Initial import of the ircii-pana-1.1-final source tree.

git-svn-id: svn://svn.code.sf.net/p/bitchx/code/tags/ircii-pana-1.1-final@1 13b04d17-f746-0410-82c6-800466cd88b0

dll/europa/cse476/grammar.cpp

@@ -0,0 +1,143 @@
+// Copyright (c) 1998-99, Ed Schlunder
+
+#include <fstream.h>
+#include <iostream.h>
+#include <string.h>
+#include "grammar.h"
+#include "gnode.h"
+
+Grammar::Grammar(char *fileName) {
+  char buffer[1000];
+  ifstream inFile;
+
+  // specify that this is currently an empty grammar rule list
+  rootPtr = currPtr = NULL;
+
+  // try to open the grammar rules file
+  inFile.open(fileName);
+  if(!inFile) {
+    cout << "Grammar rules file can not be opened." << endl;
+    return;
+  }
+
+  while(inFile) {
+    inFile.getline(buffer, 999);
+
+    // ignore blank lines
+    if(strlen(buffer) < 2) continue;
+    trim(buffer);
+    insert(buffer);
+  }
+}
+
+void Grammar::insert(char *text) {
+  List *ruleLine = new List;
+  genericNode *obj;
+  char *tmp;
+  int length, level, beg, end;
+
+  length = strlen(text);
+  end = -1;
+  while(end < length) {
+    beg = end + 1;
+    
+    // locate opening parenthesis
+    while(beg < length)
+      if(text[beg] == '(') break;
+      else beg++;
+
+    for(level = 0, end = beg + 1; end < length; end++) {
+      if((text[end] == ')') && (level == 0)) break;
+      
+      // make sure that items encased within () are kept intact
+      if(text[end] == '(') level++;
+      if(text[end] == ')') level--;
+    }
+
+    end++;
+    tmp = new char[end - beg + 1];
+    strncpy(tmp, text + beg, end - beg);
+    tmp[end - beg] = 0;
+
+    if(strlen(tmp) == 0)
+      break;
+
+    // make a genericNode out of this phrasal object and add it to the ruleLine
+    //    cout << '[' << tmp << ']' << endl;
+    obj = new genericNode(tmp);
+    ruleLine->InsertAfter(obj);
+  }
+
+  insert(ruleLine);
+}
+
+void Grammar::insert(List *ruleLine) {
+  grammarLine *tmp;
+
+  //  cout << "grammarInsert: " << *ruleLine << endl;
+  if(rootPtr == NULL) {
+    rootPtr = new grammarLine;
+    rootPtr->line = ruleLine;
+    rootPtr->nextPtr = NULL;
+  }
+  else {
+    // find end of list
+    tmp = rootPtr;
+    while(tmp->nextPtr != NULL)
+      tmp = tmp->nextPtr;
+
+    // tack a new rule on the end of the list
+    tmp->nextPtr = new grammarLine;
+    tmp = tmp->nextPtr;
+    tmp->line = ruleLine;
+    tmp->nextPtr = NULL;
+  }
+}
+
+Grammar::~Grammar() {
+  
+}
+
+List *Grammar::currLine(void) {
+  return currPtr->line;
+}
+
+void Grammar::goTop(void) {
+  currPtr = rootPtr;
+}
+
+bool Grammar::goNext(void) {
+  if(currPtr)
+    if(currPtr->nextPtr) {
+      currPtr = currPtr->nextPtr;
+      return true;
+    }
+  
+  return false;
+}
+
+List *Grammar::findMatch(genericNode *obj) {
+  searchObj = obj;
+  currPtr = rootPtr;
+
+  return findNext();
+}
+
+List *Grammar::findNext(void) {
+  List *assign, *currLine;
+
+  // go through each rule in the grammar and try to match it with the given obj
+  while(currPtr) {
+    currLine = currPtr->line;
+    currLine->GoTop();
+    currLine->GoNext();
+    assign = unify(*currLine->currItemNode(), *searchObj);
+
+    currPtr = currPtr->nextPtr;
+
+    if(assign)
+      return substitute(currLine, assign);
+  }
+
+  return NULL;
+}