Next: , Previous: Bitwise operations, Up: Arithmetic

5.5.4 Numeric comparison

Note that the words that compare for equality (= <> 0= 0<> d= d<> d0= d0<>) work for for both signed and unsigned numbers.

<       n1 n2 – f        core       “less-than”

<=       n1 n2 – f        gforth       “less-or-equal”

<>       n1 n2 – f        core-ext       “not-equals”

=       n1 n2 – f        core       “equals”

>       n1 n2 – f        core       “greater-than”

>=       n1 n2 – f        gforth       “greater-or-equal”

0<       n – f        core       “zero-less-than”

0<=       n – f        gforth       “zero-less-or-equal”

0<>       n – f        core-ext       “zero-not-equals”

0=       n – f        core       “zero-equals”

0>       n – f        core-ext       “zero-greater-than”

0>=       n – f        gforth       “zero-greater-or-equal”

u<       u1 u2 – f        core       “u-less-than”

u<=       u1 u2 – f        gforth       “u-less-or-equal”

u>       u1 u2 – f        core-ext       “u-greater-than”

u>=       u1 u2 – f        gforth       “u-greater-or-equal”

within       u1 u2 u3 – f        core-ext       “within”

u2=<u1<u3 or: u3=<u2 and u1 is not in [u3,u2). This works for unsigned and signed numbers (but not a mixture). Another way to think about this word is to consider the numbers as a circle (wrapping around from max-u to 0 for unsigned, and from max-n to min-n for signed numbers); now consider the range from u2 towards increasing numbers up to and excluding u3 (giving an empty range if u2=u3); if u1 is in this range, within returns true.

d<       d1 d2 – f        double       “d-less-than”

d<=       d1 d2 – f        gforth       “d-less-or-equal”

d<>       d1 d2 – f        gforth       “d-not-equals”

d=       d1 d2 – f        double       “d-equals”

d>       d1 d2 – f        gforth       “d-greater-than”

d>=       d1 d2 – f        gforth       “d-greater-or-equal”

d0<       d – f        double       “d-zero-less-than”

d0<=       d – f        gforth       “d-zero-less-or-equal”

d0<>       d – f        gforth       “d-zero-not-equals”

d0=       d – f        double       “d-zero-equals”

d0>       d – f        gforth       “d-zero-greater-than”

d0>=       d – f        gforth       “d-zero-greater-or-equal”

du<       ud1 ud2 – f        double-ext       “d-u-less-than”

du<=       ud1 ud2 – f        gforth       “d-u-less-or-equal”

du>       ud1 ud2 – f        gforth       “d-u-greater-than”

du>=       ud1 ud2 – f        gforth       “d-u-greater-or-equal”