+ LuaMacro

1 files changed, 59 insertions, 0 deletions

diff --git a/Tools/LuaMacro/tests/list.lua b/Tools/LuaMacro/tests/list.lua
new file mode 100644
index 0000000..274d482
--- /dev/null
+++ b/Tools/LuaMacro/tests/list.lua
@@ -0,0 +1,59 @@
+local M = require 'macro'

+List = require 'pl.List'

+

+local list_check

+

+-- list <var-list> [ = <init-list> ]

+-- acts as a 'macro factory', making locally-scoped macros for the variables,

+-- and emitting code to initialize plain variables.

+M.define ('list',function(get)

+    get() -- skip space

+    -- 'list' acts as a 'type' followed by a variable list, which may be

+    -- followed by initial values

+    local values

+    local vars,endt = get:idens (function(t,v)

+        return t == '=' or (t == 'space' and v:find '\n')

+    end)

+    -- there is an initialization list

+    if endt[1] == '=' then

+        values,endt = get:list '\n'

+    else

+        values = {}

+    end

+    -- build up the initialization list

+    for i,name in ipairs(vars) do

+       M.define_scoped(name,list_check)

+       values[i] = 'List('..tostring(values[i] or '')..')'

+    end

+    local lcal = M._interactive and '' or 'local '

+    local res = lcal..table.concat(vars,',')..' = '..table.concat(values,',')..tostring(endt)

+    return res

+end)

+

+function list_check (get,put)

+    local t,v = get:peek(1)

+    if t ~= '[' then return nil, true end -- pass-through; plain var reference

+    get:expecting '['

+    local args = get:list(']',':')

+    -- it's just plain table access

+    if #args == 1 then return '['..tostring(args[1])..']',true end

+

+    -- two items separated by a colon; use sensible defaults

+    M.assert(#args == 2, "slice has two arguments!")

+    local start,finish = tostring(args[1]),tostring(args[2])

+    if start == '' then start = '1' end

+    if finish == '' then finish = '-1' end

+

+    -- look ahead to see if we're on the left hand side of an assignment

+    if get:peek(1) == '=' then

+       get:next() -- skip '='

+       local rest,eoln = get:upto '\n'

+       rest,eoln = tostring(rest),tostring(eoln)

+       return (':slice_assign(%s,%s,%s)%s'):format(start,finish,rest,eoln),true

+    else

+        return (':slice(%s,%s)'):format(start,finish),true

+    end

+end

+

+

+