private static String removeLinebreaksFromComment(String token) {
if (TokenClassification.isLineComment(token)) {
token = "/*" + token.substring(2) + "*/";
}
StringBuilder sb = new StringBuilder(token);
// Section 5.1.2 hinges on whether a MultiLineComment contains a
// line-terminator char, so make sure it does not.
for (int i = sb.length(); --i >= 0; ) {
if (JsLexer.isJsLineSeparator(sb.charAt(i))) {
sb.setCharAt(i, ' ');
}
}
// Make sure that turning a line comment into a MultiLineComment didn't
// cause a */ in the line comment to become lexically significant.
for (int e = sb.length() - 3, i; (i = sb.lastIndexOf("*/", e)) >= 0; ) {
sb.setCharAt(i + 1, ' ');
}
return sb.toString();
}
void processToken(String text) {
TokenClassification tClass = TokenClassification.classify(text);
if (tClass == null) {
return;
}
switch (tClass) {
case LINEBREAK:
// Allow external code to force line-breaks.
// This allows us to create a composite-renderer that renders
// original source code next to translated source code.
emit("\n");
return;
case SPACE:
pendingSpace = true;
return;
case COMMENT:
if (mark != null && lastLine != mark.startLineNo()) {
newline();
lastLine = mark.startLineNo();
} else if ("/".equals(lastToken) || pendingSpace) {
space();
}
pendingSpace = false;
emit(text);
if (text.startsWith("//")) {
newline();
pendingSpace = false;
} else {
pendingSpace = true;
}
return;
default:
break;
}
boolean spaceBefore = pendingSpace;
pendingSpace = false;
boolean spaceAfter = false;
// Determine which pairs of tokens cannot be adjacent and put a space
// between them.
if (tClass == lastClass) {
// Adjacent punctuation, strings, and words require space.
// Numbers and words are both of type OTHER.
// This decision may be revisited in the following to prevent
// excessive space inside parentheses.
spaceBefore = !"(".equals(lastToken);
} else if (lastClass == TokenClassification.REGEX) {
if (tClass == TokenClassification.OTHER || "/".equals(text)) {
// Make sure words don't run into regex flags, and that / operator
// does not combine with end of regex to make a line comment.
spaceBefore = true;
}
} else if (tClass == TokenClassification.REGEX && "/".equals(lastToken)) {
// Allowing these two tokens to run together could introduce a line
// comment.
spaceBefore = true;
} else if (tClass == TokenClassification.OTHER
&& Character.isDigit(text.charAt(0))
&& ".".equals(lastToken)) {
// Following a dot operator with a number is illegal syntactically, but
// this renderer should not allow any lexical confusion.
spaceBefore = true;
}
if (tClass == TokenClassification.OTHER) {
if ("}".equals(lastToken)) {
spaceBefore = true;
}
if (isKeyword(text.toString())) {
// Put a space between if and other keywords and the parenthesis.
spaceAfter = true;
}
}
// If this token is an open bracket, we want to indent, but not before
// writing the token to avoid over-indenting the open bracket.
if (text.length() == 1) {
char ch0 = text.charAt(0);
switch (ch0) {
case '{':
if (lastClass == TokenClassification.PUNCTUATION) {
if (":".equals(lastToken)) { // See JSON test.
spaceBefore = true;
} else if (!(")".equals(lastToken) || "=".equals(lastToken))) {
// If starting a block following a parenthesized condition, or
// an object literal assigned.
spaceBefore = !("(".equals(lastToken) || "[".equals(lastToken));
}
}
spaceAfter = true;
break;
case '[':
if (")".equals(lastToken)) {
spaceBefore = false;
}
spaceAfter = true;
break;
case '(':
if (")".equals(lastToken)) { // Calling a parenthesized value.
spaceBefore = false;
}
break;
case '}':
spaceBefore = !"{".equals(lastToken);
spaceAfter = true;
break;
case ')':
spaceBefore = false;
spaceAfter = true;
break;
case ']':
spaceBefore = !"}".equals(lastToken);
spaceAfter = true;
break;
case ',':
spaceBefore = false;
spaceAfter = true;
break;
case ';':
spaceBefore = false;
spaceAfter = true;
break;
case ':':
spaceBefore = ":".equals(lastToken); // Since :: is a token in ES4
spaceAfter = true;
break;
case '=':
spaceBefore = true;
spaceAfter = true;
break;
case '.':
spaceBefore =
lastToken != null
&& (TokenClassification.isNumber(lastToken) || ".".equals(lastToken));
spaceAfter = false;
break;
}
}
// Write any whitespace before the token.
if (spaceBefore) {
space();
}
// Actually write the token.
emit(text);
pendingSpace = spaceAfter;
lastClass = tClass;
lastToken = text;
if (mark != null) {
lastLine = mark.startLineNo();
}
}
/** @throws NullPointerException if out raises an IOException and ioExceptionHandler is null. */
public final void noMoreTokens() {
JsTokenAdjacencyChecker adjChecker = new JsTokenAdjacencyChecker();
String lastToken = null;
boolean noOutputWritten = true;
List<String> outputTokens = splitTokens(pending);
pending.clear();
String pendingSpace = null;
for (int i = 0, nTokens = outputTokens.size(); i < nTokens; ++i) {
String token = outputTokens.get(i);
if (token.charAt(0) == '\n' || " ".equals(token)) {
pendingSpace = token;
continue;
}
if (TokenClassification.isComment(token)) {
// Make sure we don't get into a situation where we have to output
// a newline to end a line comment, but can't output a newline because
// it would break a restricted production.
// When we see a line comment, scan forward until the next non-comment
// token. If the canBreakBetween check fails, then remove any
// line-breaks by rewriting the comment.
// We have to rewrite multi-line block comments, since ES3 and ES5 say
// that a multi-line comment is replaced with a newline for the
// purposes of semicolon insertion.
//
// This is inconsistently implemented, but the rewriting works
// regardless of whether an implementation actually treats the
// comment as a newline for semicolon insertion.
String nextToken = null;
for (int j = i + 1; j < nTokens; ++j) {
switch (TokenClassification.classify(outputTokens.get(j))) {
case SPACE:
case LINEBREAK:
case COMMENT:
continue;
default:
break;
}
nextToken = outputTokens.get(j);
break;
}
if (!JsRenderUtil.canBreakBetween(lastToken, nextToken)) {
token = removeLinebreaksFromComment(token);
if (pendingSpace != null) {
pendingSpace = " ";
}
}
}
boolean needSpaceBefore = adjChecker.needSpaceBefore(token);
if (pendingSpace == null && needSpaceBefore) {
pendingSpace = " ";
}
if (pendingSpace != null) {
if (pendingSpace.charAt(0) == '\n') {
if (!JsRenderUtil.canBreakBetween(lastToken, token)) {
pendingSpace = " ";
} else if (noOutputWritten) {
pendingSpace = pendingSpace.substring(1);
}
}
out.append(pendingSpace);
pendingSpace = null;
}
out.append(token);
noOutputWritten = false;
if (!TokenClassification.isComment(token)) {
lastToken = token;
}
}
out.noMoreTokens();
}
