testing a character

import std/strutils     # is...() functions


echo isDigit('9')       # true
# This checks 0-9 ASCII characters only.

echo isLowerAscii('m')       # true
echo isLowerAscii('G')       # false
# This checks ASCII characters only. Use `unicode` module for UTF-8 support.

echo isUpperAscii('m')       # false
echo isUpperAscii('G')       # true
# This checks ASCII characters only. Use `unicode` module for UTF-8 support.

echo isAlphaAscii('x')        # true
echo isAlphaAscii('.')        # false
# Is the char in the English alphabet? Can be lowercase or uppercase.
# This checks a-z, A-Z ASCII characters only.

echo isAlphaNumeric('h')      # true
echo isAlphaNumeric('H')      # true
echo isAlphaNumeric('5')      # true
# This checks a-z, A-Z, 0-9 ASCII characters only.

# func isEmptyOrWhitespace(s: string): bool {.....}
echo isEmptyOrWhitespace("")                # true
echo isEmptyOrWhitespace("  \t   \n   ")    # true
echo isEmptyOrWhitespace("  \t x  \n   ")   # false

echo isSpaceAscii(' ')      # true
echo isSpaceAscii('\t')     # true
echo isSpaceAscii('\n')     # true
# Is the char a whitespace character?