if not modules then modules = { } end modules ['syst-lua'] = {
version = 1.001,
comment = "companion to syst-lua.mkiv",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
local find = string.find
local S, C, P, lpegmatch, lpegtsplitat = lpeg.S, lpeg.C, lpeg.P, lpeg.match, lpeg.tsplitat
commands = commands or { }
local commands = commands
local context = context
local implement = interfaces.implement
local ctx_protected_cs = context.protected.cs -- more efficient
local ctx_firstoftwoarguments = context.firstoftwoarguments
local ctx_secondoftwoarguments = context.secondoftwoarguments
local ctx_firstofoneargument = context.firstofoneargument
local ctx_gobbleoneargument = context.gobbleoneargument
local two_strings = interfaces.strings[2]
implement { -- will be overloaded later
name = "writestatus",
arguments = two_strings,
actions = logs.status,
}
function commands.doifelse(b)
if b then
ctx_firstoftwoarguments()
else
ctx_secondoftwoarguments()
end
end
function commands.doifelsesomething(b)
if b and b ~= "" then
ctx_firstoftwoarguments()
else
ctx_secondoftwoarguments()
end
end
function commands.doif(b)
if b then
ctx_firstofoneargument()
else
ctx_gobbleoneargument()
end
end
function commands.doifsomething(b)
if b and b ~= "" then
ctx_firstofoneargument()
else
ctx_gobbleoneargument()
end
end
function commands.doifnot(b)
if b then
ctx_gobbleoneargument()
else
ctx_firstofoneargument()
end
end
function commands.doifnotthing(b)
if b and b ~= "" then
ctx_gobbleoneargument()
else
ctx_firstofoneargument()
end
end
commands.testcase = commands.doifelse -- obsolete
function commands.boolcase(b)
context(b and 1 or 0)
end
function commands.doifelsespaces(str)
if find(str,"^ +$") then
ctx_firstoftwoarguments()
else
ctx_secondoftwoarguments()
end
end
local pattern = lpeg.patterns.validdimen
function commands.doifelsedimenstring(str)
if lpegmatch(pattern,str) then
ctx_firstoftwoarguments()
else
ctx_secondoftwoarguments()
end
end
local p_first = C((1-P(",")-P(-1))^0)
implement {
name = "firstinset",
arguments = "string",
actions = function(str) context(lpegmatch(p_first,str or "")) end,
public = true,
}
implement {
name = "ntimes",
arguments = { "string", "integer" },
actions = { string.rep, context }
}
implement {
name = "execute",
arguments = "string",
actions = os.execute -- wrapped in sandbox
}
implement {
name = "doifelsesame",
arguments = two_strings,
actions = function(a,b)
if a == b then
ctx_firstoftwoarguments()
else
ctx_secondoftwoarguments()
end
end
}
implement {
name = "doifsame",
arguments = two_strings,
actions = function(a,b)
if a == b then
ctx_firstofoneargument()
else
ctx_gobbleoneargument()
end
end
}
implement {
name = "doifnotsame",
arguments = two_strings,
actions = function(a,b)
if a == b then
ctx_gobbleoneargument()
else
ctx_firstofoneargument()
end
end
}
-- This is a bit of a joke as I never really needed floating point expressions (okay,
-- maybe only with scaling because there one can get numbers that are too large for
-- dimensions to deal with). Of course one can write a parser in \TEX\ speak but then
-- one also needs to implement a bunch of functions. It doesn't pay of so we just
-- stick to the next gimmick. It looks inefficient but performance is actually quite
-- efficient.
local concat = table.concat
local utfchar = utf.char
local load, type, tonumber = load, type, tonumber
local xmath = xmath or math
local xcomplex = xcomplex or { }
local cmd = tokens.commands
local get_next = token.get_next
local get_command = token.get_command
local get_mode = token.get_mode
local get_index = token.get_index
local get_csname = token.get_csname
local get_macro = token.get_macro
local put_next = token.put_next
local scan_token = token.scan_token
local getdimen = tex.getdimen
local getglue = tex.getglue
local getcount = tex.getcount
local gettoks = tex.gettoks
local gettex = tex.get
local context = context
local dimenfactors = number.dimenfactors
local result = { "return " }
local word = { }
local r = 1
local w = 0
local report = logs.reporter("system","expression")
local function unexpected(c)
report("unexpected token %a",c)
end
local function expression()
local w = 0
local r = 1
while true do
local t = get_next()
local n = get_command(t)
local c = cmd[n]
-- todo, helper: returns number
if c == "letter" then
w = w + 1 ; word[w] = utfchar(get_mode(t))
else
if w > 0 then
local s = concat(word,"",1,w)
local d = dimenfactors[s]
if d then
r = r + 1 ; result[r] = "*"
r = r + 1 ; result[r] = 1/d
else
if xmath[s] then
r = r + 1 ; result[r] = "xmath."
elseif xcomplex[s] then
r = r + 1 ; result[r] = "xcomplex."
end
r = r + 1 ; result[r] = s
end
w = 0
end
if c == "other_char" then
r = r + 1 ; result[r] = utfchar(get_mode(t))
elseif c == "spacer" then
-- r = r + 1 ; result[r] = " "
elseif c == "relax" then
break
elseif c == "assign_int" then
r = r + 1 ; result[r] = getcount(get_index(t))
elseif c == "assign_dimen" then
r = r + 1 ; result[r] = getdimen(get_index(t))
elseif c == "assign_glue" then
r = r + 1 ; result[r] = getglue(get_index(t))
elseif c == "assign_toks" then
r = r + 1 ; result[r] = gettoks(get_index(t))
elseif c == "char_given" or c == "math_given" or c == "xmath_given" then
r = r + 1 ; result[r] = get_mode(t)
elseif c == "last_item" then
local n = get_csname(t)
if n then
local s = gettex(n)
if s then
r = r + 1 ; result[r] = s
else
unexpected(c)
end
else
unexpected(c)
end
elseif c == "call" then
local n = get_csname(t)
if n then
local s = get_macro(n)
if s then
r = r + 1 ; result[r] = s
else
unexpected(c)
end
else
unexpected(c)
end
elseif c == "the" or c == "convert" or c == "lua_expandable_call" then
put_next(t)
scan_token() -- expands
else
unexpected(c)
end
end
end
local code = concat(result,"",1,r)
local func = load(code)
if type(func) == "function" then
context(func())
else
report("invalid lua %a",code)
end
end
-- local letter_code <const> = cmd.letter
-- local other_char_code <const> = cmd.other_char
-- local spacer_code <const> = cmd.spacer
-- local other_char_code <const> = cmd.other_char
-- local relax_code <const> = cmd.relax
-- local assign_int_code <const> = cmd.assign_int
-- local assign_dimen_code <const> = cmd.assign_dimen
-- local assign_glue_code <const> = cmd.assign_glue
-- local assign_toks_code <const> = cmd.assign_toks
-- local char_given_code <const> = cmd.char_given
-- local math_given_code <const> = cmd.math_given
-- local xmath_given_code <const> = cmd.xmath_given
-- local last_item_code <const> = cmd.last_item
-- local call_code <const> = cmd.call
-- local the_code <const> = cmd.the
-- local convert_code <const> = cmd.convert
-- local lua_expandable_call_code <const> = cmd.lua_expandable_call
--
-- local function unexpected(c)
-- report("unexpected token %a",c)
-- end
--
-- local function expression()
-- local w = 0
-- local r = 1
-- while true do
-- local t = get_next()
-- local n = get_command(t)
-- if n == letter_code then
-- w = w + 1 ; word[w] = utfchar(get_mode(t))
-- else
-- if w > 0 then
-- -- we could use a metatable for all math, complex and factors
-- local s = concat(word,"",1,w)
-- local d = dimenfactors[s]
-- if d then
-- r = r + 1 ; result[r] = "*"
-- r = r + 1 ; result[r] = 1/d
-- else
-- if xmath[s] then
-- r = r + 1 ; result[r] = "xmath."
-- elseif xcomplex[s] then
-- r = r + 1 ; result[r] = "xcomplex."
-- end
-- r = r + 1 ; result[r] = s
-- end
-- w = 0
-- end
-- if n == other_char_code then
-- r = r + 1 ; result[r] = utfchar(get_mode(t))
-- elseif n == spacer_code then
-- -- r = r + 1 ; result[r] = " "
-- elseif n == relax_code then
-- break
-- elseif n == assign_int_code then
-- r = r + 1 ; result[r] = getcount(get_index(t))
-- elseif n == assign_dimen_code then
-- r = r + 1 ; result[r] = getdimen(get_index(t))
-- elseif n == assign_glue_code then
-- r = r + 1 ; result[r] = getglue(get_index(t))
-- elseif n == assign_toks_code then
-- r = r + 1 ; result[r] = gettoks(get_index(t))
-- elseif n == char_given_code or n == math_given_code or n == xmath_given_code then
-- r = r + 1 ; result[r] = get_mode(t)
-- elseif n == last_item_code then
-- local n = get_csname(t)
-- if n then
-- local s = gettex(n)
-- if s then
-- r = r + 1 ; result[r] = s
-- else
-- unexpected(c)
-- end
-- else
-- unexpected(c)
-- end
-- elseif n == call_code then
-- local n = get_csname(t)
-- if n then
-- local s = get_macro(n)
-- if s then
-- r = r + 1 ; result[r] = s
-- else
-- unexpected(c)
-- end
-- else
-- unexpected(c)
-- end
-- elseif n == the_code or n == convert_code or n == lua_expandable_call_code then
-- put_next(t)
-- scan_token() -- expands
-- else
-- unexpected(c)
-- end
-- end
-- end
-- local code = concat(result,"",1,r)
-- local func = load(code)
-- if type(func) == "function" then
-- context(func())
-- else
-- report("invalid lua %a",code)
-- end
-- end
implement {
public = true,
name = "expression",
actions = expression,
}
