working prototype, written together with Charris

1 files changed, 112 insertions, 0 deletions

diff --git a/binaryLib.lua b/binaryLib.lua
new file mode 100644
index 0000000..cf8a167
--- /dev/null
+++ b/binaryLib.lua
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+ --[[
+Eugeniy Mikhailov
+1 June 2021
+ ]]
+------------ BITS TO DECIMAL ------------ 
+function toNum(bits)
+	local n = 0; local m = 1 -- m represents power of 2
+	for i = 1, #bits do -- '#' indicates number of bits in variable
+	  n = n + bits[i]*m
+	  m = m*2
+    end
+	return n
+end
+
+
+------------ DECIMAL TO BIT ------------ 
+-- ****NOTE: Suitable only for positive integer inputs****
+-- continue to divide by two until quotient is zero
+function toBits(num)    
+    local t = {}
+    while num > 0 do
+        remainder = num % 2 -- Basics of binary. If num is divisible by two, 0 in table. If not, 1 in table
+        table.insert(t, remainder)-- defaults to #t+1 key
+        num = (num - remainder)/2
+        --num = math.floor((num - remainder)/2) -- carry out calculation
+            -- note math.floor used here to eliminate floating values
+        --we subtract the number with the binary bit found, then divide by two to find the next bit
+    end
+    return t
+end
+
+------------ BINARY SEPARATION TO STRING ------------ 
+function bin2string(bTable, separator)
+    if  nil == separator then separator="" end
+    local str=""
+    for i=#bTable,1,-1 do
+        if (i % 8) == 0 then str=str..separator end -- space between every 8 bits
+        if bTable[i] == 0 -- to take care of floats
+        then
+            str=str.."0"
+        else 
+            str=str.."1" -- assumes only nonzeros are ones
+                -- if nonzeros/ones involved, will also be counted as ones here
+        end
+    end
+    return str
+end
+
+------------ TESTS FOR bin2string------------ 
+if "11111110" ~= bin2string(toBits(254))
+then
+    print("Error in bits conversion")
+end
+if 2376 ~= toNum(toBits(2376))
+then
+    print("Error in bits conversion")
+end
+
+------------ SLICE STRING ------------
+function bitSlice(bTable, low, high)
+    -- make sure that 1 <= low <= high
+    local slice={}
+    local cnt=1 --counter
+    for i=low,high
+    do
+        slice[cnt] = (bTable[i])
+        cnt = cnt+1
+    end
+    return slice
+end
+
+------------ TESTS FOR bitSlice ------------ 
+if "345" ~= table.concat(bitSlice({1,2,3,4,5,6,7,8}, 3,5))
+then
+    print("Error bitSlice is compromised")
+end
+
+------------ COPY TABLE ------------
+-- issue with index naming in future table. 
+function copyTableArray(src)
+    local dst={}
+    for i=1,#src do
+        dst[i] = (src[i])
+    end
+    return dst
+end
+
+------------ COMBINE SLICES ------------
+function tableReplace(bTable1, bTable2, low, high) -- low=first index, high=last index
+    local dest = copyTableArray(bTable1)
+    local cnt=1
+    for i=low,high do
+        dest[i]=(bTable2[cnt])
+        cnt = cnt + 1
+    end
+    return dest -- destination
+end
+
+------------ PAD ZEROS INTO EMPTY INDICES ------------
+function pad2NumBitsInPlace(bTable, num)
+    for i= #bTable+1, num do
+        bTable[i]=0
+    end
+    return bTable
+end
+
+------------ TEST PAD ZEROS ------------
+if "00010111" ~= bin2string(pad2NumBitsInPlace({1,1,1,0,1},8))
+then
+    print("Error in pad2NumBitsInPlace")
+end
+