--- /dev/null
+------------------------------------------------------------------------------
+-- Copyright (c) 2006-2013 Fabien Fleutot and others.
+--
+-- All rights reserved.
+--
+-- This program and the accompanying materials are made available
+-- under the terms of the Eclipse Public License v1.0 which
+-- accompanies this distribution, and is available at
+-- http://www.eclipse.org/legal/epl-v10.html
+--
+-- This program and the accompanying materials are also made available
+-- under the terms of the MIT public license which accompanies this
+-- distribution, and is available at http://www.lua.org/license.html
+--
+-- Contributors:
+-- Fabien Fleutot - API and implementation
+--
+-------------------------------------------------------------------------------
+
+-------------------------------------------------------------------------------
+--
+-- Summary: metalua parser, statement/block parser. This is part of the
+-- definition of module [mlp].
+--
+-------------------------------------------------------------------------------
+
+-------------------------------------------------------------------------------
+--
+-- Exports API:
+-- * [mlp.stat()]
+-- * [mlp.block()]
+-- * [mlp.for_header()]
+--
+-------------------------------------------------------------------------------
+
+local lexer = require 'metalua.grammar.lexer'
+local gg = require 'metalua.grammar.generator'
+
+local annot = require 'metalua.compiler.parser.annot.generator'
+
+--------------------------------------------------------------------------------
+-- List of all keywords that indicate the end of a statement block. Users are
+-- likely to extend this list when designing extensions.
+--------------------------------------------------------------------------------
+
+
+return function(M)
+ local _M = gg.future(M)
+
+ M.block_terminators = { "else", "elseif", "end", "until", ")", "}", "]" }
+
+ -- FIXME: this must be handled from within GG!!!
+ -- FIXME: there's no :add method in the list anyway. Added by gg.list?!
+ function M.block_terminators :add(x)
+ if type (x) == "table" then for _, y in ipairs(x) do self :add (y) end
+ else table.insert (self, x) end
+ end
+
+ ----------------------------------------------------------------------------
+ -- list of statements, possibly followed by semicolons
+ ----------------------------------------------------------------------------
+ M.block = gg.list {
+ name = "statements block",
+ terminators = M.block_terminators,
+ primary = function (lx)
+ -- FIXME use gg.optkeyword()
+ local x = M.stat (lx)
+ if lx:is_keyword (lx:peek(), ";") then lx:next() end
+ return x
+ end }
+
+ ----------------------------------------------------------------------------
+ -- Helper function for "return <expr_list>" parsing.
+ -- Called when parsing return statements.
+ -- The specific test for initial ";" is because it's not a block terminator,
+ -- so without it gg.list would choke on "return ;" statements.
+ -- We don't make a modified copy of block_terminators because this list
+ -- is sometimes modified at runtime, and the return parser would get out of
+ -- sync if it was relying on a copy.
+ ----------------------------------------------------------------------------
+ local return_expr_list_parser = gg.multisequence{
+ { ";" , builder = function() return { } end },
+ default = gg.list {
+ _M.expr, separators = ",", terminators = M.block_terminators } }
+
+
+ local for_vars_list = gg.list{
+ name = "for variables list",
+ primary = _M.id,
+ separators = ",",
+ terminators = "in" }
+
+ ----------------------------------------------------------------------------
+ -- for header, between [for] and [do] (exclusive).
+ -- Return the `Forxxx{...} AST, without the body element (the last one).
+ ----------------------------------------------------------------------------
+ function M.for_header (lx)
+ local vars = M.id_list(lx)
+ if lx :is_keyword (lx:peek(), "=") then
+ if #vars ~= 1 then
+ gg.parse_error (lx, "numeric for only accepts one variable")
+ end
+ lx:next() -- skip "="
+ local exprs = M.expr_list (lx)
+ if #exprs < 2 or #exprs > 3 then
+ gg.parse_error (lx, "numeric for requires 2 or 3 boundaries")
+ end
+ return { tag="Fornum", vars[1], unpack (exprs) }
+ else
+ if not lx :is_keyword (lx :next(), "in") then
+ gg.parse_error (lx, '"=" or "in" expected in for loop')
+ end
+ local exprs = M.expr_list (lx)
+ return { tag="Forin", vars, exprs }
+ end
+ end
+
+ ----------------------------------------------------------------------------
+ -- Function def parser helper: id ( . id ) *
+ ----------------------------------------------------------------------------
+ local function fn_builder (list)
+ local acc = list[1]
+ local first = acc.lineinfo.first
+ for i = 2, #list do
+ local index = M.id2string(list[i])
+ local li = lexer.new_lineinfo(first, index.lineinfo.last)
+ acc = { tag="Index", acc, index, lineinfo=li }
+ end
+ return acc
+ end
+ local func_name = gg.list{ _M.id, separators = ".", builder = fn_builder }
+
+ ----------------------------------------------------------------------------
+ -- Function def parser helper: ( : id )?
+ ----------------------------------------------------------------------------
+ local method_name = gg.onkeyword{ name = "method invocation", ":", _M.id,
+ transformers = { function(x) return x and x.tag=='Id' and M.id2string(x) end } }
+
+ ----------------------------------------------------------------------------
+ -- Function def builder
+ ----------------------------------------------------------------------------
+ local function funcdef_builder(x)
+ local name, method, func = unpack(x)
+ if method then
+ name = { tag="Index", name, method,
+ lineinfo = {
+ first = name.lineinfo.first,
+ last = method.lineinfo.last } }
+ table.insert (func[1], 1, {tag="Id", "self"})
+ end
+ local r = { tag="Set", {name}, {func} }
+ r[1].lineinfo = name.lineinfo
+ r[2].lineinfo = func.lineinfo
+ return r
+ end
+
+
+ ----------------------------------------------------------------------------
+ -- if statement builder
+ ----------------------------------------------------------------------------
+ local function if_builder (x)
+ local cond_block_pairs, else_block, r = x[1], x[2], {tag="If"}
+ local n_pairs = #cond_block_pairs
+ for i = 1, n_pairs do
+ local cond, block = unpack(cond_block_pairs[i])
+ r[2*i-1], r[2*i] = cond, block
+ end
+ if else_block then table.insert(r, #r+1, else_block) end
+ return r
+ end
+
+ --------------------------------------------------------------------------------
+ -- produce a list of (expr,block) pairs
+ --------------------------------------------------------------------------------
+ local elseifs_parser = gg.list {
+ gg.sequence { _M.expr, "then", _M.block , name='elseif parser' },
+ separators = "elseif",
+ terminators = { "else", "end" }
+ }
+
+ local annot_expr = gg.sequence {
+ _M.expr,
+ gg.onkeyword{ "#", gg.future(M, 'annot').tf },
+ builder = function(x)
+ local e, a = unpack(x)
+ if a then return { tag='Annot', e, a }
+ else return e end
+ end }
+
+ local annot_expr_list = gg.list {
+ primary = annot.opt(M, _M.expr, 'tf'), separators = ',' }
+
+ ------------------------------------------------------------------------
+ -- assignments and calls: statements that don't start with a keyword
+ ------------------------------------------------------------------------
+ local function assign_or_call_stat_parser (lx)
+ local e = annot_expr_list (lx)
+ local a = lx:is_keyword(lx:peek())
+ local op = a and M.assignments[a]
+ -- TODO: refactor annotations
+ if op then
+ --FIXME: check that [e] is a LHS
+ lx :next()
+ local annots
+ e, annots = annot.split(e)
+ local v = M.expr_list (lx)
+ if type(op)=="string" then return { tag=op, e, v, annots }
+ else return op (e, v) end
+ else
+ assert (#e > 0)
+ if #e > 1 then
+ gg.parse_error (lx,
+ "comma is not a valid statement separator; statement can be "..
+ "separated by semicolons, or not separated at all")
+ elseif e[1].tag ~= "Call" and e[1].tag ~= "Invoke" then
+ local typename
+ if e[1].tag == 'Id' then
+ typename = '("'..e[1][1]..'") is an identifier'
+ elseif e[1].tag == 'Op' then
+ typename = "is an arithmetic operation"
+ else typename = "is of type '"..(e[1].tag or "<list>").."'" end
+ gg.parse_error (lx,
+ "This expression %s; "..
+ "a statement was expected, and only function and method call "..
+ "expressions can be used as statements", typename);
+ end
+ return e[1]
+ end
+ end
+
+ M.local_stat_parser = gg.multisequence{
+ -- local function <name> <func_val>
+ { "function", _M.id, _M.func_val, builder =
+ function(x)
+ local vars = { x[1], lineinfo = x[1].lineinfo }
+ local vals = { x[2], lineinfo = x[2].lineinfo }
+ return { tag="Localrec", vars, vals }
+ end },
+ -- local <id_list> ( = <expr_list> )?
+ default = gg.sequence{
+ gg.list{
+ primary = annot.opt(M, _M.id, 'tf'),
+ separators = ',' },
+ gg.onkeyword{ "=", _M.expr_list },
+ builder = function(x)
+ local annotated_left, right = unpack(x)
+ local left, annotations = annot.split(annotated_left)
+ return {tag="Local", left, right or { }, annotations }
+ end } }
+
+ ------------------------------------------------------------------------
+ -- statement
+ ------------------------------------------------------------------------
+ M.stat = gg.multisequence {
+ name = "statement",
+ { "do", _M.block, "end", builder =
+ function (x) return { tag="Do", unpack (x[1]) } end },
+ { "for", _M.for_header, "do", _M.block, "end", builder =
+ function (x) x[1][#x[1]+1] = x[2]; return x[1] end },
+ { "function", func_name, method_name, _M.func_val, builder=funcdef_builder },
+ { "while", _M.expr, "do", _M.block, "end", builder = "While" },
+ { "repeat", _M.block, "until", _M.expr, builder = "Repeat" },
+ { "local", _M.local_stat_parser, builder = unpack },
+ { "return", return_expr_list_parser, builder =
+ function(x) x[1].tag='Return'; return x[1] end },
+ { "break", builder = function() return { tag="Break" } end },
+ { "-{", gg.future(M, 'meta').splice_content, "}", builder = unpack },
+ { "if", gg.nonempty(elseifs_parser), gg.onkeyword{ "else", M.block }, "end",
+ builder = if_builder },
+ default = assign_or_call_stat_parser }
+
+ M.assignments = {
+ ["="] = "Set"
+ }
+
+ function M.assignments:add(k, v) self[k] = v end
+
+ return M
+end
\ No newline at end of file
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