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More work on expressions

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git-svn-id: http://picoc.googlecode.com/svn/trunk@213 21eae674-98b7-11dd-bd71-f92a316d2d60
This commit is contained in:
zik.saleeba 2009-03-29 11:08:03 +00:00
parent 8baa2f71f7
commit 45a378231b
2 changed files with 17 additions and 5 deletions
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19
expression.c
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@ -422,6 +422,7 @@ int ExpressionParse(struct ParseState *Parser, struct Value **Result)
enum OperatorOrder
{
OrderNone,
OrderPrefix,
OrderInfix,
OrderPostfix
@ -447,6 +448,7 @@ struct OpPrecedence
static struct OpPrecedence OperatorPrecedence[] =
{
/* TokenNone, */ { 0, 0, 0 },
/* TokenComma, */ { 0, 0, 1 },
/* TokenAssign, */ { 0, 0, 2 }, /* TokenAddAssign, */ { 0, 0, 2 }, /* TokenSubtractAssign, */ { 0, 0, 2 },
/* TokenMultiplyAssign, */ { 0, 0, 2 }, /* TokenDivideAssign, */ { 0, 0, 2 }, /* TokenModulusAssign, */ { 0, 0, 2 },
@ -734,7 +736,7 @@ void ExpressionStackCollapse(struct ParseState *Parser, struct ExpressionStack *
struct ExpressionStack *TopStackNode = *StackTop;
struct ExpressionStack *TopOperatorNode;
while (TopStackNode != NULL && FoundPrecedence >= Precedence)
while (TopStackNode != NULL && TopStackNode->Next != NULL && FoundPrecedence >= Precedence)
{
/* find the top operator on the stack */
if (TopStackNode->Val != NULL)
@ -743,7 +745,7 @@ void ExpressionStackCollapse(struct ParseState *Parser, struct ExpressionStack *
TopOperatorNode = TopStackNode;
/* does it have a high enough precedence? */
if (FoundPrecedence >= Precedence)
if (FoundPrecedence >= Precedence && TopOperatorNode != NULL)
{
/* execute this operator */
switch (TopOperatorNode->Order)
@ -783,6 +785,9 @@ void ExpressionStackCollapse(struct ParseState *Parser, struct ExpressionStack *
/* do the infix operation */
ExpressionInfixOperator(Parser, StackTop, TopOperatorNode->Op, BottomValue, TopValue);
break;
case OrderNone:
break;
}
}
}
@ -803,7 +808,7 @@ void ExpressionStackPushOperator(struct ParseState *Parser, struct ExpressionSta
int ExpressionParse(struct ParseState *Parser, struct Value **Result)
{
struct Value *LexValue;
int PrefixState = FALSE;
int PrefixState = TRUE;
int Done = FALSE;
int BracketPrecedence = 0;
int LocalPrecedence;
@ -906,7 +911,13 @@ int ExpressionParse(struct ParseState *Parser, struct Value **Result)
/* scan and collapse the stack to precedence 0 */
ExpressionStackCollapse(Parser, &StackTop, 0);
//XXX - fix up the stack and return the result if we're in run mode
/* fix up the stack and return the result if we're in run mode */
if (StackTop != NULL)
{
/* all that should be left is a single value on the stack */
HeapPopStack((void *)StackTop - sizeof(struct ExpressionStack), sizeof(struct ExpressionStack));
}
return TRUE;
}

3
picoc.h
View file

@ -31,6 +31,7 @@ struct Table;
/* lexical tokens */
enum LexToken
{
TokenNone,
TokenComma,
TokenAssign, TokenAddAssign, TokenSubtractAssign, TokenMultiplyAssign, TokenDivideAssign, TokenModulusAssign,
TokenShiftLeftAssign, TokenShiftRightAssign, TokenArithmeticAndAssign, TokenArithmeticOrAssign, TokenArithmeticExorAssign,
@ -55,7 +56,7 @@ enum LexToken
TokenLongType, TokenSignedType, TokenShortType, TokenStructType, TokenUnionType, TokenUnsignedType, TokenTypedef,
TokenContinue, TokenDo, TokenElse, TokenFor, TokenIf, TokenWhile, TokenBreak, TokenSwitch, TokenCase, TokenDefault, TokenReturn,
TokenHashDefine, TokenHashInclude, TokenNew, TokenDelete,
TokenNone, TokenEOF, TokenEndOfLine, TokenEndOfFunction
TokenEOF, TokenEndOfLine, TokenEndOfFunction
};
/* used in dynamic memory allocation */