#define END		(BINARY | 28)
				/* This lexeme represents the end of the
				 * string being parsed. Treating it as a
				 * binary operator follows the same logic as
				 * the CLOSE_PAREN lexeme and END pairs with
				 * START, in the same way that CLOSE_PAREN
				 * pairs with OPEN_PAREN. */
#define SEPARATOR      ( BINARY | 29)
#define ASSIGN         ( BINARY | 30)
				/* ASSIGN, like EXPON, is right associative,
 				 * and this distinction is coded directly in
				 * ParseExpr() */

/*
 * When ParseExpr() builds the parse tree it must choose which operands to
 * connect to which operators.  This is done according to operator precedence.
 * The greater an operator's precedence the greater claim it has to link to an
 * available operand.  The Precedence enumeration lists the precedence values
 * used by Tcl expression operators, from lowest to highest claim.  Each
 * precedence level is commented with the operators that hold that precedence.
 */

enum Precedence {
    PREC_END = 1,	/* END */
    PREC_START,		/* START */
    PREC_CLOSE_PAREN,	/* ")" */
    PREC_OPEN_PAREN,	/* "(" */
    PREC_COMMA,		/* "," */
    PREC_SEPARATOR,	/* ";" */
    PREC_ASSIGN,	/* "=" */
    PREC_CONDITIONAL,	/* "?", ":" */
    PREC_OR,		/* "||" */
    PREC_AND,		/* "&&" */
    PREC_BIT_OR,	/* "|" */
    PREC_BIT_XOR,	/* "^" */
    PREC_BIT_AND,	/* "&" */
    PREC_EQUAL,		/* "==", "!=", "eq", "ne", "in", "ni" */

    PREC_EQUAL,		/* STREQ */
    PREC_EQUAL,		/* STRNEQ */
    PREC_EXPON,		/* EXPON */
    PREC_EQUAL,		/* IN_LIST */
    PREC_EQUAL,		/* NOT_IN_LIST */
    PREC_CLOSE_PAREN,	/* CLOSE_PAREN */
    PREC_END,		/* END */
    PREC_SEPARATOR,	/* SEPARATOR */
    PREC_ASSIGN,	/* ASSIGN */
    /* Expansion room for more binary operators */
    0,
    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
    0,
    /* Unary operator lexemes */
    PREC_UNARY,		/* UNARY_PLUS */
    PREC_UNARY,		/* UNARY_MINUS */
    PREC_UNARY,		/* FUNCTION */

    INST_STR_EQ,	/* STREQ */
    INST_STR_NEQ,	/* STRNEQ */
    INST_EXPON,		/* EXPON */
    INST_LIST_IN,	/* IN_LIST */
    INST_LIST_NOT_IN,	/* NOT_IN_LIST */
    0,			/* CLOSE_PAREN */
    0,			/* END */
    0,			/* SEPARATOR */
    0,			/* ASSIGN */
    /* Expansion room for more binary operators */
    0,
    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
    0,
    /* Unary operator lexemes */
    INST_UPLUS,		/* UNARY_PLUS */
    INST_UMINUS,	/* UNARY_MINUS */
    0,			/* FUNCTION */

	VARIABLE	/* $ */,	MOD		/* % */,
	0		/* & or && */,	INVALID		/* ' */,
	OPEN_PAREN	/* ( */,	CLOSE_PAREN	/* ) */,
	0		/* * or ** */,	PLUS		/* + */,
	COMMA		/* , */,	MINUS		/* - */,
	0		/* . */,	DIVIDE		/* / */,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,			/* 0-9 */
	COLON		/* : */,	SEPARATOR	/* ; */,
	0		/* < or << or <= */,
	0		/* = or == */,
	0		/* > or >> or >= */,
	QUESTION	/* ? */,	INVALID		/* @ */,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,		/* A-M */
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,		/* N-Z */
	SCRIPT		/* [ */,	INVALID		/* \ */,
	INVALID		/* ] */,	BIT_XOR		/* ^ */,
	INVALID		/* _ */,	INVALID		/* ` */,

		    /*
		     * Right association rules for exponentiation.
		     */

		    if (lexeme == EXPON) {
			break;
		    }

		    /* Right association rules for assignment. */
		    if (lexeme == ASSIGN) {
			break;
		    }

		    /*
		     * Special association rules for the conditional
		     * operators. The "?" and ":" operators have equal
		     * precedence, but must be linked up in sensible pairs.
		     */

		 * they have a constant expression.
		 */

		if ((incompletePtr->lexeme == QUESTION)
			|| (incompletePtr->lexeme == FUNCTION)) {
		    nodes[complete].constant = incompletePtr->constant;
		}

		/*
		 * We declare all ASSIGN operators to be non-constant
		 * expressions because we do not want to optimize their
		 * variable-setting side effects out of existence.
		 */

		if (incompletePtr->lexeme == ASSIGN) {
		    incompletePtr->constant = 0;
		}

		if (incompletePtr->lexeme == START) {
		    /*
		     * Completing the START tree indicates we're done.
		     * Transfer the parse tree to the caller and return.
		     */

	return 1;

    case '=':
	if ((numBytes > 1) && (start[1] == '=')) {
	    *lexemePtr = EQUAL;
	    return 2;
	}
	*lexemePtr = ASSIGN;
	return 1;

    case '!':
	if ((numBytes > 1) && (start[1] == '=')) {
	    *lexemePtr = NEQ;
	    return 2;
	}

		 * progress (nested functions), save it in our unused "left"
		 * field for restoring later.
		 */

		nodePtr->left = numWords;
		numWords = 2;	/* Command plus one argument */
		break;
	    case SEPARATOR:
		TclEmitOpcode(INST_POP, envPtr);
		break;
	    }
	    case QUESTION:
		newJump = TclStackAlloc(interp, sizeof(JumpList));
		newJump->next = jumpPtr;
		jumpPtr = newJump;
		TclEmitForwardJump(envPtr, TCL_FALSE_JUMP, &jumpPtr->jump);
		break;

	    switch (nodePtr->lexeme) {
	    case START:
	    case QUESTION:
		if (convert && (nodePtr == rootPtr)) {
		    TclEmitOpcode(INST_TRY_CVT_TO_NUMERIC, envPtr);
		}
		break;
	    case ASSIGN:
		if (convert) {
		    /*
		     * Make sure we assign to a variable only values that
		     * have been numerically normalized in the expr way.
		     */
		    TclEmitOpcode(INST_TRY_CVT_TO_NUMERIC, envPtr);
		}
		TclEmitOpcode(INST_STORE_STK, envPtr);
		break;
	    case OPEN_PAREN:
	    case SEPARATOR:

		/* do nothing */
		break;
	    case FUNCTION:
		/*
		 * Use the numWords count we've kept to invoke the function
		 * command with the correct number of arguments.