/* -*- mode: objc; coding: utf-8 -*- */ /* Étoilisp/Mulklisp, a Common Lisp subset for the Étoilé runtime. * Copyright (C) 2008 Matthias Andreas Benkard. * * 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 3 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. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #import "MLKReader.h" #import "MLKCharacter.h" #import "MLKReadtable.h" #import "MLKEndOfFileError.h" #import "MLKReaderError.h" #import "MLKDynamicContext.h" #import "MLKEnvironment.h" #import "MLKPackage.h" #import "MLKClosure.h" #import "MLKStream.h" #import "MLKFloat.h" #import "MLKInteger.h" #import "MLKRatio.h" #import #import #import #import @implementation MLKReader +(id) readFromStream:(MLKStream *)stream eofError:(BOOL)eofError eofValue:(id)eofValue recursive:(BOOL)recursive preserveWhitespace:(BOOL)preserveWhitespace { unichar ch; NSMutableString *token; MLKReadtable *readtable; BOOL escaped; readtable = [[MLKDynamicContext currentContext] valueForBinding:[[MLKPackage findPackage:@"COMMON-LISP"] intern:@"*READTABLE*"]]; start: if ([stream isEOF]) { if (eofError) [[[MLKEndOfFileError alloc] initWithStream:stream] raise]; else return eofValue; } ch = [stream readChar]; if ([readtable isWhitespaceCharacter:ch]) goto start; if ([readtable isMacroCharacter:ch]) { NSArray *returnValues; MLKClosure *macrofun = [readtable macroFunctionForCharacter:ch]; NSArray *args = [NSArray arrayWithObjects: stream, [MLKCharacter characterWithUnichar:ch], nil]; if ([args count] != 2) { args = [NSMutableArray arrayWithCapacity:2]; [((NSMutableArray*)args) addObject:stream]; [((NSMutableArray*)args) addObject:[MLKCharacter characterWithUnichar:ch]]; } returnValues = [macrofun applyToArray:args]; if ([returnValues count]) return [returnValues objectAtIndex:0]; else goto start; } escaped = NO; if ([readtable isSingleEscapeCharacter:ch]) { if ([stream isEOF]) [[[MLKEndOfFileError alloc] initWithStream:stream] raise]; token = [NSMutableString stringWithCapacity:8]; [token appendFormat:@"%C", [stream readChar]]; } if ([readtable isMultipleEscapeCharacter:ch]) { token = [NSMutableString stringWithCapacity:8]; escaped = YES; } if ([readtable isConstituentCharacter:ch]) { token = [NSMutableString stringWithCapacity:8]; [token appendFormat:@"%C", [stream readChar]]; } while (![stream isEOF]) { ch = [stream readChar]; if ([readtable isConstituentCharacter:ch] || [readtable isNonTerminatingMacroCharacter:ch] || (escaped && [readtable isWhitespaceCharacter:ch])) { if (escaped) [token appendFormat:@"%C", ch]; else [token appendFormat:@"%C", [readtable charWithReadtableCase:ch]]; } else if ([readtable isSingleEscapeCharacter:ch]) { if ([stream isEOF]) [[[MLKEndOfFileError alloc] initWithStream:stream] raise]; token = [NSMutableString stringWithCapacity:8]; [token appendFormat:@"%C", [stream readChar]]; } else if ([readtable isMultipleEscapeCharacter:ch]) escaped = !escaped; else if ([readtable isTerminatingMacroCharacter:ch]) { [stream unreadChar:ch]; break; } else if ([readtable isInvalid:ch]) { [[[MLKReaderError alloc] initWithStream:stream] raise]; } else if ([readtable isWhitespaceCharacter:ch]) { if (preserveWhitespace) [stream unreadChar:ch]; break; } } return [self interpretToken:token readtable:readtable]; } +(BOOL) isPotentialNumber:(NSString *)token readtable:(MLKReadtable *)readtable { // Check whether the token is a potential number. // // See CLHS 2.3.1.1. unsigned long i; unichar first; // 1. Does it consist solely of characters allowed in a potential // number? for (i = 0; i < [token length]; i++) { unichar ch = [token characterAtIndex:i]; if (!([readtable isDigit:ch] || [readtable isSign:ch] || [readtable isRatioMarker:ch] || [readtable isDecimalPoint:ch] || ch == '^' || ch == '_' || ([readtable isNumberMarker:ch] // Adjacent number markers aren't to be considered number // markers at all. && (i == 0 || ![readtable isNumberMarker:[token characterAtIndex:(i-1)]])))) return NO; } // 2. Does the token contain a digit? for (i = 0; i < [token length]; i++) { unichar ch = [token characterAtIndex:i]; if ([readtable isDigit:ch]) goto digitFound; } return NO; digitFound: // 3. Is the first character okay? first = [token characterAtIndex:0]; if (!([readtable isDigit:first] || [readtable isSign:first] || [readtable isDecimalPoint:first] || first == '^' || first == '_')) return NO; // 4. Does the token not end with a sign? if ([readtable isSign:[token characterAtIndex:([token length]-1)]]) return NO; return YES; } +(id) interpretToken:(NSString *)token readtable:(MLKReadtable *)readtable { if ([self isPotentialNumber:token readtable:readtable]) { unsigned long i, firstNum, secondNum, exponent, exponentMarkerPos; unichar sign, exponentSign; unichar firstSeparator, exponentMarker; BOOL negative; MLKInteger *base; base = [[MLKDynamicContext currentContext] valueForBinding:[[MLKPackage findPackage:@"COMMON-LISP"] intern:@"*READ-BASE*"]]; // Read the sign (if present). if ([readtable isSign:[token characterAtIndex:0]]) { sign = [token characterAtIndex:0]; i = 1; firstNum = 1; } else { i = 0; firstNum = 0; } negative = (firstNum > 0 && sign == '-'); while ((i < [token length]) && [readtable isDecimalDigit:[token characterAtIndex:i]]) i++; if (i == [token length]) { return [MLKInteger integerWithString: [token substringWithRange: NSMakeRange (firstNum, [token length] - firstNum)] negative:negative base:10]; } firstSeparator = [token characterAtIndex:i]; if (!([readtable isDecimalPoint:firstSeparator] || [readtable isExponentMarker:[token characterAtIndex:i]])) goto digits; i++; secondNum = i; if (i == [token length] && [readtable isDecimalPoint:firstSeparator]) { return [MLKInteger integerWithString: [token substringWithRange: NSMakeRange (firstNum, [token length] - firstNum - 1)] negative:negative base:10]; } else { // We're dealing with a floating point number. Bah. I hate // floating point numbers. if ([readtable isExponentMarker:firstSeparator]) { exponentMarkerPos = i; if ([readtable isSign:[token characterAtIndex:i]]) { exponentSign = [token characterAtIndex:i]; i++; } else exponentSign = '+'; exponent = i; while ((i < [token length]) && [readtable isDecimalDigit:[token characterAtIndex:i]]) i++; return [MLKFloat floatWithExponentMarker:firstSeparator integerPart:[token substringWithRange:NSMakeRange(firstNum, exponentMarkerPos - firstNum - 1)] negative:negative fractionalPart:@"" exponent:[token substringFromIndex:exponent] exponentNegative:(exponentSign == '-')]; } else { while ((i < [token length]) && [readtable isDecimalDigit:[token characterAtIndex:i]]) i++; if (i == [token length]) { return [MLKFloat floatWithExponentMarker:firstSeparator integerPart:[token substringWithRange:NSMakeRange (firstNum, secondNum - firstNum - 1)] negative:negative fractionalPart:[token substringFromIndex:secondNum] exponent:@"" exponentNegative:NO]; } // Assume token[i] is an exponent marker. exponentMarkerPos = i; exponentMarker = [token characterAtIndex:i]; i++; if ([readtable isSign:[token characterAtIndex:i]]) { exponentSign = [token characterAtIndex:i]; i++; } else exponentSign = '+'; exponent = i; while ((i < [token length]) && [readtable isDecimalDigit:[token characterAtIndex:i]]) i++; return [MLKFloat floatWithExponentMarker:exponentMarker integerPart:[token substringWithRange:NSMakeRange (firstNum, secondNum - firstNum - 1)] negative:negative fractionalPart:[token substringWithRange:NSMakeRange (secondNum, exponentMarkerPos - secondNum)] exponent:[token substringFromIndex:exponent] exponentNegative:(exponentSign == '-')]; } } digits: i = firstNum; while ((i < [token length]) && [readtable isDigit:[token characterAtIndex:0]]) i++; if (i == [token length]) { return [MLKInteger integerWithString: [token substringWithRange: NSMakeRange (firstNum, [token length] - firstNum)] negative:negative base:[base intValue]]; } // Assume token[i] is a slash. i++; secondNum = i; return [MLKRatio ratioWithNumeratorString: [token substringWithRange: NSMakeRange (firstNum, secondNum - firstNum - 1)] denominatorString:[token substringFromIndex:secondNum] negative:negative base:[base intValue]]; } else { unsigned long i, packageMarker; MLKPackage *package; NSString *symbolName; MLKSymbol *symbol; // Look for the package marker. packageMarker = -1; for (i = 0; i < [token length]; i++) { if ([readtable isPackageMarker:[token characterAtIndex:i]]) { packageMarker = i; break; } } // Extract the package and symbol name. if (packageMarker == -1) { package = [[MLKDynamicContext currentContext] valueForBinding:[[MLKPackage findPackage:@"COMMON-LISP"] intern:@"*PACKAGE*"]]; symbolName = token; } else if (packageMarker == 0) { package = [MLKPackage findPackage:@"KEYWORD"]; symbolName = [token substringFromIndex:1]; } else { package = [MLKPackage findPackage:[token substringToIndex:packageMarker]]; if ([readtable isPackageMarker:[token characterAtIndex:(i+1)]]) symbolName = [token substringFromIndex:(packageMarker+2)]; else { // A single package marker means we have to check whether // the symbol is external in the package. symbolName = [token substringFromIndex:(packageMarker+1)]; if (![[package exportedSymbols] containsObject:[package intern:token]]) [[[MLKReaderError alloc] init] raise]; } } symbol = [package intern:symbolName]; if (packageMarker == 0) { // Make keyword symbols self-evaluate. [[MLKDynamicContext currentContext] setValue:symbol forBinding:symbol]; } return symbol; } } @end