luaish: tab-completion of command history

luaish/lua.lua

@@ -28,7 +28,7 @@ else
     LUA_COPYRIGHT = "Copyright (C) 1994-2011 Lua.org, PUC-Rio"
     eof_ender = '<eof>'
 end
-local EXTRA_COPYRIGHT = "lua.lua (c) David Manura, 2008-08"
+local EXTRA_COPYRIGHT = "lua.lua (c) David Manura, 2008-2014"
 
 -- Note: don't allow user scripts to change implementation.
 -- Check for globals with "cat lua.lua | luac -p -l - | grep ETGLOBAL"
@@ -37,7 +37,7 @@ local _G = _G
 local assert = assert
 local collectgarbage = collectgarbage
 local loadfile = loadfile
-local loadstring = loadstring or load
+local load = load or loadstring
 local pcall = pcall
 local rawget = rawget
 local select = select
@@ -151,7 +151,7 @@ function dofile(name)
 end
 
 local function dostring(s, name)
-    local f, msg = loadstring(s, name)
+    local f, msg = load(s, name)
     if f then f, msg = docall(f) end
     return report(f, msg)
 end
@@ -178,9 +178,15 @@ local function getargs (argv, n)
 end
 
 local function get_prompt (firstline)
-  -- use rawget to play fine with require 'strict'
-    local pmt = rawget(_G, firstline and "_PROMPT" or "_PROMPT2")
-    local tp = type(pmt)
+    local pmt, tp
+    if using_lsh then
+        pmt = lsh.get_prompt(firstline)
+    end
+    if not pmt then
+      -- use rawget to play fine with require 'strict'
+        pmt = rawget(_G, firstline and "_PROMPT" or "_PROMPT2")
+    end
+    tp = type(pmt)
     if tp == "string" or tp == "number" then
         return tostring(pmt)
     end
@@ -217,28 +223,48 @@ local function pushline (firstline)
     end
 end
 
+-- Try to compile line on the stack as 'return <line>'; on return, stack
+--- has either compiled chunk or original line (if compilation failed).
+local function addreturn (b)
+    return load('return '..b,"=stdin")
+end
 
-local function loadline ()
-    local b = pushline(true)
-    if not b then return -1 end  -- no input
+-- Read multiple lines until a complete Lua statement
+local function multiline (b)
     local f, msg
     while true do  -- repeat until gets a complete line
-        f, msg = loadstring(b, "=stdin")
+        f, msg = load(b, "=stdin")
         if not incomplete(msg) then break end  -- cannot try to add lines?
         local b2 = pushline(false)
         if not b2 then -- no more input?
             return -1
         end
         b = b .. "\n" .. b2 -- join them
     end
+    return f, msg, b
+end
 
+-- Read a line and try to load (compile) it first as an expression (by
+-- adding "return " in front of it) and second as a statement. Return
+-- the final status of load/call with the resulting function (if any)
+-- in the top of the stack.  Extension: one can suppress the return
+-- by ending the expression with ';'
+local function loadline ()
+    local f,msg
+    local b = pushline(true)
+    if not b then return -1 end  -- no input
+    if not b:match ';$' then
+        f,msg = addreturn(b)
+    end
+    if not f then -- 'return ..' did not work
+        f,msg,b = multiline(b)
+    end
     saveline(b)
-
     return f, msg
 end
 
-
-local function dotty ()
+-- Do the REPL
+local function doREPL ()
     local oldprogname = progname
     progname = nil
     using_lsh,lsh = pcall(require, 'luaish')
@@ -392,11 +418,11 @@ else
 end
 
 if has.i then
-    dotty()
+    doREPL()
 elseif script == 0 and not has.e and not has.v then
     if lua_stdin_is_tty() then
         print_version()
-        dotty()
+        doREPL()
     else
         dofile(nil)  -- executes stdin as a file
     end

luaish/luaish.lua

@@ -52,6 +52,8 @@ local function expand_dollar(line,i1)
         local f = lsh.file_by_index(name)
         if not f then return end
         return {prefix..f} 
+    elseif name == '_' then -- last command
+        return {prefix..(_G['__'] or '')}
     else -- environment variable?
     	prefix = line:sub(1,i1)
         return append_candidates(nil,posix.getenv(),prefix,name)
@@ -99,9 +101,32 @@ local function lua_candidates(line)
     if mt and is_pair_iterable(mt.__index) then
         append_candidates(res,mt.__index,prefix,last)
     end
+    -- smallest matches first
+    table.sort(res,function(a,b)
+        return #a < #b
+    end)    
     return res
 end
 
+local function command_history_candidates(line)
+    local esc = at(line,1)
+    line = line:sub(1)
+    local cmd = ("grep '^%s' %s/.luai-history"):format(_G.SHELL_ESC,home)
+    local f = io.popen(cmd,'r')
+    local matches = {}
+    for line in f:lines() do
+        append(matches,line)
+    end
+    f:close()
+    local cc = {}
+    for i = #matches,1,-1 do
+        if matches[i]:sub(1,#line) == line then
+            append(cc,matches[i])
+        end
+    end
+    return cc
+end
+
 local function is_directory(path)
     return posix.stat(path,'type') == 'directory'
 end
@@ -115,6 +140,9 @@ local function path_candidates(line)
     elseif not i1 then
         return
     end
+    if line:match '^.[%w_]+$' then
+        return command_history_candidates(line)    
+    end
     front, path = line:sub(1,i1-1), line:sub(i1)
     i1 = path:find '[.%w_%-]*$'
     if not i1 then return end
@@ -136,7 +164,7 @@ local function path_candidates(line)
     local res = {}
     local all = name == ''
     for _,f in ipairs(posix.dir(path)) do 
-        if all or f:sub(1,#name)==name then
+        if not (f=='.' or f=='..') and (all or f:sub(1,#name)==name) then
             push(res,front..dpath..f)
         end
     end
@@ -147,9 +175,22 @@ local function path_candidates(line)
     return res
 end
 
+local auto_shell_mode
+
+local function shell_mode(s)
+    return at(s,1) == _G.SHELL_ESC or auto_shell_mode
+end
+
+function lsh.get_prompt(firstline)
+    if not auto_shell_mode then return nil
+    else
+        return '$> '
+    end
+end
+
 local function completion_handler(c,s)
     local cc
-    if at(s,1) == SHELL_ESC then -- shell path completion
+    if shell_mode(s) then -- shell path completion
         cc = path_candidates(s)
         if not cc then return end
     else -- otherwise Lua...
@@ -185,7 +226,7 @@ end
 
 function lsh.add_completion(pat,cf)
     our_completions[pat] = cf
-end  
+end
 
 local file_list = {}
 
@@ -238,7 +279,7 @@ end
 local shell_command_handler
 
 function lsh.checkline(b)
-    if at(b,1) == _G.SHELL_ESC then
+    if shell_mode(b) then
         local err, res = pcall(shell_command_handler,b)
         if not err then
             print('luaish error',res)
@@ -294,7 +335,6 @@ lsh.print = function(f,name)
     end
 end
 
-
 --- managing directory stack----
 local dirstack = {}
 
@@ -386,6 +426,12 @@ function lsh.add_alias(name,cmd)
     alias[name] = cmd
 end
 
+function lsh.show_aliases()
+    for k,v in pairs(alias) do
+        print(k,v)
+    end
+end
+
 local function expand_lua_globals(line)    
     return line:gsub('%$([%w_]+)',function(name)
         if name == '_' then name = '__' end
@@ -397,8 +443,19 @@ local function expand_lua_globals(line)
 end
 
 function shell_command_handler (line)
-    line = line:sub(2)
+    if not auto_shell_mode then
+        line = line:sub(2)
+    end
     line = line:gsub ('^%s*','')
+    if line == "" then
+        auto_shell_mode = true
+        return true
+    elseif line == 'exit' then
+        if auto_shell_mode then
+            auto_shell_mode = false
+        end
+        return true
+    end
     line = expand_lua_globals(line)
     local cmd,args = line:match '^(%S+)%s*(.*)$'
     if not args then
@@ -460,6 +517,10 @@ function shell_command_handler (line)
         local cmd = (('%s && echo %s \\"$%s\\" |-lsetenv'):format(args,var,var))
         return exec(cmd)
     elseif cmd == 'set' then
+        if args:match '^%s*$' then
+            lsh.show_aliases()
+            return true
+        end        
         local name,exp = args:match '(%S+)%s+(.+)'
         if not name then
             print("syntax is 'set name command'")
@@ -491,14 +552,14 @@ ok,_G.config = pcall(require,'config')
 lsh.set_shortcut ('fn', "function ")
 lsh.set_shortcut('rt','return')
 
-_G.SHELL_ESC='.'
+_G.SHELL_ESC='!'
 _G.posix = posix
 _G.luaish = lsh -- global for rc file
 
 local data
 
 if not safe_dofile(home..'/.luairc.lua') then
-    print("customize with ~/.luaric.lua")
+    print("customize with ~/.luairc.lua")
 end
 local pfile = home..'/.luai-data'
 local chunk = loadfile(pfile)