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Diffstat (limited to 'microbe/expression.h')
| -rw-r--r-- | microbe/expression.h | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/microbe/expression.h b/microbe/expression.h new file mode 100644 index 0000000..9607f16 --- /dev/null +++ b/microbe/expression.h @@ -0,0 +1,126 @@ +/*************************************************************************** + * Copyright (C) 2004-2005 by Daniel Clarke * + * [email protected] * + * * + * This program is free software; you can redistribute it and/or modify * + * it under the terms of the GNU General Public License as published by * + * the Free Software Foundation; either version 2 of the License, or * + * (at your option) any later version. * + * * + * This program is distributed in the hope that it will be useful, * + * but WITHOUT ANY WARRANTY; without even the implied warranty of * + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * + * GNU General Public License for more details. * + * * + * You should have received a copy of the GNU General Public License * + * along with this program; if not, write to the * + * Free Software Foundation, Inc., * + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. * + ***************************************************************************/ + +#ifndef EXPRESSION_H +#define EXPRESSION_H + +#include "microbe.h" + +#include <qstring.h> + +class PIC14; +class BTreeNode; +class Microbe; + +/** +@author Daniel Clarke +@author David Saxton +*/ +class Expression +{ + public: + enum Operation + { + noop, + addition, + subtraction, + multiplication, + division, + exponent, + equals, + notequals, + pin,//(returns the truth value obtatined by testing the pin) + notpin, //(the result of doing the pin op NOTted).] + read_keypad, //read value from keypad + function, + bwand, + bwor, + bwxor, + bwnot, + divbyzero, // used to make handling this situation easier + gt, + lt, + ge, + le + }; + + Expression(PIC14 *pic, Microbe *master, SourceLine sourceLine, bool supressNumberTooBig ); + ~Expression(); + + /** + * Generates the code needed to evaluate an expression. Firstly, a tree + * is generated from the expression string; then that tree is traversed + * to generate the assembly. + */ + void compileExpression( const QString & expression); + void compileConditional( const QString & expression, Code * ifCode, Code * elseCode ); + /** + * Returns a *number* rather than evaluating code, and sets isConstant to true + * if it the expression evaluated to a constant. + */ + QString processConstant( const QString & expr, bool * isConsant ); + + private: + PIC14 *m_pic; + Microbe *mb; + + /** Turns the operations encoded in the given tree into assembly code */ + void traverseTree( BTreeNode *root, bool conditionalRoot = false ); + + bool isUnaryOp(Operation op); + + void expressionValue( QString expression, BTreeBase *tree, BTreeNode *node ); + void doOp( Operation op, BTreeNode *left, BTreeNode *right ); + void doUnaryOp( Operation op, BTreeNode *node ); + /** + * Parses an expression, and generates a tree structure from it. + */ + void buildTree( const QString & expression, BTreeBase *tree, BTreeNode *node, int level ); + + static int findSkipBrackets( const QString & expr, char ch, int startPos = 0); + static int findSkipBrackets( const QString & expr, QString phrase, int startPos = 0); + + QString stripBrackets( QString expression ); + + void mistake( Microbe::MistakeType type, const QString & context = 0 ); + + SourceLine m_sourceLine; + + Code * m_ifCode; + Code * m_elseCode; + + /** + *Returns expression type + * 0 = directly usable number (literal) + * 1 = variable + * 2 = expression that needs evaluating + * (maybe not, see enum). + */ + ExprType expressionType( const QString & expression ); + static bool isLiteral( const QString &text ); + /** + * Normally, only allow numbers upto 255; but for some uses where the + * number is not going to be placed in a PIC register (such as when + * delaying), we can ignore numbers being too big. + */ + bool m_bSupressNumberTooBig; +}; + +#endif |