June 2018 Update

Task/Variable-length-quantity/00DESCRIPTION

@@ -1,6 +1,9 @@
 Implement some operations on [[wp:Variable-length quantity|variable-length quantities]], at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and ''vice versa''. Any variants are acceptable.
 
-'''Task :''' With above operations,
+
+;Task:
+With above operations,
 *convert these two numbers 0x200000 (2097152 in decimal) and 0x1fffff (2097151 in decimal) into sequences of octets (an eight-bit byte);
 *display these sequences of octets;
 *convert these sequences of octets back to numbers, and check that they are equal to original numbers.
+<br><br>

Task/Variable-length-quantity/Julia/variable-length-quantity.julia

@@ -1,34 +1,31 @@
-type VLQ
-    q::Array{Uint8,1}
+mutable struct VLQ
+    quant::Vector{UInt8}
 end
 
-function VLQ{T<:Integer}(n::T)
-    q = uint8(digits(n, 128))
-    for i in 2:length(q)
-        q[i] |= 0x80
-    end
-    VLQ(reverse(q))
+function VLQ(n::T) where T <: Integer
+    quant = UInt8.(digits(n, 128))
+    @inbounds for i in 2:length(quant) quant[i] |= 0x80 end
+    VLQ(reverse(quant))
 end
 
-function Base.uint(vlq::VLQ)
-    q = reverse(vlq.q)
-    n = shift!(q)
-    p = one(Uint64)
-    for i in q
+import Base.UInt64
+function Base.UInt64(vlq::VLQ)
+    quant = reverse(vlq.quant)
+    n = shift!(quant)
+    p = one(UInt64)
+    for i in quant
         p *= 0x80
-        n += p*(i&0x7f)
+        n += p * ( i & 0x7f)
     end
     return n
 end
 
-test = [0x00200000, 0x001fffff, 0x00000000, 0x0000007f,
-        0x00000080, 0x00002000, 0x00003fff, 0x00004000,
-        0x08000000, 0x0fffffff]
+const test = [0x00200000, 0x001fffff, 0x00000000, 0x0000007f,
+              0x00000080, 0x00002000, 0x00003fff, 0x00004000,
+              0x08000000, 0x0fffffff]
 
 for i in test
-    q = VLQ(i)
-    j = uint(q)
-    print(@sprintf "    0x%x => " i)
-    print(@sprintf "[%s]" join(["0x"*hex(r, 2) for r in q.q], ", "))
-    println(@sprintf " => 0x%x" j)
+    vlq = VLQ(i)
+    j = UInt(vlq)
+    @printf "0x%-8x => [%-25s] => 0x%x\n" i join(("0x" * hex(r, 2) for r in vlq.quant), ", ") j
 end