The Weird and The Wonderful

s_mon wrote:

All errors are equal, but some errors are more equal than others...

String Test = "1Fa";
int Answer = int.Parse(Test, NumberStyles.HexNumber);

ans = c_val > '9' ? (10 + c_val - 'A') : c_val-'0';

riced wrote:

What's he/she got against the number 9?

case '0' :
   return Convert.ToInt32(Convert.ToString(pcChar));
   break;

default:
   { 
   throw new Exception(string.Format("\"{0}\" is an invalid value", pcChar));
   }

default:
   { 
   throw new Exception(string.Format("\"{0}\" is an invalid value", pcChar));
   return pcChar;
   break;
   }

Paulo Zemek wrote:

As this is the original pattern from 0 to 8 (9 is NOT a number, LOL)

# READ (char* bufer, int bufer_len)
# Reads a number from an ascii buffer and returns an actual number in eax
#
# PARAMETERS
# 	1. Address to the buffer
# 	2. The string's length
#
# Used registers:
# 	esi - contains all read characters
#	ecx - index inside the buffer
#	ebx - used in a conversion process char -> int
#	edx - address to the buffer
#	eax - the result
.globl read
.type read, @function
read:
	.equ DIGIT_0,'0'
	.equ DIGIT_9,'9'
	.equ CASE_A,'A'
	.equ CASE_F,'F'
	.equ CASE_a,'a'
	.equ CASE_f,'f'
	.equ ONE_DIGIT_MASK, 0x0000000F

	mov 8(%esp), %esi # save number of read chars

	mov $0, %ecx
	mov $0, %eax # there was the zero at the beginnig of the Universe
	cmp %ecx, %esi # empty string case
	je read_done

read_loop:
	mov $0, %ebx

	mov 4(%esp), %edx
	#mov (%edx), %edx	
	mov (%edx, %ecx, 1), %bl # take the next char
	cmp $DIGIT_9, %bl
	jle read_0to9

read_AtoF:
	cmp $CASE_a, %bl
	jge read_AtoF_lowercase
	sub $CASE_A, %bl # substitute'A'
	jmp read_AtoF_continue
read_AtoF_lowercase:
	sub $CASE_a, %bl # substitute 'A'
read_AtoF_continue:
	add $10, %bl # add 10 to get the correct value
	jmp read_char_done

read_0to9:
	cmp $DIGIT_0, %bl
	jl read_done
	sub $DIGIT_0, %bl # substitute '0'
	jmp read_char_done

read_char_done:
	# (bl is a lower part of ebx)
	add %ebx, %eax # ebx is a read-to-eat int
	
	inc %ecx # increment the index
	cmp %ecx, %esi # check if we're done
	je read_done
	
	shl $4, %eax # shift the number by one hex digit capacity.
	
	jmp read_loop
	
read_done:
	ret