The R Project SVN R-packages

#import "../RegexKitLite.h"

#import "FileCompletion.h"

#import "../RController.h"

+ (NSArray*) retrieveSuggestionsForScopeRange:(NSRange)scopeRange inTextView:(NSTextView*)textView

{

	if (preventReentrance && insideR>0) {

		SLog(@"CodeCompletion.retrieveSuggestionForScope: returning nil completion to prevent R re-entrance [***]");

		return nil;

	}

	REngine *re = [REngine mainEngine];

	if (![re beginProtected]) {

		SLog(@"CodeCompletion.retrieveSuggestionForScope: returning nil completion because protected REngine entry failed [***]");

		return nil;

	}

	NSString *linebuffer = [[[textView textStorage] string] substringWithRange:scopeRange];

	SLog(@" - passed string for completion:\n%@", [linebuffer description]);

	if(!linebuffer || ![linebuffer length]) {

		[re endProtected];

		return nil;

	}

	// convert scope string to single line

	linebuffer = [linebuffer stringByReplacingOccurrencesOfRegex:@"[\n\r\t]+" withString:@" "];

	// first we need to find out whether we're in a text part or code part

	unichar c;

	int tl = [linebuffer length], tp=0, quotes=0, dquotes=0, lastQuote=-1;

	while (tp < tl) {

		c = CFStringGetCharacterAtIndex((CFStringRef)linebuffer, tp);

		if (c=='\\') 

			tp++; // skip the next char after a backslash (we don't have to worry about \023 and friends)

		else {

			if (dquotes==0 && c=='\'') {

				quotes^=1;

				if (quotes) lastQuote=tp;

			}

			if (quotes==0 && c=='"') {

				dquotes^=1;

				if (dquotes) lastQuote=tp;

			}

		}

		tp++;

	}

	// if we're inside any quotes, bail via file completion

	if (quotes+dquotes>0) {

		SLog(@" - cursor is inside quotes - call file completion");

		[re endProtected];

		return [FileCompletion completeAll:[linebuffer substringFromIndex:lastQuote+1] cutPrefix:0];

	}

	// use internal rcompgen to retrieve completion suggestions;

	// can be modified by the user via rc.setting s() and rc.options() resp.

	// escape ' since we pass it via @" '...' "

	linebuffer = [linebuffer stringByReplacingOccurrencesOfString:@"'" withString:@"\\'"];

	SLog(@" - rcompgen completion will be invoked with:\n%@", linebuffer);

	RSEXP *xx = [re evaluateString:[NSString stringWithFormat:@"rcompgen.completion('%@')", linebuffer]];

	[re endProtected];

	if(xx) {

		NSArray *ca = [xx array];

		// if only one suggestion was found set function hint in status bar

		if (ca && [ca count]==1) {

			NSString *foundItem = [ca objectAtIndex:0];

			// ignore all spaces, equal signs, and opened paranthesis at the end

			BOOL showIt = YES;

			int i = [foundItem length]-1;

			unichar c;

			while(i>0) {

				c = CFStringGetCharacterAtIndex((CFStringRef)foundItem, i);

				if(c == ' ' || c == '(') {

					i--;

				}

				else if (c == '=') {

					// if suggestion ends with a = do not show the hint, since

					// it's a parameter

					showIt = NO;

					break;

				}

				else

					break;

			}

			i++;

			foundItem = [foundItem substringToIndex:i];

			SLog(@" - show function hint '%@' with display %d", foundItem, showIt);

			if(showIt && [[(NSTextView*)[[NSApp keyWindow] firstResponder] delegate] respondsToSelector:@selector(hintForFunction:)])

				// (RController*) is only a dummy to avoid compiler warnings

				[(RController*)[(NSTextView*)[[NSApp keyWindow] firstResponder] delegate] hintForFunction:foundItem];

		}

		SLog(@" - found %d suggestions", [ca count]);

		[xx release];

		return (ca && [ca count]) ? ca : nil;

	}

	return nil;

}