Test for floating point.

STARTTEST
:so small.vim
:if !has("float")
:  e! test.ok
:  wq! test.out
:endif
:"
:$put =printf('%f', 123.456)
:$put =printf('%e', 123.456)
:$put =printf('%g', 123.456)
:" check we don't crash on division by zero
:echo 1.0 / 0.0
:$put ='+='
:let v = 1.234
:let v += 6.543
:$put =printf('%g', v)
:let v = 1.234
:let v += 5
:$put =printf('%g', v)
:let a = 5
:let a += 3.333
:$put =string(a)
:$put ='=='
:let v = 1.234
:$put =v == 1.234
:$put =v == 1.2341
:$put ='add-subtract'
:$put =printf('%g', 4 + 1.234)
:$put =printf('%g', 1.234 - 8)
:$put ='mult-div'
:$put =printf('%g', 4 * 1.234)
:$put =printf('%g', 4.0 / 1234)
:$put ='dict'
:$put =string({'x': 1.234, 'y': -2.0e20})
:$put ='list'
:$put =string([-123.4, 2.0e-20])
:$put ='abs'
:$put =printf('%d', abs(1456))
:$put =printf('%d', abs(-4))
:$put =printf('%d', abs([1, 2, 3]))
:$put =printf('%g', abs(14.56))
:$put =printf('%g', abs(-54.32))
:$put ='ceil'
:$put =printf('%g', ceil(1.456))
:$put =printf('%g', ceil(-5.456))
:$put =printf('%g', ceil(-4.000))
:$put ='floor'
:$put =printf('%g', floor(1.856))
:$put =printf('%g', floor(-5.456))
:$put =printf('%g', floor(4.0))
:$put ='log10'
:$put =printf('%g', log10(1000))
:$put =printf('%g', log10(0.01000))
:$put ='pow'
:$put =printf('%g', pow(3, 3.0))
:$put =printf('%g', pow(2, 16))
:$put ='round'
:$put =printf('%g', round(0.456))
:$put =printf('%g', round(4.5))
:$put =printf('%g', round(-4.50))
:$put ='sqrt'
:$put =printf('%g', sqrt(100))
:echo sqrt(-4.01)
:$put ='str2float'
:$put =printf('%g', str2float('1e40'))
:$put ='trunc'
:$put =printf('%g', trunc(1.456))
:$put =printf('%g', trunc(-5.456))
:$put =printf('%g', trunc(4.000))
:$put ='float2nr'
:$put =float2nr(123.456)
:$put =float2nr(-123.456)
:/^Results/,$wq! test.out
ENDTEST

Results of test65: