*
* This was written as an ad-hoc parser to facilitate
* experimentation with the TIB spec. Once the spec is finalized it
- * should probably be rewritten using a parser-generator, if
- * possible (it is unclear whether or not the associated grammar is
- * context-free).
+ * should probably be rewritten.
*/
public class Tib implements Token.Stream<CharToken> {
public Tib(Reader r) throws IOException, Invalid { this(new BufferedReader(r)); }
public Tib(InputStream is) throws IOException, Invalid { this(new BufferedReader(new InputStreamReader(is))); }
public Tib(BufferedReader br) throws IOException, Invalid {
- cur = parse(br);
- System.out.println("\rparsing: \"" + cur.toString(0, -1) + "\"");
+ this.br = br;
+ istack.add(-1);
+ //cur = parse(br);
+ //System.out.println("\rparsing: \"" + cur.toString(0, -1) + "\"");
}
private Block cur;
- private String s = null;
+ private String s = "";
int pos = 0;
int spos = 0;
- int _row = 0;
+ int _row = 1;
int _col = 0;
- public CharToken next() throws IOException {
+ public Token.Location getLocation() { return new CharToken.CartesianLocation(_row, _col); }
+ private BufferedReader br;
+
+ boolean waiting = false;
+ char waitingChar = ' ';
+ boolean indenting = true;
+ int indentation = 0;
+ private ArrayList<Integer> istack = new ArrayList<Integer>();
+ public CharToken next(int numstates) throws IOException {
+ CharToken ret = nextc(numstates);
+ if (ret==CharToken.left) System.out.print("\033[31m{\033[0m");
+ else if (ret==CharToken.right) System.out.print("\033[31m}\033[0m");
+ else if (ret==null) return null;
+ else System.out.print(ret.c);
+ return ret;
+ }
+
+ CharToken waitingBrace = null;
+ public CharToken nextc(int numstates) throws IOException {
+ char c;
+ if (waitingBrace != null) {
+ CharToken ret = waitingBrace;
+ waitingBrace = null;
+ return ret;
+ }
+ if (waiting) {
+ waiting = false;
+ c = waitingChar;
+ } else {
+ int i = br.read();
+ if (i==-1) {
+ if (istack.size() > 1) {
+ istack.remove(istack.size()-1);
+ return CharToken.right;
+ }
+ return null;
+ }
+ c = (char)i;
+ }
+ if (c=='\n') { _row++; _col=0; }
+ else _col++;
+ if (indenting) {
+ if (c==' ') { indentation++; return done(c); }
+ if (c=='\n') { indentation = 0; if (blank) return nextc(numstates); blank = true; waiting = true; waitingChar='\n'; return new CharToken('\n'); }
+ int last = istack.size()==0 ? -1 : istack.get(istack.size()-1);
+ if (indentation==last) {
+ if (blank) {
+ indenting = false;
+ waitingChar = c;
+ waiting = true;
+ waitingBrace = CharToken.left;
+ return CharToken.right;
+ //return nextc(numstates);
+ }
+ blank = false;
+ indenting = false;
+ return done(c);
+ }
+ blank = false;
+ waitingChar = c;
+ waiting = true;
+ if (indentation > last) {
+ indenting = false;
+ istack.add(indentation);
+ System.out.print("\033[31m+"+indentation+"+\033[0m");
+ return CharToken.left;
+ } else /*if (indentation < last)*/ {
+ istack.remove(istack.size()-1);
+ System.out.print("\033[31m-"+last+"-\033[0m");
+ blank = true;
+ return CharToken.right;
+ }
+ } else {
+ blank = false;
+ if (c=='\n') { indenting=true; indentation = 0; }
+ return done(c);
+ }
+ }
+ public CharToken done(char c) {
+ switch(c) {
+ case '{': return CharToken.left;
+ case '}': return CharToken.right;
+ default: return new CharToken(c);
+ }
+ }
+ boolean blank = false;
+ /*
+ public CharToken next(int numstates) throws IOException {
if (cur==null) return null;
if (s != null) {
if (spos < s.length()) {
char c = s.charAt(spos++);
if (c=='\n') { _row++; _col = 0; }
else _col++;
- return new CharToken(c, _row, _col);
+ return new CharToken(c);
}
s = null;
}
if (pos >= cur.size()) {
pos = cur.iip+1;
+ _row = cur.endrow;
+ _col = cur.endcol;
cur = cur.parent;
if (cur==null) return null;
- return CharToken.right(_row, _col);
+ return CharToken.right;
}
Object o = cur.child(pos++);
if (o instanceof String) {
spos = 0;
s = (String)o;
- return next();
+ return next(numstates);
}
if (o instanceof Block) {
Block b = (Block)o;
if (((Block)o).isLiteral()) {
spos = 0;
s = ((Block.Literal)o).text();
- return next();
+ return next(numstates);
}
cur = (Block)o;
pos = 0;
- return CharToken.left(_row, _col);
+ return CharToken.left;
}
-
+ */
public static Block parse(BufferedReader br) throws Invalid, IOException {
int row=0, col=0;
try {
boolean blankLine = false;
Block top = new Block.Root();
for(String s = br.readLine(); s != null; s = br.readLine()) {
- col = 0;
+ row++;
+ col=0;
while (s.length() > 0 &&
s.charAt(0) == ' ' &&
(!(top instanceof Block.Literal) || col < top.col)) { col++; s = s.substring(1); }
while (col < top.col) {
if (s.startsWith("{}") && top instanceof Block.Literal && ((Block.Literal)top).braceCol == col) break;
blankLine = false;
+ top.endrow = row;
+ top.endcol = col;
top = top.closeIndent();
}
if (s.startsWith("{}")) {
}
while (s.length() > 0 && s.charAt(s.length()-1)==' ') { s = s.substring(0, s.length()-1); }
if (col > top.col) top = new Block.Indent(top, row, col);
- else if (blankLine) { top = top.closeIndent(); top = new Block.Indent(top, row, col); }
+ else if (blankLine) { top.endrow=row; top.endcol=col; top = top.closeIndent(); top = new Block.Indent(top, row, col); }
blankLine = false;
for(int i=0; i<s.length(); i++) {
top.add(s.charAt(i));
switch(s.charAt(i)) {
case '{': top = new Block.Brace(top, row, col); break;
- case '}': top = top.closeBrace(); break;
+ case '}': top.endrow=row; top.endcol=col; top = top.closeBrace(); break;
}
}
- top.add(' ');
+ top.add('\n');
top.finishWord();
}
// FIXME
}
}
- public static class Block /*implements Token*/ {
+ public static class Block {
Block parent;
public final int row;
public final int col;
+ public int endrow;
+ public int endcol;
public final int iip;
private final Vector children = new Vector();
private String pending = "";
- //public Location getLocation() { return /*new Location.Cartesian(row, col)*/null; }
public int size() { return children.size(); }
public Object child(int i) { return children.elementAt(i); }
public boolean isLiteral() { return false; }
// Testing //////////////////////////////////////////////////////////////////////////////
- public static void main(String[] s) throws Exception { System.out.println(parse(new BufferedReader(new InputStreamReader(System.in))).toString(-1)); }
+ public static void main(String[] s) throws Exception {
+ System.out.println(parse(new BufferedReader(new InputStreamReader(System.in))).toString(-1)); }
// Utilities //////////////////////////////////////////////////////////////////////////////
return ret.toString();
}
+ // Grammar //////////////////////////////////////////////////////////////////////////////
+
+ public static class Grammar extends MetaGrammar {
+ private int anon = 0;
+ private final Element ws = Repeat.maximal0(nonTerminal("w"));
+ public Grammar() { dropAll.add(ws); }
+ public Object walk(Tree<String> tree) {
+ String head = tree.head();
+ if (tree.numChildren()==0) return super.walk(tree);
+ if ("{".equals(head)) {
+ String s = "braced"+(anon++);
+ Union u = nonTerminal(s);
+ Union u2 = ((PreSequence)walk(tree, 0)).sparse(ws).buildUnion();
+ u2.add(Sequence.singleton(new Element[] { u }, 0, null, null));
+ return nonTerminal(s,
+ new PreSequence[][] {
+ new PreSequence[] {
+ new PreSequence(new Element[] { CharToken.leftBrace,
+ ws,
+ u2,
+ ws,
+ CharToken.rightBrace
+ })
+ }
+ },
+ false,
+ false);
+ }
+ return super.walk(tree);
+ }
+ }
+
}
projects / sbp.git / blobdiff