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- \l bigint.k
- / -- (not (n base 2)) ~ ((127 - n) base 2) for all base 127 digits n --
- `0:"-- use subtraction to not bits --"
- ~/(~2\!128;2\127-!128)
- / -- bigints use lists of digits --
- / Signed 7-bit numbers use the most significant bit for the signed bit
- / negation uses twos complement
- `0:"-- twos complement --"
- +2\*'(,59; \neg[,59])
- / -- since we're base 128, numbers which use the 7th bit need a leading zero --
- / to provide a signed bit.
- `0:"-- extra digit for signed bit --"
- ,/'+'2\'(0 69; \neg 0 69)
- / -- double negation is the identity --
- `0:"-- negation is own inverse --"
- neg neg[,69]
- neg neg[0 69]
- / -- for unsigned base 128 bigints, extra digit is not needed --
- `0:"-- unsigned addition --"
- add[,69;72]
- / -- signed addtion follows the convention above --
- `0:"-- signed addition --"
- adds[,69;,72]
- / -- Handling the signed bit is tricky --
- / test cases
- #T:,/,/:\:/2#,,',/1 neg'\T0:,/1(+|1(0 127@64>)\)\12 63 121
- / convert to integers
- c:{(-1 1s)*128/((neg;::)@s:64>*x)x}
- / test that digit-wise addition matches addition
- / covers (all?) the odd sign bit cases
- `0:"-- addtion test --"
- ~/(+/'c''T;c'adds.'T)
- / divisor times all positive digits base 128
- `0:"-- Render base 10 --"
- ms:128\'10*1_!128
- ($n)~ \,/$|*|(#*:){(!0;*|x),' \divmod[ms;*x]}/( \128\n:72932651;!0)
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