Default Sizes

If you don’t specify a size, the system assumes defaults based on the type:

• Integers: 8 bits (1 byte)
• Floats: 64 bits (8 bytes)
• Binaries/bitstrings: The entire binary

lfe> (binary 42)  ; Same as (binary (42 (size 8)))
#B(42)
lfe> (binary 1.5)  ; 64-bit float
#B(63 248 0 0 0 0 0 0)

That floating-point representation looks like line noise, doesn’t it? That’s IEEE 754 binary64 format, which is how computers have agreed to represent floating-point numbers ever since the IEEE standardization committee decided that “whatever hack your hardware happens to implement” was an insufficient specification for portable floating-point arithmetic. The details are fascinating if you’re into that sort of thing, and utterly terrifying if you’re trying to understand why 0.1 + 0.2 doesn’t exactly equal 0.3 in most programming languages.