Subset df on string condition

I want to subset df on an unknown condition (say, randomly defined as in the example below):

df <- data.frame(a=1:10, b = 10:1)
condition <- paste0(sample(letters[1:2],1), sample(c("<",">"),1), sample(1:10,1))

I can do this with eval, which, vox populi, is suboptimal:

subset(df, eval(parse(text=condition)))

Is there an alternative to eval(parse)?