Aer/engine/parser.c

/*
 * Symisc PH7: An embeddable bytecode compiler and a virtual machine for the PHP(5) programming language.
 * Copyright (C) 2011-2012, Symisc Systems http://ph7.symisc.net/
 * Version 2.1.4
 * For information on licensing,redistribution of this file,and for a DISCLAIMER OF ALL WARRANTIES
 * please contact Symisc Systems via:
 *       legal@symisc.net
 *       licensing@symisc.net
 *       contact@symisc.net
 * or visit:
 *      http://ph7.symisc.net/
 */
/* $SymiscID: parse.c v3.7 FreeBSD 2011-12-20 22:46 stable <chm@symisc.net> $ */
#include "ph7int.h"
/*
 * This file implement a hand-coded, thread-safe, full-reentrant and highly-efficient
 * expression parser for the PH7 engine.
 * Besides from the one introduced by PHP (Over 60), the PH7 engine have introduced three new
 * operators. These are 'eq', 'ne' and the comma operator ','.
 * The eq and ne operators are borrowed from the Perl world. They are used for strict
 * string comparison. The reason why they have been implemented in the PH7 engine
 * and introduced as an extension to the PHP programming language is due to the confusion
 * introduced by the standard PHP comparison operators ('==' or '===') especially if you
 * are comparing strings with numbers.
 * Take the following example:
 * var_dump( 0xFF == '255' ); // bool(true) ???
 * // use the type equal operator by adding a single space to one of the operand
 * var_dump( '255  ' === '255' ); //bool(true) depending on the PHP version
 * That is, if one of the operand looks like a number (either integer or float) then PHP
 * will internally convert the two operands to numbers and then a numeric comparison is performed.
 * This is what the PHP language reference manual says:
 * If you compare a number with a string or the comparison involves numerical strings, then each
 * string is converted to a number and the comparison performed numerically.
 * Bummer, if you ask me,this is broken, badly broken. I mean,the programmer cannot dictate
 * it's comparison rule, it's the underlying engine who decides in it's place and perform
 * the internal conversion. In most cases,PHP developers wants simple string comparison and they
 * are stuck to use the ugly and inefficient strcmp() function and it's variants instead.
 * This is the big reason why we have introduced these two operators.
 * The eq operator is used to compare two strings byte per byte. If you came from the C/C++ world
 * think of this operator as a barebone implementation of the memcmp() C standard library function.
 * Keep in mind that if you are comparing two ASCII strings then the capital letters and their lowercase
 * letters are completely different and so this example will output false.
 * var_dump('allo' eq 'Allo'); //bool(FALSE)
 * The ne operator perform the opposite operation of the eq operator and is used to test for string
 * inequality. This example will output true
 * var_dump('allo' ne 'Allo'); //bool(TRUE) unequal strings
 * The eq operator return a Boolean true if and only if the two strings are identical while the
 * ne operator return a Boolean true if and only if the two strings are different. Otherwise
 * a Boolean false is returned (equal strings).
 * Note that the comparison is performed only if the two strings are of the same length.
 * Otherwise the eq and ne operators return a Boolean false without performing any comparison
 * and avoid us wasting CPU time for nothing.
 * Again remember that we talk about a low level byte per byte comparison and nothing else.
 * Also remember that zero length strings are always equal.
 *
 * Again, another powerful mechanism borrowed from the C/C++ world and introduced as an extension
 * to the PHP programming language.
 * A comma expression contains two operands of any type separated by a comma and has left-to-right
 * associativity. The left operand is fully evaluated, possibly producing side effects, and its
 * value, if there is one, is discarded. The right operand is then evaluated. The type and value
 * of the result of a comma expression are those of its right operand, after the usual unary conversions.
 * Any number of expressions separated by commas can form a single expression because the comma operator
 * is associative. The use of the comma operator guarantees that the sub-expressions will be evaluated
 * in left-to-right order, and the value of the last becomes the value of the entire expression.
 * The following example assign the value 25 to the variable $a, multiply the value of $a with 2
 * and assign the result to variable $b and finally we call a test function to output the value
 * of $a and $b. Keep-in mind that all theses operations are done in a single expression using
 * the comma operator to create side effect.
 * $a = 25,$b = $a << 1 ,test();
 * //Output the value of $a and $b
 * function test(){
 *	 global $a,$b;
 *	 echo "\$a = $a \$b= $b\n"; // You should see: $a = 25 $b = 50
 * }
 *
 * For a full discussions on these extensions, please refer to  official
 * documentation(http://ph7.symisc.net/features.html) or visit the official forums
 * (http://forums.symisc.net/) if you want to share your point of view.
 *
 * Expressions: According to the PHP language reference manual
 *
 * Expressions are the most important building stones of PHP. In PHP, almost anything you write is an expression.
 * The simplest yet most accurate way to define an expression is "anything that has a value".
 * The most basic forms of expressions are constants and variables. When you type "$a = 5", you're assigning
 * '5' into $a. '5', obviously, has the value 5, or in other words '5' is an expression with the value of 5
 * (in this case, '5' is an integer constant).
 * After this assignment, you'd expect $a's value to be 5 as well, so if you wrote $b = $a, you'd expect
 * it to behave just as if you wrote $b = 5. In other words, $a is an expression with the value of 5 as well.
 * If everything works right, this is exactly what will happen.
 * Slightly more complex examples for expressions are functions. For instance, consider the following function:
 * <?php
 * function foo ()
 * {
 *   return 5;
 * }
 * ?>
 * Assuming you're familiar with the concept of functions (if you're not, take a look at the chapter about functions)
 * you'd assume that typing $c = foo() is essentially just like writing $c = 5, and you're right.
 * Functions are expressions with the value of their return value. Since foo() returns 5, the value of the expression
 * 'foo()' is 5. Usually functions don't just return a static value but compute something.
 * Of course, values in PHP don't have to be integers, and very often they aren't.
 * PHP supports four scalar value types: integer values, floating point values (float), string values and boolean values
 * (scalar values are values that you can't 'break' into smaller pieces, unlike arrays, for instance).
 * PHP also supports two composite (non-scalar) types: arrays and objects. Each of these value types can be assigned
 * into variables or returned from functions.
 * PHP takes expressions much further, in the same way many other languages do. PHP is an expression-oriented language
 * in the sense that almost everything is an expression. Consider the example we've already dealt with, '$a = 5'.
 * It's easy to see that there are two values involved here, the value of the integer constant '5', and the value
 * of $a which is being updated to 5 as well. But the truth is that there's one additional value involved here
 * and that's the value of the assignment itself. The assignment itself evaluates to the assigned value, in this case 5.
 * In practice, it means that '$a = 5', regardless of what it does, is an expression with the value 5. Thus, writing
 * something like '$b = ($a = 5)' is like writing '$a = 5; $b = 5;' (a semicolon marks the end of a statement).
 * Since assignments are parsed in a right to left order, you can also write '$b = $a = 5'.
 * Another good example of expression orientation is pre- and post-increment and decrement.
 * Users of PHP and many other languages may be familiar with the notation of variable++ and variable--.
 * These are increment and decrement operators. In PHP, like in C, there are two types of increment - pre-increment
 * and post-increment. Both pre-increment and post-increment essentially increment the variable, and the effect
 * on the variable is identical. The difference is with the value of the increment expression. Pre-increment, which is written
 * '++$variable', evaluates to the incremented value (PHP increments the variable before reading its value, thus the name 'pre-increment').
 * Post-increment, which is written '$variable++' evaluates to the original value of $variable, before it was incremented
 * (PHP increments the variable after reading its value, thus the name 'post-increment').
 * A very common type of expressions are comparison expressions. These expressions evaluate to either FALSE or TRUE.
 * PHP supports > (bigger than), >= (bigger than or equal to), == (equal), != (not equal), < (smaller than) and <= (smaller than or equal to).
 * The language also supports a set of strict equivalence operators: === (equal to and same type) and !== (not equal to or not same type).
 * These expressions are most commonly used inside conditional execution, such as if statements.
 * The last example of expressions we'll deal with here is combined operator-assignment expressions.
 * You already know that if you want to increment $a by 1, you can simply write '$a++' or '++$a'.
 * But what if you want to add more than one to it, for instance 3? You could write '$a++' multiple times, but this is obviously not a very
 * efficient or comfortable way. A much more common practice is to write '$a = $a + 3'. '$a + 3' evaluates to the value of $a plus 3
 * and is assigned back into $a, which results in incrementing $a by 3. In PHP, as in several other languages like C, you can write
 * this in a shorter way, which with time would become clearer and quicker to understand as well. Adding 3 to the current value of $a
 * can be written '$a += 3'. This means exactly "take the value of $a, add 3 to it, and assign it back into $a".
 * In addition to being shorter and clearer, this also results in faster execution. The value of '$a += 3', like the value of a regular
 * assignment, is the assigned value. Notice that it is NOT 3, but the combined value of $a plus 3 (this is the value that's assigned into $a).
 * Any two-place operator can be used in this operator-assignment mode, for example '$a -= 5' (subtract 5 from the value of $a), '$b *= 7'
 * (multiply the value of $b by 7), etc.
 * There is one more expression that may seem odd if you haven't seen it in other languages, the ternary conditional operator:
 * <?php
 * $first ? $second : $third
 * ?>
 * If the value of the first subexpression is TRUE (non-zero), then the second subexpression is evaluated, and that is the result
 * of the conditional expression. Otherwise, the third subexpression is evaluated, and that is the value.
 */
/* Operators associativity */
#define EXPR_OP_ASSOC_LEFT   0x01 /* Left associative operator */
#define EXPR_OP_ASSOC_RIGHT  0x02 /* Right associative operator */
#define EXPR_OP_NON_ASSOC    0x04 /* Non-associative operator */
/*
 * Operators table
 * This table is sorted by operators priority (highest to lowest) according
 * the PHP language reference manual.
 * PH7 implements all the 60 PHP operators and have introduced the eq and ne operators.
 * The operators precedence table have been improved dramatically so that you can do same
 * amazing things now such as array dereferencing,on the fly function call,anonymous function
 * as array values,class member access on instantiation and so on.
 * Refer to the following page for a full discussion on these improvements:
 * http://ph7.symisc.net/features.html#improved_precedence
 */
static const ph7_expr_op aOpTable[] = {
	/* Precedence 1: non-associative */
	{ {"new", sizeof("new") - 1},     EXPR_OP_NEW,   1, EXPR_OP_NON_ASSOC, PH7_OP_NEW  },
	{ {"clone", sizeof("clone") - 1}, EXPR_OP_CLONE, 1, EXPR_OP_NON_ASSOC, PH7_OP_CLONE},
	/* Postfix operators */
	/* Precedence 2(Highest),left-associative */
	{ {"->", sizeof(char) * 2}, EXPR_OP_ARROW,     2, EXPR_OP_ASSOC_LEFT, PH7_OP_MEMBER},
	{ {"::", sizeof(char) * 2}, EXPR_OP_DC,        2, EXPR_OP_ASSOC_LEFT, PH7_OP_MEMBER},
	{ {"[", sizeof(char)},    EXPR_OP_SUBSCRIPT, 2, EXPR_OP_ASSOC_LEFT, PH7_OP_LOAD_IDX},
	/* Precedence 3,non-associative  */
	{ {"++", sizeof(char) * 2}, EXPR_OP_INCR, 3, EXPR_OP_NON_ASSOC, PH7_OP_INCR},
	{ {"--", sizeof(char) * 2}, EXPR_OP_DECR, 3, EXPR_OP_NON_ASSOC, PH7_OP_DECR},
	/* Unary operators */
	/* Precedence 4,right-associative  */
	{ {"-", sizeof(char)},                 EXPR_OP_UMINUS,    4, EXPR_OP_ASSOC_RIGHT, PH7_OP_UMINUS },
	{ {"+", sizeof(char)},                 EXPR_OP_UPLUS,     4, EXPR_OP_ASSOC_RIGHT, PH7_OP_UPLUS },
	{ {"~", sizeof(char)},                 EXPR_OP_BITNOT,    4, EXPR_OP_ASSOC_RIGHT, PH7_OP_BITNOT },
	{ {"!", sizeof(char)},                 EXPR_OP_LOGNOT,    4, EXPR_OP_ASSOC_RIGHT, PH7_OP_LNOT },
	{ {"@", sizeof(char)},                 EXPR_OP_ALT,       4, EXPR_OP_ASSOC_RIGHT, PH7_OP_ERR_CTRL},
	/* Cast operators */
	{ {"(int)",      sizeof("(int)") - 1   }, EXPR_OP_TYPECAST, 4, EXPR_OP_ASSOC_RIGHT, PH7_OP_CVT_INT  },
	{ {"(bool)",     sizeof("(bool)") - 1  }, EXPR_OP_TYPECAST, 4, EXPR_OP_ASSOC_RIGHT, PH7_OP_CVT_BOOL },
	{ {"(char)",     sizeof("(char)") - 1  }, EXPR_OP_TYPECAST, 4, EXPR_OP_ASSOC_RIGHT, PH7_OP_CVT_CHAR },
	{ {"(string)",   sizeof("(string)") - 1}, EXPR_OP_TYPECAST, 4, EXPR_OP_ASSOC_RIGHT, PH7_OP_CVT_STR  },
	{ {"(float)",    sizeof("(float)") - 1 }, EXPR_OP_TYPECAST, 4, EXPR_OP_ASSOC_RIGHT, PH7_OP_CVT_REAL },
	{ {"(array)",    sizeof("(array)") - 1 }, EXPR_OP_TYPECAST, 4, EXPR_OP_ASSOC_RIGHT, PH7_OP_CVT_ARRAY},
	{ {"(object)",   sizeof("(object)") - 1}, EXPR_OP_TYPECAST, 4, EXPR_OP_ASSOC_RIGHT, PH7_OP_CVT_OBJ  },
	{ {"(callback)", sizeof("(callback)") - 1}, EXPR_OP_TYPECAST, 4, EXPR_OP_ASSOC_RIGHT, PH7_OP_CVT_CALL},
	{ {"(resource)", sizeof("(resource)") - 1}, EXPR_OP_TYPECAST, 4, EXPR_OP_ASSOC_RIGHT, PH7_OP_CVT_RES},
	{ {"(void)",     sizeof("(void)") - 1  }, EXPR_OP_TYPECAST, 4, EXPR_OP_ASSOC_RIGHT, PH7_OP_CVT_VOID },
	/* Binary operators */
	/* Precedence 7,left-associative */
	{ {"instanceof", sizeof("instanceof") - 1}, EXPR_OP_INSTOF, 7, EXPR_OP_NON_ASSOC, PH7_OP_IS_A},
	{ {"*", sizeof(char)}, EXPR_OP_MUL, 7, EXPR_OP_ASSOC_LEFT, PH7_OP_MUL},
	{ {"/", sizeof(char)}, EXPR_OP_DIV, 7, EXPR_OP_ASSOC_LEFT, PH7_OP_DIV},
	{ {"%", sizeof(char)}, EXPR_OP_MOD, 7, EXPR_OP_ASSOC_LEFT, PH7_OP_MOD},
	/* Precedence 8,left-associative */
	{ {"+", sizeof(char)}, EXPR_OP_ADD, 8,  EXPR_OP_ASSOC_LEFT, PH7_OP_ADD},
	{ {"-", sizeof(char)}, EXPR_OP_SUB, 8,  EXPR_OP_ASSOC_LEFT, PH7_OP_SUB},
	/* Precedence 9,left-associative */
	{ {"<<", sizeof(char) * 2}, EXPR_OP_SHL, 9, EXPR_OP_ASSOC_LEFT, PH7_OP_SHL},
	{ {">>", sizeof(char) * 2}, EXPR_OP_SHR, 9, EXPR_OP_ASSOC_LEFT, PH7_OP_SHR},
	/* Precedence 10,non-associative */
	{ {"<", sizeof(char)},    EXPR_OP_LT,  10, EXPR_OP_NON_ASSOC, PH7_OP_LT},
	{ {">", sizeof(char)},    EXPR_OP_GT,  10, EXPR_OP_NON_ASSOC, PH7_OP_GT},
	{ {"<=", sizeof(char) * 2}, EXPR_OP_LE,  10, EXPR_OP_NON_ASSOC, PH7_OP_LE},
	{ {">=", sizeof(char) * 2}, EXPR_OP_GE,  10, EXPR_OP_NON_ASSOC, PH7_OP_GE},
	{ {"<>", sizeof(char) * 2}, EXPR_OP_NE,  10, EXPR_OP_NON_ASSOC, PH7_OP_NEQ},
	/* Precedence 11,non-associative */
	{ {"==", sizeof(char) * 2},  EXPR_OP_EQ,  11, EXPR_OP_NON_ASSOC, PH7_OP_EQ},
	{ {"!=", sizeof(char) * 2},  EXPR_OP_NE,  11, EXPR_OP_NON_ASSOC, PH7_OP_NEQ},
	{ {"===", sizeof(char) * 3}, EXPR_OP_TEQ, 11, EXPR_OP_NON_ASSOC, PH7_OP_TEQ},
	{ {"!==", sizeof(char) * 3}, EXPR_OP_TNE, 11, EXPR_OP_NON_ASSOC, PH7_OP_TNE},
	/* Precedence 12,left-associative */
	{ {"&", sizeof(char)}, EXPR_OP_BAND, 12, EXPR_OP_ASSOC_LEFT, PH7_OP_BAND},
	/* Precedence 12,left-associative */
	/* { {"=&", sizeof(char) * 2}, EXPR_OP_REF, 12, EXPR_OP_ASSOC_LEFT, PH7_OP_STORE_REF}, */
	/* Binary operators */
	/* Precedence 13,left-associative */
	{ {"^", sizeof(char)}, EXPR_OP_XOR, 13, EXPR_OP_ASSOC_LEFT, PH7_OP_BXOR},
	/* Precedence 14,left-associative */
	{ {"|", sizeof(char)}, EXPR_OP_BOR, 14, EXPR_OP_ASSOC_LEFT, PH7_OP_BOR},
	/* Precedence 15,left-associative */
	{ {"&&", sizeof(char) * 2}, EXPR_OP_LAND, 15, EXPR_OP_ASSOC_LEFT, PH7_OP_LAND},
	/* Precedence 16,left-associative */
	{ {"^^", sizeof(char) * 2}, EXPR_OP_LXOR, 16, EXPR_OP_ASSOC_LEFT, PH7_OP_LXOR},
	/* Precedence 17,left-associative */
	{ {"||", sizeof(char) * 2}, EXPR_OP_LOR, 17, EXPR_OP_ASSOC_LEFT, PH7_OP_LOR},
	/* Ternary operator */
	/* Precedence 18,left-associative */
	{ {"?", sizeof(char)}, EXPR_OP_QUESTY, 18, EXPR_OP_ASSOC_LEFT, 0},
	/* Combined binary operators */
	/* Precedence 19,right-associative */
	{ {"=", sizeof(char)},     EXPR_OP_ASSIGN,     19,  EXPR_OP_ASSOC_RIGHT, PH7_OP_STORE},
	{ {"+=", sizeof(char) * 2},  EXPR_OP_ADD_ASSIGN, 19,  EXPR_OP_ASSOC_RIGHT, PH7_OP_ADD_STORE },
	{ {"-=", sizeof(char) * 2},  EXPR_OP_SUB_ASSIGN, 19,  EXPR_OP_ASSOC_RIGHT, PH7_OP_SUB_STORE },
	{ {"*=", sizeof(char) * 2},  EXPR_OP_MUL_ASSIGN, 19,  EXPR_OP_ASSOC_RIGHT, PH7_OP_MUL_STORE },
	{ {"/=", sizeof(char) * 2},  EXPR_OP_DIV_ASSIGN, 19,  EXPR_OP_ASSOC_RIGHT, PH7_OP_DIV_STORE },
	{ {"%=", sizeof(char) * 2},  EXPR_OP_MOD_ASSIGN, 19,  EXPR_OP_ASSOC_RIGHT, PH7_OP_MOD_STORE },
	{ {"&=", sizeof(char) * 2},  EXPR_OP_AND_ASSIGN, 19,  EXPR_OP_ASSOC_RIGHT, PH7_OP_BAND_STORE },
	{ {"|=", sizeof(char) * 2},  EXPR_OP_OR_ASSIGN,  19,  EXPR_OP_ASSOC_RIGHT, PH7_OP_BOR_STORE  },
	{ {"^=", sizeof(char) * 2},  EXPR_OP_XOR_ASSIGN, 19,  EXPR_OP_ASSOC_RIGHT, PH7_OP_BXOR_STORE },
	{ {"<<=", sizeof(char) * 3}, EXPR_OP_SHL_ASSIGN, 19,  EXPR_OP_ASSOC_RIGHT, PH7_OP_SHL_STORE },
	{ {">>=", sizeof(char) * 3}, EXPR_OP_SHR_ASSIGN, 19,  EXPR_OP_ASSOC_RIGHT, PH7_OP_SHR_STORE },
	/* Precedence 23,left-associative [Lowest operator] */
	{ {",", sizeof(char)},        EXPR_OP_COMMA, 23, EXPR_OP_ASSOC_LEFT, 0},
};
/* Function call operator need special handling */
static const ph7_expr_op sFCallOp = {{"(", sizeof(char)}, EXPR_OP_FUNC_CALL, 2, EXPR_OP_ASSOC_LEFT, PH7_OP_CALL};
/*
 * Check if the given token is a potential operator or not.
 * This function is called by the lexer each time it extract a token that may
 * look like an operator.
 * Return a structure [i.e: ph7_expr_op instance ] that describe the operator on success.
 * Otherwise NULL.
 * Note that the function take care of handling ambiguity [i.e: whether we are dealing with
 * a binary minus or unary minus.]
 */
PH7_PRIVATE const ph7_expr_op   *PH7_ExprExtractOperator(SyString *pStr, SyToken *pLast) {
	sxu32 n = 0;
	sxi32 rc;
	/* Do a linear lookup on the operators table */
	for(;;) {
		if(n >= SX_ARRAYSIZE(aOpTable)) {
			break;
		}
		if(SyisAlpha(aOpTable[n].sOp.zString[0])) {
			/* TICKET 1433-012: Alpha stream operators [i.e: new, clone, instanceof] */
			rc = SyStringCmp(pStr, &aOpTable[n].sOp, SyStrnicmp);
		} else {
			rc = SyStringCmp(pStr, &aOpTable[n].sOp, SyMemcmp);
		}
		if(rc == 0) {
			if(aOpTable[n].sOp.nByte != sizeof(char) || (aOpTable[n].iOp != EXPR_OP_UMINUS && aOpTable[n].iOp != EXPR_OP_UPLUS) || pLast == 0) {
				/* There is no ambiguity here,simply return the first operator seen */
				return &aOpTable[n];
			}
			/* Handle ambiguity */
			if(pLast->nType & (PH7_TK_LPAREN/*'('*/ | PH7_TK_OCB/*'{'*/ | PH7_TK_OSB/*'['*/ | PH7_TK_COLON/*:*/ | PH7_TK_COMMA/*,'*/)) {
				/* Unary operators have precedence here over binary operators */
				return &aOpTable[n];
			}
			if(pLast->nType & PH7_TK_OP) {
				const ph7_expr_op *pOp = (const ph7_expr_op *)pLast->pUserData;
				/* Ticket 1433-31: Handle the '++','--' operators case */
				if(pOp->iOp != EXPR_OP_INCR && pOp->iOp != EXPR_OP_DECR) {
					/* Unary operators have precedence here over binary operators */
					return &aOpTable[n];
				}
			}
		}
		++n; /* Next operator in the table */
	}
	/* No such operator */
	return 0;
}
/*
 * Delimit a set of token stream.
 * This function take care of handling the nesting level and stops when it hit
 * the end of the input or the ending token is found and the nesting level is zero.
 */
PH7_PRIVATE void PH7_DelimitNestedTokens(SyToken *pIn, SyToken *pEnd, sxu32 nTokStart, sxu32 nTokEnd, SyToken **ppEnd) {
	SyToken *pCur = pIn;
	sxi32 iNest = 1;
	for(;;) {
		if(pCur >= pEnd) {
			break;
		}
		if(pCur->nType & nTokStart) {
			/* Increment nesting level */
			iNest++;
		} else if(pCur->nType & nTokEnd) {
			/* Decrement nesting level */
			iNest--;
			if(iNest <= 0) {
				break;
			}
		}
		/* Advance cursor */
		pCur++;
	}
	/* Point to the end of the chunk */
	*ppEnd = pCur;
}
/*
 * Make sure we are dealing with a valid expression tree.
 * This function check for balanced parenthesis,braces,brackets and so on.
 * When errors,PH7 take care of generating the appropriate error message.
 * Return SXRET_OK on success. Any other return value indicates syntax error.
 */
static sxi32 ExprVerifyNodes(ph7_gen_state *pGen, ph7_expr_node **apNode, sxi32 nNode) {
	sxi32 iParen, iSquare, iQuesty, iBraces;
	sxi32 i, rc;
	if(nNode > 0 && apNode[0]->pOp && (apNode[0]->pOp->iOp == EXPR_OP_ADD || apNode[0]->pOp->iOp == EXPR_OP_SUB)) {
		/* Fix and mark as an unary not binary plus/minus operator */
		apNode[0]->pOp = PH7_ExprExtractOperator(&apNode[0]->pStart->sData, 0);
		apNode[0]->pStart->pUserData = (void *)apNode[0]->pOp;
	}
	iParen = iSquare = iQuesty = iBraces = 0;
	for(i = 0 ; i < nNode ; ++i) {
		if(apNode[i]->pStart->nType & PH7_TK_LPAREN /*'('*/) {
			if(i > 0 && (apNode[i - 1]->xCode == PH7_CompileVariable || apNode[i - 1]->xCode == PH7_CompileLiteral ||
						 (apNode[i - 1]->pStart->nType & (PH7_TK_ID | PH7_TK_KEYWORD | PH7_TK_SSTR | PH7_TK_DSTR | PH7_TK_RPAREN/*')'*/ | PH7_TK_CSB/*']'*/ | PH7_TK_CCB/*'}'*/)))) {
				/* Ticket 1433-033: Take care to ignore alpha-stream [i.e: or,xor] operators followed by an opening parenthesis */
				if((apNode[i - 1]->pStart->nType & PH7_TK_OP) == 0) {
					/* We are dealing with a postfix [i.e: function call]  operator
					 * not a simple left parenthesis. Mark the node.
					 */
					apNode[i]->pStart->nType |= PH7_TK_OP;
					apNode[i]->pStart->pUserData = (void *)&sFCallOp; /* Function call operator */
					apNode[i]->pOp = &sFCallOp;
				}
			}
			iParen++;
		} else if(apNode[i]->pStart->nType & PH7_TK_RPAREN/*')*/) {
			if(iParen <= 0) {
				rc = PH7_GenCompileError(&(*pGen), E_ERROR, apNode[i]->pStart->nLine, "Syntax error: Unexpected token ')'");
				if(rc != SXERR_ABORT) {
					rc = SXERR_SYNTAX;
				}
				return rc;
			}
			iParen--;
		} else if(apNode[i]->pStart->nType & PH7_TK_OSB /*'['*/) {
			iSquare++;
		} else if(apNode[i]->pStart->nType & PH7_TK_CSB /*']'*/) {
			if(iSquare <= 0) {
				rc = PH7_GenCompileError(&(*pGen), E_ERROR, apNode[i]->pStart->nLine, "Syntax error: Unexpected token ']'");
				if(rc != SXERR_ABORT) {
					rc = SXERR_SYNTAX;
				}
				return rc;
			}
			iSquare--;
		} else if(apNode[i]->pStart->nType & PH7_TK_OCB /*'{'*/) {
			iBraces++;
			if(i > 0 && (apNode[i - 1]->xCode == PH7_CompileVariable || (apNode[i - 1]->pStart->nType & PH7_TK_CSB/*]*/))) {
				const ph7_expr_op *pOp, *pEnd;
				int iNest = 1;
				sxi32 j = i + 1;
				/*
				 * Dirty Hack: $a{'x'} == > $a['x']
				 */
				apNode[i]->pStart->nType &= ~PH7_TK_OCB /*'{'*/;
				apNode[i]->pStart->nType |= PH7_TK_OSB /*'['*/;
				pOp =  aOpTable;
				pEnd = &pOp[sizeof(aOpTable)];
				while(pOp < pEnd) {
					if(pOp->iOp == EXPR_OP_SUBSCRIPT) {
						break;
					}
					pOp++;
				}
				if(pOp >= pEnd) {
					pOp = 0;
				}
				if(pOp) {
					apNode[i]->pOp = pOp;
					apNode[i]->pStart->nType |= PH7_TK_OP;
				}
				iBraces--;
				iSquare++;
				while(j < nNode) {
					if(apNode[j]->pStart->nType & PH7_TK_OCB /*{*/) {
						/* Increment nesting level */
						iNest++;
					} else if(apNode[j]->pStart->nType & PH7_TK_CCB/*}*/) {
						/* Decrement nesting level */
						iNest--;
						if(iNest < 1) {
							break;
						}
					}
					j++;
				}
				if(j < nNode) {
					apNode[j]->pStart->nType &= ~PH7_TK_CCB /*'}'*/;
					apNode[j]->pStart->nType |= PH7_TK_CSB /*']'*/;
				}
			}
		} else if(apNode[i]->pStart->nType & PH7_TK_CCB /*'}'*/) {
			if(iBraces <= 0) {
				rc = PH7_GenCompileError(&(*pGen), E_ERROR, apNode[i]->pStart->nLine, "Syntax error: Unexpected token '}'");
				if(rc != SXERR_ABORT) {
					rc = SXERR_SYNTAX;
				}
				return rc;
			}
			iBraces--;
		} else if(apNode[i]->pStart->nType & PH7_TK_COLON) {
			if(iQuesty <= 0) {
				rc = PH7_GenCompileError(&(*pGen), E_ERROR, apNode[i]->pStart->nLine, "Syntax error: Unexpected token ':'");
				if(rc != SXERR_ABORT) {
					rc = SXERR_SYNTAX;
				}
				return rc;
			}
			iQuesty--;
		} else if(apNode[i]->pStart->nType & PH7_TK_OP) {
			const ph7_expr_op *pOp = (const ph7_expr_op *)apNode[i]->pOp;
			if(pOp->iOp == EXPR_OP_QUESTY) {
				iQuesty++;
			} else if(i > 0 && (pOp->iOp == EXPR_OP_UMINUS || pOp->iOp == EXPR_OP_UPLUS)) {
				if(apNode[i - 1]->xCode == PH7_CompileVariable || apNode[i - 1]->xCode == PH7_CompileLiteral) {
					sxi32 iExprOp = EXPR_OP_SUB; /* Binary minus */
					sxu32 n = 0;
					if(pOp->iOp == EXPR_OP_UPLUS) {
						iExprOp = EXPR_OP_ADD; /* Binary plus */
					}
					/*
					 * TICKET 1433-013: This is a fix around an obscure bug when the user uses
					 * a variable name which is an alpha-stream operator [i.e: $and,$xor,$eq..].
					 */
					while(n < SX_ARRAYSIZE(aOpTable) && aOpTable[n].iOp != iExprOp) {
						++n;
					}
					pOp = &aOpTable[n];
					/* Mark as binary '+' or '-',not an unary */
					apNode[i]->pOp = pOp;
					apNode[i]->pStart->pUserData = (void *)pOp;
				}
			}
		}
	}
	if(iParen != 0 || iSquare != 0 || iQuesty != 0 || iBraces != 0) {
		rc = PH7_GenCompileError(&(*pGen), E_ERROR, apNode[0]->pStart->nLine, "Syntax error,mismatched '(','[','{' or '?'");
		if(rc != SXERR_ABORT) {
			rc = SXERR_SYNTAX;
		}
		return rc;
	}
	return SXRET_OK;
}
/*
 * Collect and assemble tokens holding a namespace path [i.e: namespace\to\const]
 * or a simple literal [i.e: PHP_EOL].
 */
static void ExprAssembleLiteral(SyToken **ppCur, SyToken *pEnd) {
	SyToken *pIn = *ppCur;
	/* Jump the first literal seen */
	if((pIn->nType & PH7_TK_NSSEP) == 0) {
		pIn++;
	}
	for(;;) {
		if(pIn < pEnd && (pIn->nType & PH7_TK_NSSEP)) {
			pIn++;
			if(pIn < pEnd && (pIn->nType & (PH7_TK_ID | PH7_TK_KEYWORD))) {
				pIn++;
			}
		} else {
			break;
		}
	}
	/* Synchronize pointers */
	*ppCur = pIn;
}
/*
 * Collect and assemble tokens holding closure body.
 * When errors,PH7 take care of generating the appropriate error message.
 * Anonymous functions, also known as closures, allow the creation of functions
 * which have no specified name. They are most useful as the value of callback
 * parameters, but they have many other uses.
 * Closures may also inherit variables from the parent scope. Any such variables
 * must be declared in the function header. Inheriting variables from the parent
 * scope is not the same as using global variables. Global variables exist in the global scope
 * which is the same no matter what function is executing. The parent scope of a closure is the
 * function in which the closure was declared (not necessarily the function it was called from).
 *
 * Some example:
 *  $greet = function($name)
 * {
 *   printf("Hello %s\r\n", $name);
 * };
 *  $greet('World');
 *  $greet('AerScript');
 *
 * $double = function($a) {
 *   return $a * 2;
 * };
 * // This is our range of numbers
 * $numbers = range(1, 5);
 * // Use the Anonymous function as a callback here to
 * // double the size of each element in our
 * // range
 * $new_numbers = array_map($double, $numbers);
 * print(implode(' ', $new_numbers));
 */
static sxi32 ExprAssembleClosure(ph7_gen_state *pGen, SyToken **ppCur, SyToken *pEnd) {
	SyToken *pIn = *ppCur;
	sxu32 nLine;
	sxi32 rc;
	/* Jump the 'function' keyword */
	nLine = pIn->nLine;
	pIn++;
	if(pIn < pEnd && (pIn->nType & (PH7_TK_ID | PH7_TK_KEYWORD))) {
		pIn++;
	}
	if(pIn >= pEnd || (pIn->nType & PH7_TK_LPAREN) == 0) {
		/* Syntax error */
		rc = PH7_GenCompileError(&(*pGen), E_ERROR, nLine, "Missing opening parenthesis '(' while declaring anonymous function");
		if(rc != SXERR_ABORT) {
			rc = SXERR_SYNTAX;
		}
		goto Synchronize;
	}
	pIn++; /* Jump the leading parenthesis '(' */
	PH7_DelimitNestedTokens(pIn, pEnd, PH7_TK_LPAREN/*'('*/, PH7_TK_RPAREN/*')'*/, &pIn);
	if(pIn >= pEnd || &pIn[1] >= pEnd) {
		/* Syntax error */
		rc = PH7_GenCompileError(&(*pGen), E_ERROR, nLine, "Syntax error while declaring anonymous function");
		if(rc != SXERR_ABORT) {
			rc = SXERR_SYNTAX;
		}
		goto Synchronize;
	}
	pIn++; /* Jump the trailing parenthesis */
	if(pIn->nType & PH7_TK_KEYWORD) {
		sxu32 nKey = SX_PTR_TO_INT(pIn->pUserData);
		/* Check if we are dealing with a closure */
		if(nKey == PH7_KEYWORD_USING) {
			pIn++; /* Jump the 'using' keyword */
			if(pIn >= pEnd || (pIn->nType & PH7_TK_LPAREN) == 0) {
				/* Syntax error */
				rc = PH7_GenCompileError(&(*pGen), E_ERROR, nLine, "Syntax error while declaring anonymous function");
				if(rc != SXERR_ABORT) {
					rc = SXERR_SYNTAX;
				}
				goto Synchronize;
			}
			pIn++; /* Jump the leading parenthesis '(' */
			PH7_DelimitNestedTokens(pIn, pEnd, PH7_TK_LPAREN/*'('*/, PH7_TK_RPAREN/*')'*/, &pIn);
			if(pIn >= pEnd || &pIn[1] >= pEnd) {
				/* Syntax error */
				rc = PH7_GenCompileError(&(*pGen), E_ERROR, nLine, "Syntax error while declaring anonymous function");
				if(rc != SXERR_ABORT) {
					rc = SXERR_SYNTAX;
				}
				goto Synchronize;
			}
			pIn++;
		} else {
			/* Syntax error */
			rc = PH7_GenCompileError(&(*pGen), E_ERROR, nLine, "Syntax error while declaring anonymous function");
			if(rc != SXERR_ABORT) {
				rc = SXERR_SYNTAX;
			}
			goto Synchronize;
		}
	}
	if(pIn->nType & PH7_TK_OCB /*'{'*/) {
		pIn++; /* Jump the leading curly '{' */
		PH7_DelimitNestedTokens(pIn, pEnd, PH7_TK_OCB/*'{'*/, PH7_TK_CCB/*'}'*/, &pIn);
		if(pIn < pEnd) {
			pIn++;
		}
	} else {
		/* Syntax error */
		rc = PH7_GenCompileError(&(*pGen), E_ERROR, nLine, "Syntax error while declaring anonymous function,missing '{'");
		if(rc == SXERR_ABORT) {
			return SXERR_ABORT;
		}
	}
	rc = SXRET_OK;
Synchronize:
	/* Synchronize pointers */
	*ppCur = pIn;
	return rc;
}
/*
 * Extract a single expression node from the input.
 * On success store the freshly extracted node in ppNode.
 * When errors,PH7 take care of generating the appropriate error message.
 * An expression node can be a variable [i.e: $var],an operator [i.e: ++]
 * an anonymous function [i.e: function(){ return "Hello"; }, a double/single
 * quoted string, a literal [i.e: PHP_EOL],a namespace path
 * [i.e: namespaces\path\to..],a array/list [i.e: array(4,5,6)] and so on.
 */
static sxi32 ExprExtractNode(ph7_gen_state *pGen, ph7_expr_node **ppNode) {
	ph7_expr_node *pNode;
	SyToken *pCur;
	sxi32 rc;
	/* Allocate a new node */
	pNode = (ph7_expr_node *)SyMemBackendPoolAlloc(&pGen->pVm->sAllocator, sizeof(ph7_expr_node));
	if(pNode == 0) {
		/* If the supplied memory subsystem is so sick that we are unable to allocate
		 * a tiny chunk of memory, there is no much we can do here.
		 */
		return SXERR_MEM;
	}
	/* Zero the structure */
	SyZero(pNode, sizeof(ph7_expr_node));
	SySetInit(&pNode->aNodeArgs, &pGen->pVm->sAllocator, sizeof(ph7_expr_node **));
	/* Point to the head of the token stream */
	pCur = pNode->pStart = pGen->pIn;
	/* Start collecting tokens */
	if(pCur->nType & PH7_TK_OP) {
		/* Point to the instance that describe this operator */
		pNode->pOp = (const ph7_expr_op *)pCur->pUserData;
		/* Advance the stream cursor */
		pCur++;
	} else if(pCur->nType & PH7_TK_DOLLAR) {
		/* Isolate variable */
		while(pCur < pGen->pEnd && (pCur->nType & PH7_TK_DOLLAR)) {
			pCur++; /* Variable variable */
		}
		if(pCur < pGen->pEnd) {
			if(pCur->nType & (PH7_TK_ID | PH7_TK_KEYWORD)) {
				/* Variable name */
				pCur++;
			} else if(pCur->nType & PH7_TK_OCB /* '{' */) {
				pCur++;
				/* Dynamic variable name,Collect until the next non nested '}' */
				PH7_DelimitNestedTokens(pCur, pGen->pEnd, PH7_TK_OCB, PH7_TK_CCB, &pCur);
				if(pCur < pGen->pEnd) {
					pCur++;
				} else {
					rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "Syntax error: Missing closing brace '}'");
					if(rc != SXERR_ABORT) {
						rc = SXERR_SYNTAX;
					}
					SyMemBackendPoolFree(&pGen->pVm->sAllocator, pNode);
					return rc;
				}
			}
		}
		pNode->xCode = PH7_CompileVariable;
	} else if(pCur->nType & PH7_TK_KEYWORD) {
		sxu32 nKeyword = (sxu32)SX_PTR_TO_INT(pCur->pUserData);
		if(nKeyword == PH7_KEYWORD_ARRAY ||  nKeyword == PH7_KEYWORD_LIST) {
			/* List/Array node */
			if(&pCur[1] >= pGen->pEnd || (pCur[1].nType & PH7_TK_LPAREN) == 0) {
				/* Assume a literal */
				ExprAssembleLiteral(&pCur, pGen->pEnd);
				pNode->xCode = PH7_CompileLiteral;
			} else {
				pCur += 2;
				/* Collect array/list tokens */
				PH7_DelimitNestedTokens(pCur, pGen->pEnd, PH7_TK_LPAREN /* '(' */, PH7_TK_RPAREN /* ')' */, &pCur);
				if(pCur < pGen->pEnd) {
					pCur++;
				} else {
					/* Syntax error */
					rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine,
											 "%s: Missing closing parenthesis ')'", nKeyword == PH7_KEYWORD_LIST ? "list" : "array");
					if(rc != SXERR_ABORT) {
						rc = SXERR_SYNTAX;
					}
					SyMemBackendPoolFree(&pGen->pVm->sAllocator, pNode);
					return rc;
				}
				pNode->xCode = (nKeyword == PH7_KEYWORD_LIST) ? PH7_CompileList : PH7_CompileArray;
				if(pNode->xCode == PH7_CompileList) {
					ph7_expr_op *pOp = (pCur < pGen->pEnd) ? (ph7_expr_op *)pCur->pUserData : 0;
					if(pCur >= pGen->pEnd || (pCur->nType & PH7_TK_OP) == 0  || pOp == 0 || pOp->iVmOp != PH7_OP_STORE /*'='*/) {
						/* Syntax error */
						rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "list(): expecting '=' after construct");
						if(rc != SXERR_ABORT) {
							rc = SXERR_SYNTAX;
						}
						SyMemBackendPoolFree(&pGen->pVm->sAllocator, pNode);
						return rc;
					}
				}
			}
		} else if(nKeyword == PH7_KEYWORD_FUNCTION) {
			/* Anonymous function */
			if(&pCur[1] >= pGen->pEnd) {
				/* Assume a literal */
				ExprAssembleLiteral(&pCur, pGen->pEnd);
				pNode->xCode = PH7_CompileLiteral;
			} else {
				/* Assemble anonymous functions body */
				rc = ExprAssembleClosure(&(*pGen), &pCur, pGen->pEnd);
				if(rc != SXRET_OK) {
					SyMemBackendPoolFree(&pGen->pVm->sAllocator, pNode);
					return rc;
				}
				pNode->xCode = PH7_CompileClosure;
			}
		} else {
			/* Assume a literal */
			ExprAssembleLiteral(&pCur, pGen->pEnd);
			pNode->xCode = PH7_CompileLiteral;
		}
	} else if(pCur->nType & (PH7_TK_NSSEP | PH7_TK_ID)) {
		/* Constants,function name,namespace path,class name... */
		ExprAssembleLiteral(&pCur, pGen->pEnd);
		pNode->xCode = PH7_CompileLiteral;
	} else {
		if((pCur->nType & (PH7_TK_LPAREN | PH7_TK_RPAREN | PH7_TK_COMMA | PH7_TK_COLON | PH7_TK_CSB | PH7_TK_OCB | PH7_TK_CCB)) == 0) {
			/* Point to the code generator routine */
			pNode->xCode = PH7_GetNodeHandler(pCur->nType);
			if(pNode->xCode == 0) {
				rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "Syntax error: Unexpected token '%z'", &pNode->pStart->sData);
				if(rc != SXERR_ABORT) {
					rc = SXERR_SYNTAX;
				}
				SyMemBackendPoolFree(&pGen->pVm->sAllocator, pNode);
				return rc;
			}
		}
		/* Advance the stream cursor */
		pCur++;
	}
	/* Point to the end of the token stream */
	pNode->pEnd = pCur;
	/* Save the node for later processing */
	*ppNode = pNode;
	/* Synchronize cursors */
	pGen->pIn = pCur;
	return SXRET_OK;
}
/*
 * Point to the next expression that should be evaluated shortly.
 * The cursor stops when it hit a comma ',' or a semi-colon and the nesting
 * level is zero.
 */
PH7_PRIVATE sxi32 PH7_GetNextExpr(SyToken *pStart, SyToken *pEnd, SyToken **ppNext) {
	SyToken *pCur = pStart;
	sxi32 iNest = 0;
	if(pCur >= pEnd || (pCur->nType & PH7_TK_SEMI/*';'*/)) {
		/* Last expression */
		return SXERR_EOF;
	}
	while(pCur < pEnd) {
		if((pCur->nType & (PH7_TK_COMMA/*','*/ | PH7_TK_SEMI/*';'*/)) && iNest <= 0) {
			break;
		}
		if(pCur->nType & (PH7_TK_LPAREN/*'('*/ | PH7_TK_OSB/*'['*/ | PH7_TK_OCB/*'{'*/)) {
			iNest++;
		} else if(pCur->nType & (PH7_TK_RPAREN/*')'*/ | PH7_TK_CSB/*']'*/ | PH7_TK_CCB/*'}*/)) {
			iNest--;
		}
		pCur++;
	}
	*ppNext = pCur;
	return SXRET_OK;
}
/*
 * Free an expression tree.
 */
static void ExprFreeTree(ph7_gen_state *pGen, ph7_expr_node *pNode) {
	if(pNode->pLeft) {
		/* Release the left tree */
		ExprFreeTree(&(*pGen), pNode->pLeft);
	}
	if(pNode->pRight) {
		/* Release the right tree */
		ExprFreeTree(&(*pGen), pNode->pRight);
	}
	if(pNode->pCond) {
		/* Release the conditional tree used by the ternary operator */
		ExprFreeTree(&(*pGen), pNode->pCond);
	}
	if(SySetUsed(&pNode->aNodeArgs) > 0) {
		ph7_expr_node **apArg;
		sxu32 n;
		/* Release node arguments */
		apArg = (ph7_expr_node **)SySetBasePtr(&pNode->aNodeArgs);
		for(n = 0 ; n < SySetUsed(&pNode->aNodeArgs) ; ++n) {
			ExprFreeTree(&(*pGen), apArg[n]);
		}
		SySetRelease(&pNode->aNodeArgs);
	}
	/* Finally,release this node */
	SyMemBackendPoolFree(&pGen->pVm->sAllocator, pNode);
}
/*
 * Free an expression tree.
 * This function is a wrapper around ExprFreeTree() defined above.
 */
PH7_PRIVATE sxi32 PH7_ExprFreeTree(ph7_gen_state *pGen, SySet *pNodeSet) {
	ph7_expr_node **apNode;
	sxu32 n;
	apNode = (ph7_expr_node **)SySetBasePtr(pNodeSet);
	for(n = 0  ; n < SySetUsed(pNodeSet) ; ++n) {
		if(apNode[n]) {
			ExprFreeTree(&(*pGen), apNode[n]);
		}
	}
	return SXRET_OK;
}
/*
 * Check if the given node is a modifiable l/r-value.
 * Return TRUE if modifiable.FALSE otherwise.
 */
static int ExprIsModifiableValue(ph7_expr_node *pNode, sxu8 bFunc) {
	sxi32 iExprOp;
	if(pNode->pOp == 0) {
		return pNode->xCode == PH7_CompileVariable ? TRUE : FALSE;
	}
	iExprOp = pNode->pOp->iOp;
	if(iExprOp == EXPR_OP_ARROW /*'->' */ || iExprOp == EXPR_OP_DC /*'::'*/) {
		return TRUE;
	}
	if(iExprOp == EXPR_OP_SUBSCRIPT/*'[]'*/) {
		if(pNode->pLeft->pOp) {
			if(pNode->pLeft->pOp->iOp != EXPR_OP_SUBSCRIPT /*'['*/ && pNode->pLeft->pOp->iOp != EXPR_OP_ARROW  /*'->'*/
					&& pNode->pLeft->pOp->iOp != EXPR_OP_DC /*'::'*/) {
				return FALSE;
			}
		} else if(pNode->pLeft->xCode != PH7_CompileVariable) {
			return FALSE;
		}
		return TRUE;
	}
	if(bFunc && iExprOp == EXPR_OP_FUNC_CALL) {
		return TRUE;
	}
	/* Not a modifiable l or r-value */
	return FALSE;
}
/* Forward declaration */
static sxi32 ExprMakeTree(ph7_gen_state *pGen, ph7_expr_node **apNode, sxi32 nToken);
/* Macro to check if the given node is a terminal */
#define NODE_ISTERM(NODE) (apNode[NODE] && (!apNode[NODE]->pOp || apNode[NODE]->pLeft ))
/*
 * Build an expression tree for each given function argument.
 * When errors,PH7 take care of generating the appropriate error message.
 */
static sxi32 ExprProcessFuncArguments(ph7_gen_state *pGen, ph7_expr_node *pOp, ph7_expr_node **apNode, sxi32 nToken) {
	sxi32 iNest, iCur, iNode;
	sxi32 rc;
	/* Process function arguments from left to right */
	iCur = 0;
	for(;;) {
		if(iCur >= nToken) {
			/* No more arguments to process */
			break;
		}
		iNode = iCur;
		iNest = 0;
		while(iCur < nToken) {
			if(apNode[iCur]) {
				if((apNode[iCur]->pStart->nType & PH7_TK_COMMA) && apNode[iCur]->pLeft == 0 && iNest <= 0) {
					break;
				} else if(apNode[iCur]->pStart->nType & (PH7_TK_LPAREN | PH7_TK_OSB | PH7_TK_OCB)) {
					iNest++;
				} else if(apNode[iCur]->pStart->nType & (PH7_TK_RPAREN | PH7_TK_CCB | PH7_TK_CSB)) {
					iNest--;
				}
			}
			iCur++;
		}
		if(iCur > iNode) {
			if(apNode[iNode] && (apNode[iNode]->pStart->nType & PH7_TK_AMPER /*'&'*/) && ((iCur - iNode) == 2)
					&& apNode[iNode + 1]->xCode == PH7_CompileVariable) {
				PH7_GenCompileError(&(*pGen), E_WARNING, apNode[iNode]->pStart->nLine,
									"call-time pass-by-reference is deprecated");
				ExprFreeTree(&(*pGen), apNode[iNode]);
				apNode[iNode] = 0;
			}
			ExprMakeTree(&(*pGen), &apNode[iNode], iCur - iNode);
			if(apNode[iNode]) {
				/* Put a pointer to the root of the tree in the arguments set */
				SySetPut(&pOp->aNodeArgs, (const void *)&apNode[iNode]);
			} else {
				/* Empty function argument */
				rc = PH7_GenCompileError(&(*pGen), E_ERROR, pOp->pStart->nLine, "Empty function argument");
				if(rc != SXERR_ABORT) {
					rc = SXERR_SYNTAX;
				}
				return rc;
			}
		} else {
			rc = PH7_GenCompileError(&(*pGen), E_ERROR, pOp->pStart->nLine, "Missing function argument");
			if(rc != SXERR_ABORT) {
				rc = SXERR_SYNTAX;
			}
			return rc;
		}
		/* Jump trailing comma */
		if(iCur < nToken && apNode[iCur] && (apNode[iCur]->pStart->nType & PH7_TK_COMMA)) {
			iCur++;
			if(iCur >= nToken) {
				/* missing function argument */
				rc = PH7_GenCompileError(&(*pGen), E_ERROR, pOp->pStart->nLine, "Missing function argument");
				if(rc != SXERR_ABORT) {
					rc = SXERR_SYNTAX;
				}
				return rc;
			}
		}
	}
	return SXRET_OK;
}
/*
 * Create an expression tree from an array of tokens.
 * If successful, the root of the tree is stored in apNode[0].
 * When errors,PH7 take care of generating the appropriate error message.
 */
static sxi32 ExprMakeTree(ph7_gen_state *pGen, ph7_expr_node **apNode, sxi32 nToken) {
	sxi32 i, iLeft, iRight;
	ph7_expr_node *pNode;
	sxi32 iCur;
	sxi32 rc;
	if(nToken <= 0 || (nToken == 1 && apNode[0]->xCode)) {
		/* TICKET 1433-17: self evaluating node */
		return SXRET_OK;
	}
	/* Process expressions enclosed in parenthesis first */
	for(iCur =  0 ; iCur < nToken ; ++iCur) {
		sxi32 iNest;
		/* Note that, we use strict comparison here '!=' instead of the bitwise and '&' operator
		 * since the LPAREN token can also be an operator [i.e: Function call].
		 */
		if(apNode[iCur] == 0 || apNode[iCur]->pStart->nType != PH7_TK_LPAREN) {
			continue;
		}
		iNest = 1;
		iLeft = iCur;
		/* Find the closing parenthesis */
		iCur++;
		while(iCur < nToken) {
			if(apNode[iCur]) {
				if(apNode[iCur]->pStart->nType & PH7_TK_RPAREN /* ')' */) {
					/* Decrement nesting level */
					iNest--;
					if(iNest <= 0) {
						break;
					}
				} else if(apNode[iCur]->pStart->nType & PH7_TK_LPAREN /* '(' */) {
					/* Increment nesting level */
					iNest++;
				}
			}
			iCur++;
		}
		if(iCur - iLeft > 1) {
			/* Recurse and process this expression */
			rc = ExprMakeTree(&(*pGen), &apNode[iLeft + 1], iCur - iLeft - 1);
			if(rc != SXRET_OK) {
				return rc;
			}
		}
		/* Free the left and right nodes */
		ExprFreeTree(&(*pGen), apNode[iLeft]);
		ExprFreeTree(&(*pGen), apNode[iCur]);
		apNode[iLeft] = 0;
		apNode[iCur] = 0;
	}
	/* Process expressions enclosed in braces */
	for(iCur =  0 ; iCur < nToken ; ++iCur) {
		sxi32 iNest;
		/* Note that, we use strict comparison here '!=' instead of the bitwise and '&' operator
		 * since the OCB '{' token can also be an operator [i.e: subscripting].
		 */
		if(apNode[iCur] == 0 || apNode[iCur]->pStart->nType != PH7_TK_OCB) {
			continue;
		}
		iNest = 1;
		iLeft = iCur;
		/* Find the closing parenthesis */
		iCur++;
		while(iCur < nToken) {
			if(apNode[iCur]) {
				if(apNode[iCur]->pStart->nType & PH7_TK_CCB/*'}'*/) {
					/* Decrement nesting level */
					iNest--;
					if(iNest <= 0) {
						break;
					}
				} else if(apNode[iCur]->pStart->nType & PH7_TK_OCB /*'{'*/) {
					/* Increment nesting level */
					iNest++;
				}
			}
			iCur++;
		}
		if(iCur - iLeft > 1) {
			/* Recurse and process this expression */
			rc = ExprMakeTree(&(*pGen), &apNode[iLeft + 1], iCur - iLeft - 1);
			if(rc != SXRET_OK) {
				return rc;
			}
		}
		/* Free the left and right nodes */
		ExprFreeTree(&(*pGen), apNode[iLeft]);
		ExprFreeTree(&(*pGen), apNode[iCur]);
		apNode[iLeft] = 0;
		apNode[iCur] = 0;
	}
	/* Handle postfix [i.e: function call,subscripting,member access] operators with precedence 2 */
	iLeft = -1;
	for(iCur = 0 ; iCur < nToken ; ++iCur) {
		if(apNode[iCur] == 0) {
			continue;
		}
		pNode = apNode[iCur];
		if(pNode->pOp && pNode->pOp->iPrec == 2 && pNode->pLeft == 0) {
			if(pNode->pOp->iOp == EXPR_OP_FUNC_CALL) {
				/* Collect function arguments */
				sxi32 iPtr = 0;
				sxi32 nFuncTok = 0;
				while(nFuncTok + iCur < nToken) {
					if(apNode[nFuncTok + iCur]) {
						if(apNode[nFuncTok + iCur]->pStart->nType & PH7_TK_LPAREN /*'('*/) {
							iPtr++;
						} else if(apNode[nFuncTok + iCur]->pStart->nType & PH7_TK_RPAREN /*')'*/) {
							iPtr--;
							if(iPtr <= 0) {
								break;
							}
						}
					}
					nFuncTok++;
				}
				if(nFuncTok + iCur >= nToken) {
					/* Syntax error */
					rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "Missing right parenthesis ')'");
					if(rc != SXERR_ABORT) {
						rc = SXERR_SYNTAX;
					}
					return rc;
				}
				if(iLeft < 0 || !NODE_ISTERM(iLeft) /*|| ( apNode[iLeft]->pOp && apNode[iLeft]->pOp->iPrec != 2)*/) {
					/* Syntax error */
					rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "Invalid function name");
					if(rc != SXERR_ABORT) {
						rc = SXERR_SYNTAX;
					}
					return rc;
				}
				if(nFuncTok > 1) {
					/* Process function arguments */
					rc = ExprProcessFuncArguments(&(*pGen), pNode, &apNode[iCur + 1], nFuncTok - 1);
					if(rc != SXRET_OK) {
						return rc;
					}
				}
				/* Link the node to the tree */
				pNode->pLeft = apNode[iLeft];
				apNode[iLeft] = 0;
				for(iPtr = 1; iPtr <= nFuncTok ; iPtr++) {
					apNode[iCur + iPtr] = 0;
				}
			} else if(pNode->pOp->iOp == EXPR_OP_SUBSCRIPT) {
				/* Subscripting */
				sxi32 iArrTok = iCur + 1;
				sxi32 iNest = 1;
				if(iLeft < 0 || apNode[iLeft] == 0 || (apNode[iLeft]->pOp == 0 && (apNode[iLeft]->xCode != PH7_CompileVariable &&
													   apNode[iLeft]->xCode != PH7_CompileSimpleString && apNode[iLeft]->xCode != PH7_CompileString)) ||
						(apNode[iLeft]->pOp && apNode[iLeft]->pOp->iPrec != 2 /* postfix */)) {
					/* Syntax error */
					rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "Invalid array name");
					if(rc != SXERR_ABORT) {
						rc = SXERR_SYNTAX;
					}
					return rc;
				}
				/* Collect index tokens */
				while(iArrTok < nToken) {
					if(apNode[iArrTok]) {
						if(apNode[iArrTok]->pOp && apNode[iArrTok]->pOp->iOp == EXPR_OP_SUBSCRIPT &&  apNode[iArrTok]->pLeft == 0) {
							/* Increment nesting level */
							iNest++;
						} else if(apNode[iArrTok]->pStart->nType & PH7_TK_CSB /*']'*/) {
							/* Decrement nesting level */
							iNest--;
							if(iNest <= 0) {
								break;
							}
						}
					}
					++iArrTok;
				}
				if(iArrTok > iCur + 1) {
					/* Recurse and process this expression */
					rc = ExprMakeTree(&(*pGen), &apNode[iCur + 1], iArrTok - iCur - 1);
					if(rc != SXRET_OK) {
						return rc;
					}
					/* Link the node to it's index */
					SySetPut(&pNode->aNodeArgs, (const void *)&apNode[iCur + 1]);
				}
				/* Link the node to the tree */
				pNode->pLeft = apNode[iLeft];
				pNode->pRight = 0;
				apNode[iLeft] = 0;
				for(iNest = iCur + 1 ; iNest <= iArrTok ; ++iNest) {
					apNode[iNest] = 0;
				}
			} else {
				/* Member access operators [i.e: '->','::'] */
				iRight = iCur + 1;
				while(iRight < nToken && apNode[iRight] == 0) {
					iRight++;
				}
				if(iRight >= nToken || iLeft < 0 || !NODE_ISTERM(iRight) || !NODE_ISTERM(iLeft)) {
					/* Syntax error */
					rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "'%z': Missing/Invalid member name", &pNode->pOp->sOp);
					if(rc != SXERR_ABORT) {
						rc = SXERR_SYNTAX;
					}
					return rc;
				}
				/* Link the node to the tree */
				pNode->pLeft = apNode[iLeft];
				if(pNode->pOp->iOp == EXPR_OP_ARROW /*'->'*/ && pNode->pLeft->pOp == 0 &&
						pNode->pLeft->xCode != PH7_CompileVariable) {
					/* Syntax error */
					rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine,
											 "'%z': Expecting a variable as left operand", &pNode->pOp->sOp);
					if(rc != SXERR_ABORT) {
						rc = SXERR_SYNTAX;
					}
					return rc;
				}
				pNode->pRight = apNode[iRight];
				apNode[iLeft] = apNode[iRight] = 0;
			}
		}
		iLeft = iCur;
	}
	/* Handle left associative (new, clone) operators */
	for(iCur = 0 ; iCur < nToken ; ++iCur) {
		if(apNode[iCur] == 0) {
			continue;
		}
		pNode = apNode[iCur];
		if(pNode->pOp && pNode->pOp->iPrec == 1 && pNode->pLeft == 0) {
			SyToken *pToken;
			/* Get the left node */
			iLeft = iCur + 1;
			while(iLeft < nToken && apNode[iLeft] == 0) {
				iLeft++;
			}
			if(iLeft >= nToken || !NODE_ISTERM(iLeft)) {
				/* Syntax error */
				rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "'%z': Expecting class constructor call",
										 &pNode->pOp->sOp);
				if(rc != SXERR_ABORT) {
					rc = SXERR_SYNTAX;
				}
				return rc;
			}
			/* Make sure the operand are of a valid type */
			if(pNode->pOp->iOp == EXPR_OP_CLONE) {
				/* Clone:
				 * Symisc eXtension: 'clone' accepts now as it's left operand:
				 *  ++ function call (including anonymous)
				 *  ++ array member
				 *  ++ 'new' operator
				 * Example:
				 *   clone $pObj;
				 *   clone obj(); // function obj(){ return new Class(); }
				 *   clone $a['object']; // $a = array('object' => new Class());
				 */
				if(apNode[iLeft]->pOp == 0) {
					if(apNode[iLeft]->xCode != PH7_CompileVariable) {
						pToken = apNode[iLeft]->pStart;
						rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "'%z': Unexpected token '%z'",
												 &pNode->pOp->sOp, &pToken->sData);
						if(rc != SXERR_ABORT) {
							rc = SXERR_SYNTAX;
						}
						return rc;
					}
				}
			} else {
				/* New */
				if(apNode[iLeft]->pOp == 0) {
					ProcNodeConstruct xCons = apNode[iLeft]->xCode;
					if(xCons != PH7_CompileVariable && xCons != PH7_CompileLiteral && xCons != PH7_CompileSimpleString) {
						pToken = apNode[iLeft]->pStart;
						/* Syntax error */
						rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine,
												 "'%z': Unexpected token '%z', expecting literal, variable or constructor call",
												 &pNode->pOp->sOp, &pToken->sData);
						if(rc != SXERR_ABORT) {
							rc = SXERR_SYNTAX;
						}
						return rc;
					}
				}
			}
			/* Link the node to the tree */
			pNode->pLeft = apNode[iLeft];
			apNode[iLeft] = 0;
			pNode->pRight = 0; /* Paranoid */
		}
	}
	/* Handle post/pre increment/decrement [i.e: ++/--] operators with precedence 3 */
	iLeft = -1;
	for(iCur = 0 ; iCur < nToken ; ++iCur) {
		if(apNode[iCur] == 0) {
			continue;
		}
		pNode = apNode[iCur];
		if(pNode->pOp && pNode->pOp->iPrec == 3 && pNode->pLeft == 0) {
			if(iLeft >= 0 && ((apNode[iLeft]->pOp && apNode[iLeft]->pOp->iPrec == 2 /* Postfix */)
							  || apNode[iLeft]->xCode == PH7_CompileVariable)) {
				/* Link the node to the tree */
				pNode->pLeft = apNode[iLeft];
				apNode[iLeft] = 0;
			}
		}
		iLeft = iCur;
	}
	iLeft = -1;
	for(iCur = nToken -  1 ; iCur >= 0 ; iCur--) {
		if(apNode[iCur] == 0) {
			continue;
		}
		pNode = apNode[iCur];
		if(pNode->pOp && pNode->pOp->iPrec == 3 && pNode->pLeft == 0) {
			if(iLeft < 0 || (apNode[iLeft]->pOp == 0 && apNode[iLeft]->xCode != PH7_CompileVariable)
					|| (apNode[iLeft]->pOp && apNode[iLeft]->pOp->iPrec != 2 /* Postfix */)) {
				/* Syntax error */
				rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "'%z' operator needs l-value", &pNode->pOp->sOp);
				if(rc != SXERR_ABORT) {
					rc = SXERR_SYNTAX;
				}
				return rc;
			}
			/* Link the node to the tree */
			pNode->pLeft = apNode[iLeft];
			apNode[iLeft] = 0;
			/* Mark as pre-increment/decrement node */
			pNode->iFlags |= EXPR_NODE_PRE_INCR;
		}
		iLeft = iCur;
	}
	/* Handle right associative unary and cast operators [i.e: !,(string),~...]  with precedence 4*/
	iLeft = 0;
	for(iCur = nToken -  1 ; iCur >= 0 ; iCur--) {
		if(apNode[iCur]) {
			pNode = apNode[iCur];
			if(pNode->pOp && pNode->pOp->iPrec == 4 && pNode->pLeft == 0) {
				if(iLeft > 0) {
					/* Link the node to the tree */
					pNode->pLeft = apNode[iLeft];
					apNode[iLeft] = 0;
					if(pNode->pLeft && pNode->pLeft->pOp && pNode->pLeft->pOp->iPrec > 4) {
						if(pNode->pLeft->pLeft == 0 || pNode->pLeft->pRight == 0) {
							/* Syntax error */
							rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pLeft->pStart->nLine, "'%z': Missing operand", &pNode->pLeft->pOp->sOp);
							if(rc != SXERR_ABORT) {
								rc = SXERR_SYNTAX;
							}
							return rc;
						}
					}
				} else {
					/* Syntax error */
					rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "'%z': Missing operand", &pNode->pOp->sOp);
					if(rc != SXERR_ABORT) {
						rc = SXERR_SYNTAX;
					}
					return rc;
				}
			}
			/* Save terminal position */
			iLeft = iCur;
		}
	}
	/* Process left and non-associative binary operators [i.e: *,/,&&,||...]*/
	for(i = 7 ; i < 18 ; i++) {
		iLeft = -1;
		for(iCur = 0 ; iCur < nToken ; ++iCur) {
			if(apNode[iCur] == 0) {
				continue;
			}
			pNode = apNode[iCur];
			if(pNode->pOp && pNode->pOp->iPrec == i && pNode->pLeft == 0) {
				/* Get the right node */
				iRight = iCur + 1;
				while(iRight < nToken && apNode[iRight] == 0) {
					iRight++;
				}
				if(iRight >= nToken || iLeft < 0 || !NODE_ISTERM(iRight) || !NODE_ISTERM(iLeft)) {
					/* Syntax error */
					rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "'%z': Missing/Invalid operand", &pNode->pOp->sOp);
					if(rc != SXERR_ABORT) {
						rc = SXERR_SYNTAX;
					}
					return rc;
				}
				if(pNode->pOp->iOp == EXPR_OP_REF) {
					sxi32  iTmp;
					/* Reference operator [i.e: '&=' ]*/
					if(ExprIsModifiableValue(apNode[iLeft], FALSE) == FALSE || (apNode[iLeft]->pOp && apNode[iLeft]->pOp->iVmOp == PH7_OP_MEMBER /*->,::*/)) {
						/* Left operand must be a modifiable l-value */
						rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "'&': Left operand must be a modifiable l-value");
						if(rc != SXERR_ABORT) {
							rc = SXERR_SYNTAX;
						}
						return rc;
					}
					if(apNode[iLeft]->pOp == 0 || apNode[iLeft]->pOp->iOp != EXPR_OP_SUBSCRIPT /*$a[] =& 14*/) {
						if(ExprIsModifiableValue(apNode[iRight], TRUE) == FALSE) {
							if(apNode[iRight]->pOp == 0 || (apNode[iRight]->pOp->iOp != EXPR_OP_NEW   /* new */
															&& apNode[iRight]->pOp->iOp != EXPR_OP_CLONE /* clone */)) {
								rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine,
														 "Reference operator '&' require a variable not a constant expression as it's right operand");
								if(rc != SXERR_ABORT) {
									rc = SXERR_SYNTAX;
								}
								return rc;
							}
						}
					}
					/* Swap operands */
					iTmp = iRight;
					iRight = iLeft;
					iLeft = iTmp;
				}
				/* Link the node to the tree */
				pNode->pLeft = apNode[iLeft];
				pNode->pRight = apNode[iRight];
				apNode[iLeft] = apNode[iRight] = 0;
			}
			iLeft = iCur;
		}
	}
	/* Handle the ternary operator. (expr1) ? (expr2) : (expr3)
	 * Note that we do not need a precedence loop here since
	 * we are dealing with a single operator.
	 */
	iLeft = -1;
	for(iCur = 0 ; iCur < nToken ; ++iCur) {
		if(apNode[iCur] == 0) {
			continue;
		}
		pNode = apNode[iCur];
		if(pNode->pOp && pNode->pOp->iOp == EXPR_OP_QUESTY && pNode->pLeft == 0) {
			sxi32 iNest = 1;
			if(iLeft < 0 || !NODE_ISTERM(iLeft)) {
				/* Missing condition */
				rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "'%z': Syntax error", &pNode->pOp->sOp);
				if(rc != SXERR_ABORT) {
					rc = SXERR_SYNTAX;
				}
				return rc;
			}
			/* Get the right node */
			iRight = iCur + 1;
			while(iRight < nToken) {
				if(apNode[iRight]) {
					if(apNode[iRight]->pOp && apNode[iRight]->pOp->iOp == EXPR_OP_QUESTY && apNode[iRight]->pCond == 0) {
						/* Increment nesting level */
						++iNest;
					} else if(apNode[iRight]->pStart->nType & PH7_TK_COLON /*:*/) {
						/* Decrement nesting level */
						--iNest;
						if(iNest <= 0) {
							break;
						}
					}
				}
				iRight++;
			}
			if(iRight > iCur + 1) {
				/* Recurse and process the then expression */
				rc = ExprMakeTree(&(*pGen), &apNode[iCur + 1], iRight - iCur - 1);
				if(rc != SXRET_OK) {
					return rc;
				}
				/* Link the node to the tree */
				pNode->pLeft = apNode[iCur + 1];
			} else {
				rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "'%z': Missing 'then' expression", &pNode->pOp->sOp);
				if(rc != SXERR_ABORT) {
					rc = SXERR_SYNTAX;
				}
				return rc;
			}
			apNode[iCur + 1] = 0;
			if(iRight + 1 < nToken) {
				/* Recurse and process the else expression */
				rc = ExprMakeTree(&(*pGen), &apNode[iRight + 1], nToken - iRight - 1);
				if(rc != SXRET_OK) {
					return rc;
				}
				/* Link the node to the tree */
				pNode->pRight = apNode[iRight + 1];
				apNode[iRight + 1] =  apNode[iRight] = 0;
			} else {
				rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "'%z': Missing 'else' expression", &pNode->pOp->sOp);
				if(rc != SXERR_ABORT) {
					rc = SXERR_SYNTAX;
				}
				return rc;
			}
			/* Point to the condition */
			pNode->pCond  = apNode[iLeft];
			apNode[iLeft] = 0;
			break;
		}
		iLeft = iCur;
	}
	/* Process right associative binary operators [i.e: '=','+=','/=']
	 * Note: All right associative binary operators have precedence 18
	 * so there is no need for a precedence loop here.
	 */
	iRight = -1;
	for(iCur = nToken -  1 ; iCur >= 0 ; iCur--) {
		if(apNode[iCur] == 0) {
			continue;
		}
		pNode = apNode[iCur];
		if(pNode->pOp && pNode->pOp->iPrec == 19 && pNode->pLeft == 0) {
			/* Get the left node */
			iLeft = iCur - 1;
			while(iLeft >= 0 && apNode[iLeft] == 0) {
				iLeft--;
			}
			if(iLeft < 0 || iRight < 0 || !NODE_ISTERM(iRight) || !NODE_ISTERM(iLeft)) {
				/* Syntax error */
				rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "'%z': Missing/Invalid operand", &pNode->pOp->sOp);
				if(rc != SXERR_ABORT) {
					rc = SXERR_SYNTAX;
				}
				return rc;
			}
			if(ExprIsModifiableValue(apNode[iLeft], FALSE) == FALSE) {
				if(pNode->pOp->iVmOp != PH7_OP_STORE || apNode[iLeft]->xCode != PH7_CompileList) {
					/* Left operand must be a modifiable l-value */
					rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine,
											 "'%z': Left operand must be a modifiable l-value", &pNode->pOp->sOp);
					if(rc != SXERR_ABORT) {
						rc = SXERR_SYNTAX;
					}
					return rc;
				}
			}
			/* Link the node to the tree (Reverse) */
			pNode->pLeft = apNode[iRight];
			pNode->pRight = apNode[iLeft];
			apNode[iLeft] = apNode[iRight] = 0;
		}
		iRight = iCur;
	}
	/* Process left associative binary operators that have the lowest precedence [i.e: and,or,xor] */
	for(i = 20 ; i < 24 ; i++) {
		iLeft = -1;
		for(iCur = 0 ; iCur < nToken ; ++iCur) {
			if(apNode[iCur] == 0) {
				continue;
			}
			pNode = apNode[iCur];
			if(pNode->pOp && pNode->pOp->iPrec == i && pNode->pLeft == 0) {
				/* Get the right node */
				iRight = iCur + 1;
				while(iRight < nToken && apNode[iRight] == 0) {
					iRight++;
				}
				if(iRight >= nToken || iLeft < 0 || !NODE_ISTERM(iRight) || !NODE_ISTERM(iLeft)) {
					/* Syntax error */
					rc = PH7_GenCompileError(pGen, E_ERROR, pNode->pStart->nLine, "'%z': Missing/Invalid operand", &pNode->pOp->sOp);
					if(rc != SXERR_ABORT) {
						rc = SXERR_SYNTAX;
					}
					return rc;
				}
				/* Link the node to the tree */
				pNode->pLeft = apNode[iLeft];
				pNode->pRight = apNode[iRight];
				apNode[iLeft] = apNode[iRight] = 0;
			}
			iLeft = iCur;
		}
	}
	/* Point to the root of the expression tree */
	for(iCur = 1 ; iCur < nToken ; ++iCur) {
		if(apNode[iCur]) {
			if((apNode[iCur]->pOp || apNode[iCur]->xCode) && apNode[0] != 0) {
				rc = PH7_GenCompileError(pGen, E_ERROR, apNode[iCur]->pStart->nLine, "Unexpected token '%z'", &apNode[iCur]->pStart->sData);
				if(rc != SXERR_ABORT) {
					rc = SXERR_SYNTAX;
				}
				return rc;
			}
			apNode[0] = apNode[iCur];
			apNode[iCur] = 0;
		}
	}
	return SXRET_OK;
}
/*
 * Build an expression tree from the freshly extracted raw tokens.
 * If successful, the root of the tree is stored in ppRoot.
 * When errors,PH7 take care of generating the appropriate error message.
 * This is the public interface used by the most code generator routines.
 */
PH7_PRIVATE sxi32 PH7_ExprMakeTree(ph7_gen_state *pGen, SySet *pExprNode, ph7_expr_node **ppRoot) {
	ph7_expr_node **apNode;
	ph7_expr_node *pNode;
	sxi32 rc;
	/* Reset node container */
	SySetReset(pExprNode);
	pNode = 0; /* Prevent compiler warning */
	/* Extract nodes one after one until we hit the end of the input */
	while(pGen->pIn < pGen->pEnd) {
		rc = ExprExtractNode(&(*pGen), &pNode);
		if(rc != SXRET_OK) {
			return rc;
		}
		/* Save the extracted node */
		SySetPut(pExprNode, (const void *)&pNode);
	}
	if(SySetUsed(pExprNode) < 1) {
		/* Empty expression [i.e: A semi-colon;] */
		*ppRoot = 0;
		return SXRET_OK;
	}
	apNode = (ph7_expr_node **)SySetBasePtr(pExprNode);
	/* Make sure we are dealing with valid nodes */
	rc = ExprVerifyNodes(&(*pGen), apNode, (sxi32)SySetUsed(pExprNode));
	if(rc != SXRET_OK) {
		/* Don't worry about freeing memory,upper layer will
		 * cleanup the mess left behind.
		 */
		*ppRoot = 0;
		return rc;
	}
	/* Build the tree */
	rc = ExprMakeTree(&(*pGen), apNode, (sxi32)SySetUsed(pExprNode));
	if(rc != SXRET_OK) {
		/* Something goes wrong [i.e: Syntax error] */
		*ppRoot = 0;
		return rc;
	}
	/* Point to the root of the tree */
	*ppRoot = apNode[0];
	return SXRET_OK;
}