add prepend!. closes JuliaLang#1854

jiahao · Mar 18, 2013 · 6ac3af4 · 6ac3af4
1 parent fa89045
commit 6ac3af4
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diff --git a/base/array.jl b/base/array.jl
@@ -666,6 +666,16 @@ function append!{T}(a::Array{T,1}, items::Array{T,1})
  return a
 end
 
+function prepend!{T}(a::Array{T,1}, items::Array{T,1})
+ if is(T,None)
+ error("[] cannot grow. Instead, initialize the array with \"T[]\".")
+ end
+ n = length(items)
+ ccall(:jl_array_grow_beg, Void, (Any, Uint), a, n)
+ a[1:n] = items
+ return a
+end
+
 function resize!(a::Vector, nl::Integer)
  l = length(a)
  if nl > l

diff --git a/base/exports.jl b/base/exports.jl
@@ -644,6 +644,7 @@ export
 
 # dequeues
  append!,
+ prepend!,
  resize!,
  insert!,
  shift!,