Line data    Source code

       1           0 : /*
       2             :         OOISNumberLiteral.m
       3             :         
       4             :         Copyright (C) 2008-2013 Jens Ayton
       5             :         
       6             :         Permission is hereby granted, free of charge, to any person obtaining a copy
       7             :         of this software and associated documentation files (the "Software"), to deal
       8             :         in the Software without restriction, including without limitation the rights
       9             :         to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
      10             :         copies of the Software, and to permit persons to whom the Software is
      11             :         furnished to do so, subject to the following conditions:
      12             :         
      13             :         The above copyright notice and this permission notice shall be included in all
      14             :         copies or substantial portions of the Software.
      15             :         
      16             :         THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
      17             :         IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
      18             :         FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
      19             :         AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
      20             :         LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
      21             :         OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
      22             :         SOFTWARE.
      23             : */
      24             : 
      25             : #import "OOIsNumberLiteral.h"
      26             : 
      27             : 
      28             : #if 0
      29             : #define FAIL(s)         do { NSLog(@"OOIsNumberLiteral failed for \"%@\": %@.", string, @s);  return NO; } while (0)
      30             : #else
      31           0 : #define FAIL(s)         do { return NO; } while (0)
      32             : #endif
      33             : 
      34             : 
      35           0 : BOOL OOIsNumberLiteral(NSString *string, BOOL allowSpaces)
      36             : {
      37             :         BOOL                                    leadingSpace = allowSpaces,
      38             :                                                         trailingSpace = NO,
      39             :                                                         allowSign = YES,
      40             :                                                         allowE = NO,
      41             :                                                         hadE = NO,
      42             :                                                         hadExp = NO,
      43             :                                                         allowDec = YES,
      44             :                                                         hadNumber = NO;
      45             :         NSUInteger                              i, count;
      46             :         
      47             :         if (string == nil)  return NO;
      48             :         
      49             :         count = [string length];
      50             :         for (i = 0; i != count; ++i)
      51             :         {
      52             :                 switch ([string characterAtIndex:i])
      53             :                 {
      54             :                         // <digit>
      55             :                         case '0':
      56             :                         case '1':
      57             :                         case '2':
      58             :                         case '3':
      59             :                         case '4':
      60             :                         case '5':
      61             :                         case '6':
      62             :                         case '7':
      63             :                         case '8':
      64             :                         case '9':
      65             :                                 leadingSpace = NO;
      66             :                                 if (trailingSpace)  FAIL("Digit after trailing whitespace");
      67             :                                 if (!hadE)  allowE = YES;
      68             :                                 else  hadExp = YES;
      69             :                                 allowSign = NO;
      70             :                                 hadNumber = YES;
      71             :                                 break;
      72             :                         
      73             :                         // <whitespaceChar>
      74             :                         case ' ':
      75             :                         case '\t':
      76             :                                 if (leadingSpace || trailingSpace)  break;
      77             :                                 if (hadNumber && allowSpaces)
      78             :                                 {
      79             :                                         trailingSpace = YES;
      80             :                                         allowSign = allowE = allowDec = NO;
      81             :                                         break;
      82             :                                 }
      83             :                                 FAIL("Space in unpermitted position");
      84             :                         
      85             :                         // <sign>
      86             :                         case '-':
      87             :                         case '+':
      88             :                                 leadingSpace = NO;
      89             :                                 if (allowSign)
      90             :                                 {
      91             :                                         allowSign = NO;
      92             :                                         break;
      93             :                                 }
      94             :                                 FAIL("Sign (+ or -) in unpermitted position");
      95             :                         
      96             :                         // <decimalPoint>
      97             :                         case '.':
      98             :                                 leadingSpace = NO;
      99             :                                 if (allowDec)
     100             :                                 {
     101             :                                         allowDec = NO;
     102             :                                         continue;
     103             :                                 }
     104             :                                 FAIL("Sign (+ or -) in unpermitted position");
     105             :                         
     106             :                         // <e>
     107             :                         case 'e':
     108             :                         case 'E':
     109             :                                 leadingSpace = NO;
     110             :                                 if (allowE)
     111             :                                 {
     112             :                                         allowE = NO;
     113             :                                         allowSign = YES;
     114             :                                         allowDec = NO;
     115             :                                         hadE = YES;
     116             :                                         continue;
     117             :                                 }
     118             :                                 FAIL("E in unpermitted position");
     119             :                         
     120             :                         default:
     121             :                                 FAIL ("Unpermitted character");
     122             :                 }
     123             :         }
     124             :         
     125             :         if (hadE && !hadExp)  FAIL("E with no exponent");
     126             :         if (!hadNumber)  FAIL("No digits in string");
     127             :         
     128             :         return YES;
     129             : }