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/*

 *  R.app : a Cocoa front end to: "R A Computer Language for Statistical Data Analysis"

 *  

 *  R.app Copyright notes:

 *                     Copyright (C) 2004-5  The R Foundation

 *                     written by Stefano M. Iacus and Simon Urbanek

 *

 *                  

 *  R Copyright notes:

 *                     Copyright (C) 1995-1996   Robert Gentleman and Ross Ihaka

 *                     Copyright (C) 1998-2001   The R Development Core Team

 *                     Copyright (C) 2002-2004   The R Foundation

 *

 *  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.

 *

 *  A copy of the GNU General Public License is available via WWW at

 *  http://www.gnu.org/copyleft/gpl.html.  You can also obtain it by

 *  writing to the Free Software Foundation, Inc., 59 Temple Place,

 *  Suite 330, Boston, MA  02111-1307  USA.

 */

#import "CodeCompletion.h"

#import "../REngine/REngine.h"

#import "RGUI.h"

@implementation CodeCompletion

+ (NSString*) complete: (NSString*) part {

	if (preventReentrance && insideR>0) {

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

		return nil;

	}

    REngine *re = [REngine mainEngine];

	if (![re beginProtected]) {

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

		return nil;

	}

    // first get the length of the search path so we can go environment by environment

    RSEXP *x = [re evaluateString:@"length(search())"];

    int pos=1, maxpos;

    if (x==nil || ((maxpos = [x integer])==0)) { [re endProtected]; return nil; }

    // ok, we got the search path length; search in each environment and if something matches, get it, otherwise go to the next one

    while (pos<=maxpos) {

        // use ls to get the names of the objects in the specific environment

        NSString *ls=[NSString stringWithFormat:@"ls(pos=%d, all.names=TRUE, pattern=\"^%@.*\")", pos, part];

        RSEXP *x = [re evaluateString:ls];

        //NSLog(@"attepmting to find %@ via %@", part, ls);

        if (x==nil) {

			[re endProtected];

            return nil;

		}

        NSArray *a = [x array];

        if (a == nil) {

            [x release];

			[re endProtected];

            return nil;

        }

        { // the following code works also if pattern is not specified; with pattern present we could make it even easier, but currently we use it just to narrow the search (e.g. "." could still be matched by something else ...)

            int i=0, firstMatch=-1, matches=0;

            NSString *common=nil;

            while (i<[a count]) {

                NSString *sx = (NSString*) [a objectAtIndex:i];

                if ([sx hasPrefix: part]) {

                    if (matches==0) {

                        firstMatch=i;

                        common=[[NSString alloc] initWithString: sx];

                    } else {

                        NSString *cpref=[[NSString alloc] initWithString:[common commonPrefixWithString:sx options:0]];

                        [common release];

                        common=cpref;

                    }

                    matches++;

                }

                i++;

            }

            if (common!=nil) { // attempt to get class of the object - it will fail if that's just a partial object, but who cares..

                x = [re evaluateString:[NSString stringWithFormat:@"try(class(%@),silent=TRUE)",common]];

				[re endProtected];

                if (x!=nil && [x string]!=nil && [[x string] isEqualToString:@"function"])

                    return [[common autorelease] stringByAppendingString:@"("];

                else

                    return [common autorelease];

            }

        }

        pos++;

    }

	[re endProtected];

    return nil;

}

+ (NSArray*) completeAll: (NSString*) part cutPrefix: (int) prefix {

	if (preventReentrance && insideR>0) {

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

		return nil;

	}

    REngine *re = [REngine mainEngine];

	if (![re beginProtected]) {

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

		return nil;

	}

    // first get the length of the search path so we can go environment by environment

    RSEXP *x = [re evaluateString:@"length(search())"];

    int pos=1, maxpos, matches=0;

	NSMutableArray *ca = nil;

	NSString *common=nil;

    if (x==nil || ((maxpos = [x integer])==0)) { [re endProtected]; return nil; }

	ca = [[NSMutableArray alloc] initWithCapacity: 8];

    // ok, we got the search path length; search in each environment and if something matches, get it, otherwise go to the next one

    while (pos<=maxpos) {

        // use ls to get the names of the objects in the specific environment

        NSString *ls=[NSString stringWithFormat:@"ls(pos=%d, all.names=TRUE, pattern=\"^%@.*\")", pos, part];

        RSEXP *x = [re evaluateString:ls];

        //NSLog(@"attepmting to find %@ via %@", part, ls);

        if (x==nil) {

			[re endProtected];

            return nil;

		}

        NSArray *a = [x array];

        if (a == nil) {

            [x release];

			[re endProtected];

            return nil;

        }

        { // the following code works also if pattern is not specified; with pattern present we could make it even easier, but currently we use it just to narrow the search (e.g. "." could still be matched by something else ...)

            int i=0, firstMatch=-1;

            while (i<[a count]) {

                NSString *sx = (NSString*) [a objectAtIndex:i];

                if ([sx hasPrefix: part]) {

                    if (matches==0) {

                        firstMatch=i;

                        common=[[NSString alloc] initWithString: sx];

                    } else {

                        NSString *cpref=[[NSString alloc] initWithString:[common commonPrefixWithString:sx options:0]];

                        [common release];

                        common=cpref;

                    }

					if (prefix<[sx length]) {

						[ca addObject: [sx substringFromIndex:prefix]];

						matches++;

					}

                }

                i++;

            }

        }

        pos++;

    }

	if (common) { 

		if (matches==1) {

			// attempt to get class of the object - it will fail if that's just a partial object, but who cares..

			x = [re evaluateString:[NSString stringWithFormat:@"try(class(%@),silent=TRUE)",common]];

			[ca release];

			if (x!=nil && [x string]!=nil && [[x string] isEqualToString:@"function"]) {

				[re endProtected];

				return [NSArray arrayWithObject: [[[common autorelease] stringByAppendingString:@"("] substringFromIndex:prefix]];

			} else {

				[re endProtected];

				return [NSArray arrayWithObject: [[common autorelease] substringFromIndex:prefix]];

			}

		} else {

			[common release];

			[re endProtected];

			return ca;

		}

	}

	[re endProtected];

	[ca release];

    return nil;

}

@end