complete_dict.jl

function CUSTOM_AUTOCOMPLETION_HOOK(txt,pos)
    m=match(r"(\w+)\[\"([^\"]*)$",txt[1:pos])
    if !isa(m,Nothing)
        #For String key
        if !isdefined(Main,parse(m.captures[1]))
            return UTF8String[], 0:-1, false
        end
        var=eval(parse(m.captures[1]))
        if !applicable(keys,var)
            return UTF8String[], 0:-1, false
        end
        ky=keys(var)
        if length(ky)>500
            return UTF8String[], 0:-1, false
        end
        ky=[filter(x->isa(x,String),ky)...]
        lst=convert(Vector{UTF8String},[filter(x->beginswith(x,m.captures[2]),ky)...])
        if !(length(txt)>=pos+1 && txt[pos+1]=='\"')
            if length(txt)>=pos+1 && txt[pos+1]==']'
                lst=map(x->x*"\"",lst)
            else
                lst=map(x->x*"\"]",lst)
            end
        end
        return lst, (pos-length(m.captures[2])+1):pos, true
    else
        #For symbol key
        m=match(r"(\w+)\[\:(\w*)$",txt[1:pos])
        if isa(m,Nothing) || !isdefined(Main,parse(m.captures[1]))
            return UTF8String[], 0:-1, false
        end
        var=eval(parse(m.captures[1]))
        if !applicable(keys,var)
            return UTF8String[], 0:-1, false
        end
        ky=keys(var)
        if length(ky)>500
            return UTF8String[], 0:-1, false
        end
        ky=map(string,[filter(x->isa(x,Symbol),ky)...])
        lst=convert(Vector{UTF8String},[filter(x->beginswith(x,m.captures[2]),ky)...])
        if !(length(txt)>=pos+1 && txt[pos+1]==']')
            lst=map(x->x*"]",lst)
        end
        return lst, (pos-length(m.captures[2])+1):pos, true
    end
end

REPLCompletions.diff

diff --git a/base/REPLCompletions.jl b/base/REPLCompletions.jl
index df8c965..d9a8a2c 100644
--- a/base/REPLCompletions.jl
+++ b/base/REPLCompletions.jl
@@ -183,6 +183,17 @@ function latex_completions(string, pos)
 end
 
 function completions(string, pos)
+    try
+        if isdefined(Main, :CUSTOM_AUTOCOMPLETION_HOOK)
+            t=Main.CUSTOM_AUTOCOMPLETION_HOOK(string, pos)
+            if t[3]
+                return t
+            end
+        end
+    catch err
+        println("Error in CUSTOM_AUTOCOMPLETION_HOOK:")
+        println(err)
+    end
     # First parse everything up to the current position
     partial = string[1:pos]
     inc_tag = Base.incomplete_tag(parse(partial , raise=false))