xt to the execution semantics of the current definition.
void	CoreWords.bracketTick(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.bufferColon(XT xt) Skip leading space delimiters.
void	ToolWords.bye(XT xt) Return control to the host operating system, if any.
void	CoreWords.carageReturn(XT xt) Cause subsequent output to appear at the beginning of the next line.
void	CoreWords.CASE(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.cellPlus(XT xt) Add the size in address units of a cell to a-addr1, giving a-addr2.
void	CoreWords.cells(XT xt) n2 is the size in address units of n1 cells.
void	CoreWords.character(XT xt) Return the first character of the next word in the input stream.
void	CoreWords.charComma(XT xt) Reserve space for one character in the data space and store char in the space.
void	CoreWords.charFetch(XT xt) Fetch the character (char) stored at top (c-addr).
void	CoreWords.charPlus(XT xt) Add the size in address units of a character to c-addr1, giving c-addr2.
void	CoreWords.chars(XT xt) n2 is the size in address units of n1 characters.
void	CoreWords.charStore(XT xt) Store the character next at top (c-addr).
void	CoreWords.colon(XT xt) Skip leading space delimiters.
void	CoreWords.colonNoname(XT xt) Stack[C]{ -- colon-sys} Stack[S]{ -- xt} Create an execution token xt, enter compilation state and start the current definition, producing colon-sys.
void	CoreWords.comma(XT xt) Reserve one cell of data space and store x in the cell.
void	CoreWords.comment(XT xt) Compile: Perform the execution semantics given below.
void	CoreWords.constant(XT xt) Skip leading space delimiters.
void	CoreWords.count(XT xt) Return the character string specification for the counted string stored at c-addr1.
void	CoreWords.countedString(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.create(XT xt) Skip leading space delimiters.
void	CoreWords.decimal(XT xt) Set the numeric conversion radix to ten (decimal).
int	CoreWords.defaultDefer(XT xt)
void	CoreWords.defer(XT xt) Stack{"name" -- } Skip leading space delimiters.
int	CoreWords.deferDef(XT xt)
void	CoreWords.depth(XT xt) Return the number of single-cell values contained in the data stack.
void	CoreWords.display(XT xt) Display top (n) in free field format.
void	CoreWords.displayRight(XT xt) Display next (n1) right aligned in a field top (n2) characters wide.
void	ToolWords.displayStack(XT xt) Copy and display the values currently on the data stack.
void	CoreWords.divide(XT xt) Divide next (n1) by top (n2), giving a single-cell quotient (n3).
void	CoreWords.divideMod(XT xt) Divide next (n1) by top (n2), giving the single-cell remainder (n3) and the single-cell quotient (n4).
void	CoreWords.DO(XT xt) Place a (do-sys) onto the control-flow stack and append the initialisation of a DO-loop control parameters with an index (top) and limit (next) to the current definition.
int	CoreWords.doAbortQuote(XT xt)
int	CoreWords.doActionOf(XT xt)
static int	CoreWords.doAgain(XT xt)
int	CoreWords.doCountedString(XT xt)
int	CoreWords.doDo(XT xt) The runtime action of a DO, set up the loop control parameters with index (top) and limit (next) and continue execution at the next instruction.
int	CoreWords.doDoes(XT xt)
int	CoreWords.doDotQuote(XT xt)
static int	CoreWords.doElse(XT xt) The runtime action of an ELSE, continue execution at the location specified by the XT.
int	CoreWords.doEndCase(XT xt)
static int	CoreWords.doEndOf(XT xt)
void	CoreWords.does(XT xt) Interpret: Interpretation semantics for this word are undefined.
int	CoreWords.doExit(XT xt) The runtime action for EXIT, drop the return address off of the return stack.
int	CoreWords.doI(XT xt) The runtime action for I, return a copy of the current (inner most) loop index.
int	CoreWords.doIF(XT xt) The runtime action of an IF, if all bits of top (x) are zero, continue execution at the location specified by the XT, otherwise continue with the next instruction.
int	CoreWords.doIs(XT xt)
int	CoreWords.doJ(XT xt) The runtime action for J, return a copy of the next-outer loop index.
int	CoreWords.doLeave(XT xt) The runtime action for LEAVE, discard the current loop control parameters and continue execution immediately following the innermost DO- or ?DO-loop.
int	CoreWords.doLiteral(XT xt)
int	CoreWords.doLoop(XT xt) The runtime action for LOOP, increment the loop index, if the index is equal to the limit discard the loop parameters and continue execution immediately following the loop, otherwise continue execution at the start of the loop.
int	CoreWords.doOf(XT xt)
int	CoreWords.doPlusLoop(XT xt) The runtime action for +LOOP, add top (n) to the loop index, if the index did not cross the boundary between the loop limit minus one and the loop limit, continue execution at the beginning of the or, otherwise discard the current loop control parameters and continue execution immediately following the loop.
int	CoreWords.doPostpone(XT xt)
int	CoreWords.doQueryDo(XT xt) The runtime action of a ?DO, if the index (top) is equal to the limit (next) continue execution at the first instruction after the loop, otherwise set up the loop control parameters and continue execution at the next instruction.
static int	CoreWords.doRepeat(XT xt)
int	CoreWords.doString(XT xt)
int	CoreWords.doTick(XT xt)
int	CoreWords.doTo(XT xt)
void	CoreWords.dotQuote(XT xt) Display a string immediately.
void	DoubleWords.doubleUnsigedLess(XT xt) ( ud2 ud1 -- flag )
int	CoreWords.doUnloop(XT xt) The runtime action for UNLOOP, discard the loop-control parameters for the current nesting level.
int	CoreWords.doUntil(XT xt)
int	CoreWords.doWhile(XT xt)
void	CoreWords.drop(XT xt) Remove the top value from the stack.
void	ToolWords.dump(XT xt) Display the contents of top (u) consecutive addresses starting at next (addr).
void	CoreWords.dup(XT xt) Duplicate top.
void	TestWords.echoOff(XT xt)
void	TestWords.echoOn(XT xt)
void	CoreWords.ELSE(XT xt) Put the location of a new unresolved forward reference (orig2) onto the control flow stack, appending a jump to the location specified by the resolution of the forward reference (orig2) to the current definition, resolving the forward reference (orig1) to the next instruction.
void	ToolWords.ELSE(XT xt)
void	CoreWords.emit(XT xt)
void	CoreWords.endCase(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.endOf(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	TestWords.endTest(XT xt)
void	CoreWords.environmentQuery(XT xt) c-addr is the address of a character string and u is the string's character count.
void	CoreWords.equal(XT xt) Return a flag indicating that next (x1) is bit-for-bit the same as top (x2).
void	CoreWords.erase(XT xt) If u is greater than zero, clear all bits in each of u consecutive address units of memory beginning at addr.
void	CoreWords.escapedString(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.evaluate(XT xt) Interpret the string (c-addr u).
void	CoreWords.execute(XT xt) Remove xt from the stack and perform the semantics identified by it.
void	CoreWords.exit(XT xt) Append the action to return control to the calling definition specified by nest-sys.
void	CoreWords.fetch(XT xt) Return the value (x) is the value stored at top (a-addr).
void	CoreWords.fill(XT xt) If u is greater than zero, store char in each of u consecutive characters of memory beginning at c-addr.
void	CoreWords.find(XT xt) Find the definition named in the counted string at c-addr.
void	CoreWords.FLOORED(XT xt) True if floored division is the default.
void	CoreWords.flooredMixedDivideMod(XT xt) Divide the double-cell next (d1) by top (n1), giving the floored quotient (n3) and the remainder (n2).
void	CoreWords.format(XT xt) Divide the double-cell top (ud1) by the current radix, returning the quotient (ud2) and converting the remainder into a character, adding it to the start of the pictured numeric output string.
void	CoreWords.formatEnd(XT xt) Drop the double-cell value (xd) and make the pictured numeric output string available as a character string (c-addr u).
void	CoreWords.formatS(XT xt) Convert all digits for the double-cell top (ud1) according to the rule for # until the quotient is zero, returning the zero quotient (ud2).
void	CoreWords.formatStart(XT xt) Initialise the pictured numeric output conversion process.
void	CoreWords.here(XT xt) addr is the data-space pointer.
void	CoreWords.hex(XT xt) Set contents of BASE to sixteen.
void	CoreWords.hold(XT xt) Add the character (top) to the start of the pictured numeric output string.
void	CoreWords.holdLength(XT xt) Size of the pictured numeric output string buffer, in characters.
void	CoreWords.holds(XT xt) Adds the string (c-addr u) to the start of the pictured numeric output string.
void	CoreWords.IF(XT xt) Put the location of a new unresolved forward reference (orig) onto the control flow stack, appending a branch if top is zero to the current definition.
void	ToolWords.IF(XT xt)
void	CoreWords.immediate(XT xt) Make the most recent definition an immediate word.
void	CoreWords.invert(XT xt) Invert all bits of top (x1), giving its logical inverse.
void	CoreWords.is(XT xt)
void	ToolWords.javaComment(XT xt)
void	CoreWords.key(XT xt) Receive one character (char), a member of the implementation-defined character set from the keyboard.
void	CoreWords.leave(XT xt) Place a forward reference for the LEAVE XT on the control-flow stack (underneath the do-sys) to be resolved by a LOOP or +LOOP and append the action to abort the current (innermost) DO- or ?DO-loop to the current definition.
void	CoreWords.leftBracket(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.less(XT xt) Return a flag indicating that next (n2) is less than top (n2).
void	CoreWords.lineComment(XT xt) Compile: Perform the execution semantics given below.
void	CoreWords.literal(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.loop(XT xt) Resolve the destination of all unresolved occurrences of LEAVE to continue execution at the following word, append the action to increment the loop index and continue execution at the start of the loop if the index is less than the limit, or continue with the following instruction if they are equal.
void	CoreWords.loopIndex(XT xt) Append the action of returning a copy of the inner loop index to the current definition.
void	CoreWords.lShift(XT xt) Return the logical left shift of top (u) bit-places on next (x1).
void	CoreWords.marker(XT xt) Skip leading space delimiters.
int	CoreWords.markerDef(XT xt)
void	CoreWords.max(XT xt) Return the grater of next (n1) and top (n2).
void	CoreWords.maxChar(XT xt) Parse the first character of the next word, placing it on the stack.
void	CoreWords.maxDouble(XT xt) Largest usable signed double number.
void	CoreWords.maxInteger(XT xt) Largest usable signed integer.
void	CoreWords.maxUnsigned(XT xt) Largest usable unsigned integer.
void	CoreWords.maxUnsignedDouble(XT xt) Largest usable unsigned double number.
void	CoreWords.min(XT xt) Return the lesser of next (n1) and top (n2).
void	CoreWords.mixedMultiply(XT xt) Multiply next (n) by top (n), returning the product (d).
void	CoreWords.mod(XT xt) Divide next (n1) by top (n2), giving the single-cell remainder (n3).
void	CoreWords.more(XT xt) Return a flag indicating that next (n2) is greater than top (n2).
void	CoreWords.move(XT xt) If u is greater than zero, copy the contents of u consecutive address units at addr1 to the u consecutive address units at addr2.
void	CoreWords.multiply(XT xt) Multiply next (n|u) by top (n|u), returning the product.
void	CoreWords.negate(XT xt) Negate top (n}, giving its arithmetic inverse (n).
void	ToolWords.nextArg(XT xt) Get the next argument from the command line, consuming it; if there is no argument left, return 0 0.
void	CoreWords.nip(XT xt) Drop the first item below the top of stack.
void	CoreWords.notEqual(XT xt) Return a flag indicating that next (x1) is not bit-for-bit the same as top (x2).
void	CoreWords.of(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.onePlus(XT xt) Add one to top (n|u).
void	CoreWords.oneSubtract(XT xt) Subtract one (1) from top (n|u}.
void	CoreWords.or(XT xt) Return the the bit-by-bit inclusive-or of next (x1) with top (x2).
void	CoreWords.outerLoopIndex(XT xt) Append the action of returning a copy of the next-outer loop index to the current definition.
void	CoreWords.over(XT xt) Place a copy of next on the top of the stack.
void	CoreWords.pad(XT xt) c-addr is the address of a transient region that can be used to hold data for intermediate processing.
void	CoreWords.padLength(XT xt) Size of the scratch area pointed to by PAD, in characters.
void	CoreWords.parse(XT xt) Parse ccc delimited by the delimiter char.
void	CoreWords.parseName(XT xt) Skip leading space delimiters.
void	CoreWords.pick(XT xt) Remove top (u), copy the uth element on the stack to the top of the stack.
void	CoreWords.plus(XT xt) Add top (n|u) to next (n|u), returning the sum.
void	CoreWords.plusLoop(XT xt) Resolve the destination of all unresolved occurrences of LEAVE to continue execution at the following word, append the action to add (top) to the loop index and continue execution at the start of the loop if the index does not cross the limit boundary, or continue with the following instruction.
void	CoreWords.plusStore(XT xt) Add n|u to the single-cell number at a-addr.
void	CoreWords.postpone(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.queryDo(XT xt) Place a (do-sys) onto the control-flow stack and append the initialisation of a ?DO-loop control parameters with an index (top) and limit (next) to the current definition.
void	CoreWords.queryDup(XT xt) Duplicate top if it is non-zero.
void	CoreWords.quit(XT xt) Empty the return stack, store zero in SOURCE-ID if it is present, make the user input device the input source, and enter interpretation state.
void	CoreWords.recurse(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.refill(XT xt) Attempt to fill the input buffer from the input source, returning a true flag if successful.
void	CoreWords.repeat(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.restoreInput(XT xt) Attempt to restore the input source specification to the state described by the stack, returning a flag indicating if the input was not restored.
void	CoreWords.returnFetch(XT xt) Return a copy of the value on the top of the return stack.
void	CoreWords.returnFrom(XT xt) Move the top of the return stack to the data stack.
void	CoreWords.returnSize(XT xt) Maximum size of the return stack, in cells.
void	CoreWords.rightBracket(XT xt) Enter compilation state.
void	CoreWords.roll(XT xt) Remove top (u), rotate the items on the stack bringing the uth item to the top.
void	CoreWords.rot(XT xt) Rotate the top three stack entries.
void	CoreWords.rShift(XT xt) Return the logical right shift of top (u) bit-places on next (x1).
void	CoreWords.saveInput(XT xt) Save the current state of the input source, for later use by RESTORE-INPUT, returning a variable number of items with the number of item on the top of the stack.
void	CoreWords.semicolon(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.sign(XT xt) If top (n) is negative, add a minus sign to the start of the pictured numeric output string.
void	CoreWords.singleToDouble(XT xt) Convert top (n) into a double-cell number with the same numerical value (d).
void	CoreWords.source(XT xt) Return a string (c-addr u) of the current input buffer.
void	CoreWords.sourceID(XT xt) Return an indication of the current input source, 0 for a user input device or -1 for a string.
void	CoreWords.stackSize(XT xt) Maximum size of the data stack, in cells.
void	TestWords.startTest(XT xt)
void	CoreWords.state(XT xt) a-addr is the address of a cell containing the compilation-state flag.
void	CoreWords.store(XT xt) Store next (x) at top (a-addr).
void	CoreWords.string(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.stringLength(XT xt) Maximum size of a counted string, in characters.
void	CoreWords.subtract(XT xt) Subtract top (n|u) from next (n|u), returning the difference.
void	CoreWords.swap(XT xt) Exchange the top two stack items.
void	CoreWords.symmetricMixedDivideRemainder(XT xt) Divide the double-cell next (d1) by top (n1), giving the symmetric quotient (n3) and the remainder (n2).
void	TestWords.test(XT xt)
void	TestWords.testing(XT xt)
void	TestWords.testPoint(XT xt)
void	CoreWords.THEN(XT xt) Resolve the forward reference (orig) using the location of the next instruction.
void	ToolWords.THEN(XT xt)
void	CoreWords.tick(XT xt) Read a name from the input stream and find the name in the dictionary, returning the corresponding XT.
void	CoreWords.timesDivide(XT xt) Multiply third (n1) by next (n2) producing the intermediate double-cell product which is divided by top (n3), returning the quotient (n4).
void	CoreWords.timesDivideMod(XT xt) Multiply third (n1) by next (n2) producing a double-cell intermediate product which is then divided by top (n3), giving the single-cell remainder (n4) and the single-cell quotient (n5).
void	CoreWords.to(XT xt) Interpret: Stack{i*x "name" -- } Skip leading spaces and parse name delimited by a space.
void	CoreWords.toBody(XT xt) a-addr is the data-field address corresponding to xt.
void	CoreWords.toIn(XT xt) Return the address of a special variable containing the offset, in characters, from the start of the input buffer to the start of the parse area.
void	CoreWords.toNumber(XT xt) ud2 is the unsigned result of converting the characters within the string specified by c-addr1 u1 into digits, using the number in BASE, and adding each into ud1 after multiplying ud1 by the number in BASE.
void	CoreWords.toR(XT xt) Move top (x) to the return stack.
void	CoreWords.tuck(XT xt) Copy top below next.
void	CoreWords.twoDivide(XT xt) Return the result of shifting top one bit toward the least-significant bit, leaving the most-significant bit unchanged.
void	CoreWords.twoDrop(XT xt) Drop cell pair x1 x2 from the stack.
void	CoreWords.twoDup(XT xt) Duplicate cell pair x1 x2.
void	CoreWords.twoFetch(XT xt) Fetch the cell pair x1 x2 stored at a-addr.
void	CoreWords.twoOver(XT xt) Copy cell pair x1 x2 to the top of the stack.
void	CoreWords.twoReturnFetch(XT xt) Copy a cell pair x1 x2 from the return stack.
void	CoreWords.twoRreturnFrom(XT xt) Transfer cell pair x1 x2 from the return stack.
void	CoreWords.twoStore(XT xt) Store the cell pair x1 x2 at a-addr, with x2 at a-addr and x1 at the next consecutive cell.
void	CoreWords.twoSwap(XT xt) Exchange the top two cell pairs.
void	CoreWords.twoTimes(XT xt) Return the result of shifting top (x1) one bit toward the most-significant bit, filling the vacated least-significant bit with zero.
void	CoreWords.twoToReturn(XT xt) Transfer cell pair x1 x2 to the return stack.
void	DoubleWords.twoVariable(XT xt)
void	CoreWords.type(XT xt) If top (u) is greater than zero, display the character string specified by next (c-addr) and top (u).
void	CoreWords.unloop(XT xt) Append the action for discarding the loop-control parameters of the innermost do-loop to the current definition.
void	CoreWords.unsigedMore(XT xt) Return a flag indicating that next (u1) is greater than top (u2).
void	CoreWords.unsigendDisplay(XT xt) Display top (u) in free field format.
void	CoreWords.unsignedDisplayRight(XT xt) Display next (u) right aligned in a field of top (n) characters wide.
void	CoreWords.unsignedLess(XT xt) Return a flag indicating that next (u1) is less than top (u2).
void	CoreWords.unsignedMixedDivideMod(XT xt) Divide the double-cell next (ud) by top (u1), giving the quotient (u3) and the remainder (u2).
void	CoreWords.unsignedMixedMultiply(XT xt) Multiply next (u1) by top (u2), giving an unsigned double-cell product (ud).
void	CoreWords.UNTIL(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.unused(XT xt) u is the amount of space remaining in the region addressed by HERE, in address units.
void	CoreWords.value(XT xt) Skip leading space delimiters.
int	CoreWords.valueDef(XT xt)
int	CoreWords.valueTo(XT xt)
void	CoreWords.variable(XT xt) Skip leading space delimiters.
void	CoreWords.WHILE(XT xt) Interpret: Interpretation semantics for this word are undefined.
void	CoreWords.within(XT xt) Perform a comparison of a test value n1|u1 with a lower limit n2|u2 and an upper limit n3|u3, returning true if either (n2|u2 < n3|u3 and (n2|u2 <= n1|u1 and n1|u1 < n3|u3)) or (n2|u2 > n3|u3 and (n2|u2 <= n1|u1 or n1|u1 < n3|u3)) is true, returning false otherwise.
void	CoreWords.word(XT xt) Skip leading delimiters.
void	CoreWords.xor(XT xt) Return the bit-by-bit exclusive-or of next (x1) with top (x2).
void	CoreWords.zeroEquals(XT xt) Return a flag indicating if top (x) is zero.
void	CoreWords.zeroLess(XT xt) Return a flag indicating that top (n) is less than zero.
void	CoreWords.zeroMore(XT xt) return a flag indicating that top (n) is greater than zero.
void	CoreWords.zeroNotEqual(XT xt) Return a flag indicating if top (x) is not zero.