Compatible Android
This commit is contained in:
Andros Fenollosa
@ -0,0 +1,832 @@
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--------------------------------------------------------------------------------
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-- Copyright (c) 2006-2013 Fabien Fleutot and others.
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--
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-- All rights reserved.
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--
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-- This program and the accompanying materials are made available
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-- under the terms of the Eclipse Public License v1.0 which
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-- accompanies this distribution, and is available at
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-- http://www.eclipse.org/legal/epl-v10.html
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--
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-- This program and the accompanying materials are also made available
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-- under the terms of the MIT public license which accompanies this
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-- distribution, and is available at http://www.lua.org/license.html
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--
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-- Contributors:
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-- Fabien Fleutot - API and implementation
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--
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--------------------------------------------------------------------------------
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--------------------------------------------------------------------------------
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--
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-- Summary: parser generator. Collection of higher order functors,
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-- which allow to build and combine parsers. Relies on a lexer
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-- that supports the same API as the one exposed in mll.lua.
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--
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--------------------------------------------------------------------------------
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--------------------------------------------------------------------------------
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--
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-- Exported API:
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--
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-- Parser generators:
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-- * [gg.sequence()]
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-- * [gg.multisequence()]
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-- * [gg.expr()]
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-- * [gg.list()]
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-- * [gg.onkeyword()]
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-- * [gg.optkeyword()]
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--
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-- Other functions:
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-- * [gg.parse_error()]
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-- * [gg.make_parser()]
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-- * [gg.is_parser()]
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--
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--------------------------------------------------------------------------------
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local M = { }
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local lexer = require 'metalua.grammar.lexer'
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--------------------------------------------------------------------------------
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-- Symbol generator: [gensym()] returns a guaranteed-to-be-unique identifier.
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-- The main purpose is to avoid variable capture in macros.
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--
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-- If a string is passed as an argument, theis string will be part of the
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-- id name (helpful for macro debugging)
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--------------------------------------------------------------------------------
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local gensymidx = 0
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function M.gensym (arg)
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gensymidx = gensymidx + 1
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return { tag="Id", string.format(".%i.%s", gensymidx, arg or "")}
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end
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-------------------------------------------------------------------------------
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-- parser metatable, which maps __call to method parse, and adds some
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-- error tracing boilerplate.
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-------------------------------------------------------------------------------
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local parser_metatable = { }
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function parser_metatable :__call (lx, ...)
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return self :parse (lx, ...)
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end
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-------------------------------------------------------------------------------
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-- Turn a table into a parser, mainly by setting the metatable.
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-------------------------------------------------------------------------------
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function M.make_parser(kind, p)
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p.kind = kind
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if not p.transformers then p.transformers = { } end
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function p.transformers:add (x)
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table.insert (self, x)
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end
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setmetatable (p, parser_metatable)
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return p
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end
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-------------------------------------------------------------------------------
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-- Return true iff [x] is a parser.
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-- If it's a gg-generated parser, return the name of its kind.
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-------------------------------------------------------------------------------
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function M.is_parser (x)
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return type(x)=="function" or getmetatable(x)==parser_metatable and x.kind
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end
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-------------------------------------------------------------------------------
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-- Parse a sequence, without applying builder nor transformers.
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-------------------------------------------------------------------------------
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local function raw_parse_sequence (lx, p)
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local r = { }
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for i=1, #p do
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local e=p[i]
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if type(e) == "string" then
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local kw = lx :next()
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if not lx :is_keyword (kw, e) then
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M.parse_error(
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lx, "A keyword was expected, probably `%s'.", e)
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end
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elseif M.is_parser (e) then
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table.insert (r, e(lx))
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else -- Invalid parser definition, this is *not* a parsing error
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error(string.format(
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"Sequence `%s': element #%i is neither a string nor a parser: %s",
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p.name, i, table.tostring(e)))
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end
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end
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return r
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end
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-------------------------------------------------------------------------------
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-- Parse a multisequence, without applying multisequence transformers.
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-- The sequences are completely parsed.
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-------------------------------------------------------------------------------
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local function raw_parse_multisequence (lx, sequence_table, default)
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local seq_parser = sequence_table[lx:is_keyword(lx:peek())]
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if seq_parser then return seq_parser (lx)
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elseif default then return default (lx)
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else return false end
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end
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-------------------------------------------------------------------------------
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-- Applies all transformers listed in parser on ast.
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-------------------------------------------------------------------------------
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local function transform (ast, parser, fli, lli)
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if parser.transformers then
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for _, t in ipairs (parser.transformers) do ast = t(ast) or ast end
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end
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if type(ast) == 'table' then
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local ali = ast.lineinfo
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if not ali or ali.first~=fli or ali.last~=lli then
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ast.lineinfo = lexer.new_lineinfo(fli, lli)
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end
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end
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return ast
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end
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-------------------------------------------------------------------------------
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-- Generate a tracable parsing error (not implemented yet)
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-------------------------------------------------------------------------------
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function M.parse_error(lx, fmt, ...)
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local li = lx:lineinfo_left()
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local file, line, column, offset, positions
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if li then
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file, line, column, offset = li.source, li.line, li.column, li.offset
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positions = { first = li, last = li }
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else
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line, column, offset = -1, -1, -1
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end
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local msg = string.format("line %i, char %i: "..fmt, line, column, ...)
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if file and file~='?' then msg = "file "..file..", "..msg end
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local src = lx.src
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if offset>0 and src then
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local i, j = offset, offset
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while src:sub(i,i) ~= '\n' and i>=0 do i=i-1 end
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while src:sub(j,j) ~= '\n' and j<=#src do j=j+1 end
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local srcline = src:sub (i+1, j-1)
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local idx = string.rep (" ", column).."^"
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msg = string.format("%s\n>>> %s\n>>> %s", msg, srcline, idx)
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end
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--lx :kill()
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error(msg)
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end
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-------------------------------------------------------------------------------
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--
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-- Sequence parser generator
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--
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-------------------------------------------------------------------------------
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-- Input fields:
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--
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-- * [builder]: how to build an AST out of sequence parts. let [x] be the list
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-- of subparser results (keywords are simply omitted). [builder] can be:
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-- - [nil], in which case the result of parsing is simply [x]
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-- - a string, which is then put as a tag on [x]
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-- - a function, which takes [x] as a parameter and returns an AST.
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--
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-- * [name]: the name of the parser. Used for debug messages
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--
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-- * [transformers]: a list of AST->AST functions, applied in order on ASTs
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-- returned by the parser.
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--
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-- * Table-part entries corresponds to keywords (strings) and subparsers
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-- (function and callable objects).
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--
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-- After creation, the following fields are added:
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-- * [parse] the parsing function lexer->AST
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-- * [kind] == "sequence"
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-- * [name] is set, if it wasn't in the input.
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--
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-------------------------------------------------------------------------------
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function M.sequence (p)
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M.make_parser ("sequence", p)
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-------------------------------------------------------------------
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-- Parsing method
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-------------------------------------------------------------------
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function p:parse (lx)
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-- Raw parsing:
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local fli = lx:lineinfo_right()
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local seq = raw_parse_sequence (lx, self)
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local lli = lx:lineinfo_left()
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-- Builder application:
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local builder, tb = self.builder, type (self.builder)
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if tb == "string" then seq.tag = builder
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elseif tb == "function" or builder and builder.__call then seq = builder(seq)
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elseif builder == nil then -- nothing
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else error ("Invalid builder of type "..tb.." in sequence") end
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seq = transform (seq, self, fli, lli)
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assert (not seq or seq.lineinfo)
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return seq
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end
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-------------------------------------------------------------------
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-- Construction
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-------------------------------------------------------------------
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-- Try to build a proper name
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if p.name then
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-- don't touch existing name
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elseif type(p[1])=="string" then -- find name based on 1st keyword
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if #p==1 then p.name=p[1]
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elseif type(p[#p])=="string" then
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p.name = p[1] .. " ... " .. p[#p]
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else p.name = p[1] .. " ..." end
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else -- can't find a decent name
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p.name = "unnamed_sequence"
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end
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return p
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end --</sequence>
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-------------------------------------------------------------------------------
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--
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-- Multiple, keyword-driven, sequence parser generator
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--
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-------------------------------------------------------------------------------
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-- in [p], useful fields are:
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--
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-- * [transformers]: as usual
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--
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-- * [name]: as usual
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--
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-- * Table-part entries must be sequence parsers, or tables which can
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-- be turned into a sequence parser by [gg.sequence]. These
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-- sequences must start with a keyword, and this initial keyword
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-- must be different for each sequence. The table-part entries will
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-- be removed after [gg.multisequence] returns.
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--
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-- * [default]: the parser to run if the next keyword in the lexer is
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-- none of the registered initial keywords. If there's no default
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-- parser and no suitable initial keyword, the multisequence parser
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-- simply returns [false].
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--
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-- After creation, the following fields are added:
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--
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-- * [parse] the parsing function lexer->AST
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--
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-- * [sequences] the table of sequences, indexed by initial keywords.
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--
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-- * [add] method takes a sequence parser or a config table for
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-- [gg.sequence], and adds/replaces the corresponding sequence
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-- parser. If the keyword was already used, the former sequence is
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-- removed and a warning is issued.
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--
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-- * [get] method returns a sequence by its initial keyword
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--
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-- * [kind] == "multisequence"
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--
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-------------------------------------------------------------------------------
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function M.multisequence (p)
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M.make_parser ("multisequence", p)
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-------------------------------------------------------------------
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-- Add a sequence (might be just a config table for [gg.sequence])
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-------------------------------------------------------------------
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function p :add (s)
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-- compile if necessary:
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local keyword = type(s)=='table' and s[1]
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if type(s)=='table' and not M.is_parser(s) then M.sequence(s) end
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if M.is_parser(s)~='sequence' or type(keyword)~='string' then
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if self.default then -- two defaults
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error ("In a multisequence parser, all but one sequences "..
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"must start with a keyword")
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else self.default = s end -- first default
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else
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if self.sequences[keyword] then -- duplicate keyword
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-- TODO: warn that initial keyword `keyword` is overloaded in multiseq
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end
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self.sequences[keyword] = s
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end
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end -- </multisequence.add>
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-------------------------------------------------------------------
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-- Get the sequence starting with this keyword. [kw :: string]
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-------------------------------------------------------------------
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function p :get (kw) return self.sequences [kw] end
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-------------------------------------------------------------------
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-- Remove the sequence starting with keyword [kw :: string]
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-------------------------------------------------------------------
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function p :del (kw)
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if not self.sequences[kw] then
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-- TODO: warn that we try to delete a non-existent entry
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end
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local removed = self.sequences[kw]
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self.sequences[kw] = nil
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return removed
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end
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-------------------------------------------------------------------
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-- Parsing method
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-------------------------------------------------------------------
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function p :parse (lx)
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local fli = lx:lineinfo_right()
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local x = raw_parse_multisequence (lx, self.sequences, self.default)
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local lli = lx:lineinfo_left()
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return transform (x, self, fli, lli)
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end
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-------------------------------------------------------------------
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-- Construction
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-------------------------------------------------------------------
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-- Register the sequences passed to the constructor. They're going
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-- from the array part of the parser to the hash part of field
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-- [sequences]
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p.sequences = { }
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for i=1, #p do p :add (p[i]); p[i] = nil end
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-- FIXME: why is this commented out?
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--if p.default and not is_parser(p.default) then sequence(p.default) end
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return p
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end --</multisequence>
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-------------------------------------------------------------------------------
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--
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-- Expression parser generator
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--
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-------------------------------------------------------------------------------
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--
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-- Expression configuration relies on three tables: [prefix], [infix]
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-- and [suffix]. Moreover, the primary parser can be replaced by a
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-- table: in this case the [primary] table will be passed to
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-- [gg.multisequence] to create a parser.
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--
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-- Each of these tables is a modified multisequence parser: the
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-- differences with respect to regular multisequence config tables are:
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--
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-- * the builder takes specific parameters:
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-- - for [prefix], it takes the result of the prefix sequence parser,
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-- and the prefixed expression
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-- - for [infix], it takes the left-hand-side expression, the results
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-- of the infix sequence parser, and the right-hand-side expression.
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-- - for [suffix], it takes the suffixed expression, and the result
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-- of the suffix sequence parser.
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--
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-- * the default field is a list, with parameters:
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-- - [parser] the raw parsing function
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-- - [transformers], as usual
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-- - [prec], the operator's precedence
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-- - [assoc] for [infix] table, the operator's associativity, which
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-- can be "left", "right" or "flat" (default to left)
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--
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-- In [p], useful fields are:
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-- * [transformers]: as usual
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-- * [name]: as usual
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-- * [primary]: the atomic expression parser, or a multisequence config
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-- table (mandatory)
|
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-- * [prefix]: prefix operators config table, see above.
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-- * [infix]: infix operators config table, see above.
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-- * [suffix]: suffix operators config table, see above.
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--
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-- After creation, these fields are added:
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-- * [kind] == "expr"
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-- * [parse] as usual
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-- * each table is turned into a multisequence, and therefore has an
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-- [add] method
|
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--
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-------------------------------------------------------------------------------
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function M.expr (p)
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M.make_parser ("expr", p)
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-------------------------------------------------------------------
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-- parser method.
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-- In addition to the lexer, it takes an optional precedence:
|
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-- it won't read expressions whose precedence is lower or equal
|
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-- to [prec].
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-------------------------------------------------------------------
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function p :parse (lx, prec)
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prec = prec or 0
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------------------------------------------------------
|
||||
-- Extract the right parser and the corresponding
|
||||
-- options table, for (pre|in|suff)fix operators.
|
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-- Options include prec, assoc, transformers.
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------------------------------------------------------
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local function get_parser_info (tab)
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local p2 = tab :get (lx :is_keyword (lx :peek()))
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if p2 then -- keyword-based sequence found
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local function parser(lx) return raw_parse_sequence(lx, p2) end
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return parser, p2
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else -- Got to use the default parser
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local d = tab.default
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if d then return d.parse or d.parser, d
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else return false, false end
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||||
end
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||||
end
|
||||
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||||
------------------------------------------------------
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||||
-- Look for a prefix sequence. Multiple prefixes are
|
||||
-- handled through the recursive [p.parse] call.
|
||||
-- Notice the double-transform: one for the primary
|
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-- expr, and one for the one with the prefix op.
|
||||
------------------------------------------------------
|
||||
local function handle_prefix ()
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local fli = lx :lineinfo_right()
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local p2_func, p2 = get_parser_info (self.prefix)
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local op = p2_func and p2_func (lx)
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if op then -- Keyword-based sequence found
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local ili = lx :lineinfo_right() -- Intermediate LineInfo
|
||||
local e = p2.builder (op, self :parse (lx, p2.prec))
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||||
local lli = lx :lineinfo_left()
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return transform (transform (e, p2, ili, lli), self, fli, lli)
|
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else -- No prefix found, get a primary expression
|
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local e = self.primary(lx)
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local lli = lx :lineinfo_left()
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return transform (e, self, fli, lli)
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||||
end
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||||
end --</expr.parse.handle_prefix>
|
||||
|
||||
------------------------------------------------------
|
||||
-- Look for an infix sequence+right-hand-side operand.
|
||||
-- Return the whole binary expression result,
|
||||
-- or false if no operator was found.
|
||||
------------------------------------------------------
|
||||
local function handle_infix (e)
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||||
local p2_func, p2 = get_parser_info (self.infix)
|
||||
if not p2 then return false end
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||||
|
||||
-----------------------------------------
|
||||
-- Handle flattening operators: gather all operands
|
||||
-- of the series in [list]; when a different operator
|
||||
-- is found, stop, build from [list], [transform] and
|
||||
-- return.
|
||||
-----------------------------------------
|
||||
if (not p2.prec or p2.prec>prec) and p2.assoc=="flat" then
|
||||
local fli = lx:lineinfo_right()
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||||
local pflat, list = p2, { e }
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||||
repeat
|
||||
local op = p2_func(lx)
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||||
if not op then break end
|
||||
table.insert (list, self:parse (lx, p2.prec))
|
||||
local _ -- We only care about checking that p2==pflat
|
||||
_, p2 = get_parser_info (self.infix)
|
||||
until p2 ~= pflat
|
||||
local e2 = pflat.builder (list)
|
||||
local lli = lx:lineinfo_left()
|
||||
return transform (transform (e2, pflat, fli, lli), self, fli, lli)
|
||||
|
||||
-----------------------------------------
|
||||
-- Handle regular infix operators: [e] the LHS is known,
|
||||
-- just gather the operator and [e2] the RHS.
|
||||
-- Result goes in [e3].
|
||||
-----------------------------------------
|
||||
elseif p2.prec and p2.prec>prec or
|
||||
p2.prec==prec and p2.assoc=="right" then
|
||||
local fli = e.lineinfo.first -- lx:lineinfo_right()
|
||||
local op = p2_func(lx)
|
||||
if not op then return false end
|
||||
local e2 = self:parse (lx, p2.prec)
|
||||
local e3 = p2.builder (e, op, e2)
|
||||
local lli = lx:lineinfo_left()
|
||||
return transform (transform (e3, p2, fli, lli), self, fli, lli)
|
||||
|
||||
-----------------------------------------
|
||||
-- Check for non-associative operators, and complain if applicable.
|
||||
-----------------------------------------
|
||||
elseif p2.assoc=="none" and p2.prec==prec then
|
||||
M.parse_error (lx, "non-associative operator!")
|
||||
|
||||
-----------------------------------------
|
||||
-- No infix operator suitable at that precedence
|
||||
-----------------------------------------
|
||||
else return false end
|
||||
|
||||
end --</expr.parse.handle_infix>
|
||||
|
||||
------------------------------------------------------
|
||||
-- Look for a suffix sequence.
|
||||
-- Return the result of suffix operator on [e],
|
||||
-- or false if no operator was found.
|
||||
------------------------------------------------------
|
||||
local function handle_suffix (e)
|
||||
-- FIXME bad fli, must take e.lineinfo.first
|
||||
local p2_func, p2 = get_parser_info (self.suffix)
|
||||
if not p2 then return false end
|
||||
if not p2.prec or p2.prec>=prec then
|
||||
--local fli = lx:lineinfo_right()
|
||||
local fli = e.lineinfo.first
|
||||
local op = p2_func(lx)
|
||||
if not op then return false end
|
||||
local lli = lx:lineinfo_left()
|
||||
e = p2.builder (e, op)
|
||||
e = transform (transform (e, p2, fli, lli), self, fli, lli)
|
||||
return e
|
||||
end
|
||||
return false
|
||||
end --</expr.parse.handle_suffix>
|
||||
|
||||
------------------------------------------------------
|
||||
-- Parser body: read suffix and (infix+operand)
|
||||
-- extensions as long as we're able to fetch more at
|
||||
-- this precedence level.
|
||||
------------------------------------------------------
|
||||
local e = handle_prefix()
|
||||
repeat
|
||||
local x = handle_suffix (e); e = x or e
|
||||
local y = handle_infix (e); e = y or e
|
||||
until not (x or y)
|
||||
|
||||
-- No transform: it already happened in operators handling
|
||||
return e
|
||||
end --</expr.parse>
|
||||
|
||||
-------------------------------------------------------------------
|
||||
-- Construction
|
||||
-------------------------------------------------------------------
|
||||
if not p.primary then p.primary=p[1]; p[1]=nil end
|
||||
for _, t in ipairs{ "primary", "prefix", "infix", "suffix" } do
|
||||
if not p[t] then p[t] = { } end
|
||||
if not M.is_parser(p[t]) then M.multisequence(p[t]) end
|
||||
end
|
||||
function p:add(...) return self.primary:add(...) end
|
||||
return p
|
||||
end --</expr>
|
||||
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
--
|
||||
-- List parser generator
|
||||
--
|
||||
-------------------------------------------------------------------------------
|
||||
-- In [p], the following fields can be provided in input:
|
||||
--
|
||||
-- * [builder]: takes list of subparser results, returns AST
|
||||
-- * [transformers]: as usual
|
||||
-- * [name]: as usual
|
||||
--
|
||||
-- * [terminators]: list of strings representing the keywords which
|
||||
-- might mark the end of the list. When non-empty, the list is
|
||||
-- allowed to be empty. A string is treated as a single-element
|
||||
-- table, whose element is that string, e.g. ["do"] is the same as
|
||||
-- [{"do"}].
|
||||
--
|
||||
-- * [separators]: list of strings representing the keywords which can
|
||||
-- separate elements of the list. When non-empty, one of these
|
||||
-- keyword has to be found between each element. Lack of a separator
|
||||
-- indicates the end of the list. A string is treated as a
|
||||
-- single-element table, whose element is that string, e.g. ["do"]
|
||||
-- is the same as [{"do"}]. If [terminators] is empty/nil, then
|
||||
-- [separators] has to be non-empty.
|
||||
--
|
||||
-- After creation, the following fields are added:
|
||||
-- * [parse] the parsing function lexer->AST
|
||||
-- * [kind] == "list"
|
||||
--
|
||||
-------------------------------------------------------------------------------
|
||||
function M.list (p)
|
||||
M.make_parser ("list", p)
|
||||
|
||||
-------------------------------------------------------------------
|
||||
-- Parsing method
|
||||
-------------------------------------------------------------------
|
||||
function p :parse (lx)
|
||||
|
||||
------------------------------------------------------
|
||||
-- Used to quickly check whether there's a terminator
|
||||
-- or a separator immediately ahead
|
||||
------------------------------------------------------
|
||||
local function peek_is_in (keywords)
|
||||
return keywords and lx:is_keyword(lx:peek(), unpack(keywords)) end
|
||||
|
||||
local x = { }
|
||||
local fli = lx :lineinfo_right()
|
||||
|
||||
-- if there's a terminator to start with, don't bother trying
|
||||
local is_empty_list = self.terminators and (peek_is_in (self.terminators) or lx:peek().tag=="Eof")
|
||||
if not is_empty_list then
|
||||
repeat
|
||||
local item = self.primary(lx)
|
||||
table.insert (x, item) -- read one element
|
||||
until
|
||||
-- There's a separator list specified, and next token isn't in it.
|
||||
-- Otherwise, consume it with [lx:next()]
|
||||
self.separators and not(peek_is_in (self.separators) and lx:next()) or
|
||||
-- Terminator token ahead
|
||||
peek_is_in (self.terminators) or
|
||||
-- Last reason: end of file reached
|
||||
lx:peek().tag=="Eof"
|
||||
end
|
||||
|
||||
local lli = lx:lineinfo_left()
|
||||
|
||||
-- Apply the builder. It can be a string, or a callable value,
|
||||
-- or simply nothing.
|
||||
local b = self.builder
|
||||
if b then
|
||||
if type(b)=="string" then x.tag = b -- b is a string, use it as a tag
|
||||
elseif type(b)=="function" then x=b(x)
|
||||
else
|
||||
local bmt = getmetatable(b)
|
||||
if bmt and bmt.__call then x=b(x) end
|
||||
end
|
||||
end
|
||||
return transform (x, self, fli, lli)
|
||||
end --</list.parse>
|
||||
|
||||
-------------------------------------------------------------------
|
||||
-- Construction
|
||||
-------------------------------------------------------------------
|
||||
if not p.primary then p.primary = p[1]; p[1] = nil end
|
||||
if type(p.terminators) == "string" then p.terminators = { p.terminators }
|
||||
elseif p.terminators and #p.terminators == 0 then p.terminators = nil end
|
||||
if type(p.separators) == "string" then p.separators = { p.separators }
|
||||
elseif p.separators and #p.separators == 0 then p.separators = nil end
|
||||
|
||||
return p
|
||||
end --</list>
|
||||
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
--
|
||||
-- Keyword-conditioned parser generator
|
||||
--
|
||||
-------------------------------------------------------------------------------
|
||||
--
|
||||
-- Only apply a parser if a given keyword is found. The result of
|
||||
-- [gg.onkeyword] parser is the result of the subparser (modulo
|
||||
-- [transformers] applications).
|
||||
--
|
||||
-- lineinfo: the keyword is *not* included in the boundaries of the
|
||||
-- resulting lineinfo. A review of all usages of gg.onkeyword() in the
|
||||
-- implementation of metalua has shown that it was the appropriate choice
|
||||
-- in every case.
|
||||
--
|
||||
-- Input fields:
|
||||
--
|
||||
-- * [name]: as usual
|
||||
--
|
||||
-- * [transformers]: as usual
|
||||
--
|
||||
-- * [peek]: if non-nil, the conditioning keyword is left in the lexeme
|
||||
-- stream instead of being consumed.
|
||||
--
|
||||
-- * [primary]: the subparser.
|
||||
--
|
||||
-- * [keywords]: list of strings representing triggering keywords.
|
||||
--
|
||||
-- * Table-part entries can contain strings, and/or exactly one parser.
|
||||
-- Strings are put in [keywords], and the parser is put in [primary].
|
||||
--
|
||||
-- After the call, the following fields will be set:
|
||||
--
|
||||
-- * [parse] the parsing method
|
||||
-- * [kind] == "onkeyword"
|
||||
-- * [primary]
|
||||
-- * [keywords]
|
||||
--
|
||||
-------------------------------------------------------------------------------
|
||||
function M.onkeyword (p)
|
||||
M.make_parser ("onkeyword", p)
|
||||
|
||||
-------------------------------------------------------------------
|
||||
-- Parsing method
|
||||
-------------------------------------------------------------------
|
||||
function p :parse (lx)
|
||||
if lx :is_keyword (lx:peek(), unpack(self.keywords)) then
|
||||
local fli = lx:lineinfo_right()
|
||||
if not self.peek then lx:next() end
|
||||
local content = self.primary (lx)
|
||||
local lli = lx:lineinfo_left()
|
||||
local li = content.lineinfo or { }
|
||||
fli, lli = li.first or fli, li.last or lli
|
||||
return transform (content, p, fli, lli)
|
||||
else return false end
|
||||
end
|
||||
|
||||
-------------------------------------------------------------------
|
||||
-- Construction
|
||||
-------------------------------------------------------------------
|
||||
if not p.keywords then p.keywords = { } end
|
||||
for _, x in ipairs(p) do
|
||||
if type(x)=="string" then table.insert (p.keywords, x)
|
||||
else assert (not p.primary and M.is_parser (x)); p.primary = x end
|
||||
end
|
||||
assert (next (p.keywords), "Missing trigger keyword in gg.onkeyword")
|
||||
assert (p.primary, 'no primary parser in gg.onkeyword')
|
||||
return p
|
||||
end --</onkeyword>
|
||||
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
--
|
||||
-- Optional keyword consummer pseudo-parser generator
|
||||
--
|
||||
-------------------------------------------------------------------------------
|
||||
--
|
||||
-- This doesn't return a real parser, just a function. That function parses
|
||||
-- one of the keywords passed as parameters, and returns it. It returns
|
||||
-- [false] if no matching keyword is found.
|
||||
--
|
||||
-- Notice that tokens returned by lexer already carry lineinfo, therefore
|
||||
-- there's no need to add them, as done usually through transform() calls.
|
||||
-------------------------------------------------------------------------------
|
||||
function M.optkeyword (...)
|
||||
local args = {...}
|
||||
if type (args[1]) == "table" then
|
||||
assert (#args == 1)
|
||||
args = args[1]
|
||||
end
|
||||
for _, v in ipairs(args) do assert (type(v)=="string") end
|
||||
return function (lx)
|
||||
local x = lx:is_keyword (lx:peek(), unpack (args))
|
||||
if x then lx:next(); return x
|
||||
else return false end
|
||||
end
|
||||
end
|
||||
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
--
|
||||
-- Run a parser with a special lexer
|
||||
--
|
||||
-------------------------------------------------------------------------------
|
||||
--
|
||||
-- This doesn't return a real parser, just a function.
|
||||
-- First argument is the lexer class to be used with the parser,
|
||||
-- 2nd is the parser itself.
|
||||
-- The resulting parser returns whatever the argument parser does.
|
||||
--
|
||||
-------------------------------------------------------------------------------
|
||||
function M.with_lexer(new_lexer, parser)
|
||||
|
||||
-------------------------------------------------------------------
|
||||
-- Most gg functions take their parameters in a table, so it's
|
||||
-- better to silently accept when with_lexer{ } is called with
|
||||
-- its arguments in a list:
|
||||
-------------------------------------------------------------------
|
||||
if not parser and #new_lexer==2 and type(new_lexer[1])=='table' then
|
||||
return M.with_lexer(unpack(new_lexer))
|
||||
end
|
||||
|
||||
-------------------------------------------------------------------
|
||||
-- Save the current lexer, switch it for the new one, run the parser,
|
||||
-- restore the previous lexer, even if the parser caused an error.
|
||||
-------------------------------------------------------------------
|
||||
return function (lx)
|
||||
local old_lexer = getmetatable(lx)
|
||||
lx:sync()
|
||||
setmetatable(lx, new_lexer)
|
||||
local status, result = pcall(parser, lx)
|
||||
lx:sync()
|
||||
setmetatable(lx, old_lexer)
|
||||
if status then return result else error(result) end
|
||||
end
|
||||
end
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
--
|
||||
-- Make sure a parser is used and returns successfully.
|
||||
--
|
||||
--------------------------------------------------------------------------------
|
||||
function M.nonempty(primary)
|
||||
local p = M.make_parser('non-empty list', { primary = primary, name=primary.name })
|
||||
function p :parse (lx)
|
||||
local fli = lx:lineinfo_right()
|
||||
local content = self.primary (lx)
|
||||
local lli = lx:lineinfo_left()
|
||||
local li = content.lineinfo or { }
|
||||
fli, lli = li.first or fli, li.last or lli
|
||||
if #content == 0 then
|
||||
M.parse_error (lx, "`%s' must not be empty.", self.name or "list")
|
||||
else
|
||||
return transform (content, self, fli, lli)
|
||||
end
|
||||
end
|
||||
return p
|
||||
end
|
||||
|
||||
local FUTURE_MT = { }
|
||||
function FUTURE_MT:__tostring() return "<Proxy parser module>" end
|
||||
function FUTURE_MT:__newindex(key, value) error "don't write in futures" end
|
||||
function FUTURE_MT :__index (parser_name)
|
||||
return function(...)
|
||||
local p, m = rawget(self, '__path'), self.__module
|
||||
if p then for _, name in ipairs(p) do
|
||||
m=rawget(m, name)
|
||||
if not m then error ("Submodule '"..name.."' undefined") end
|
||||
end end
|
||||
local f = rawget(m, parser_name)
|
||||
if not f then error ("Parser '"..parser_name.."' undefined") end
|
||||
return f(...)
|
||||
end
|
||||
end
|
||||
|
||||
function M.future(module, ...)
|
||||
checks('table')
|
||||
local path = ... and {...}
|
||||
if path then for _, x in ipairs(path) do
|
||||
assert(type(x)=='string', "Bad future arg")
|
||||
end end
|
||||
local self = { __module = module,
|
||||
__path = path }
|
||||
return setmetatable(self, FUTURE_MT)
|
||||
end
|
||||
|
||||
return M
|
||||
@ -0,0 +1,678 @@
|
||||
-------------------------------------------------------------------------------
|
||||
-- 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
|
||||
--
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
require 'checks'
|
||||
|
||||
local M = { }
|
||||
|
||||
local lexer = { alpha={ }, sym={ } }
|
||||
lexer.__index=lexer
|
||||
lexer.__type='lexer.stream'
|
||||
|
||||
M.lexer = lexer
|
||||
|
||||
|
||||
local debugf = function() end
|
||||
-- local debugf=printf
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Some locale settings produce bad results, e.g. French locale
|
||||
-- expect float numbers to use commas instead of periods.
|
||||
-- TODO: change number parser into something loclae-independent,
|
||||
-- locales are nasty.
|
||||
----------------------------------------------------------------------
|
||||
os.setlocale('C')
|
||||
|
||||
local MT = { }
|
||||
|
||||
M.metatables=MT
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Create a new metatable, for a new class of objects.
|
||||
----------------------------------------------------------------------
|
||||
local function new_metatable(name)
|
||||
local mt = { __type = 'lexer.'..name };
|
||||
mt.__index = mt
|
||||
MT[name] = mt
|
||||
end
|
||||
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Position: represent a point in a source file.
|
||||
----------------------------------------------------------------------
|
||||
new_metatable 'position'
|
||||
|
||||
local position_idx=1
|
||||
|
||||
function M.new_position(line, column, offset, source)
|
||||
checks('number', 'number', 'number', 'string')
|
||||
local id = position_idx; position_idx = position_idx+1
|
||||
return setmetatable({line=line, column=column, offset=offset,
|
||||
source=source, id=id}, MT.position)
|
||||
end
|
||||
|
||||
function MT.position :__tostring()
|
||||
return string.format("<%s%s|L%d|C%d|K%d>",
|
||||
self.comments and "C|" or "",
|
||||
self.source, self.line, self.column, self.offset)
|
||||
end
|
||||
|
||||
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Position factory: convert offsets into line/column/offset positions.
|
||||
----------------------------------------------------------------------
|
||||
new_metatable 'position_factory'
|
||||
|
||||
function M.new_position_factory(src, src_name)
|
||||
-- assert(type(src)=='string')
|
||||
-- assert(type(src_name)=='string')
|
||||
local lines = { 1 }
|
||||
for offset in src :gmatch '\n()' do table.insert(lines, offset) end
|
||||
local max = #src+1
|
||||
table.insert(lines, max+1) -- +1 includes Eof
|
||||
return setmetatable({ src_name=src_name, line2offset=lines, max=max },
|
||||
MT.position_factory)
|
||||
end
|
||||
|
||||
function MT.position_factory :get_position (offset)
|
||||
-- assert(type(offset)=='number')
|
||||
assert(offset<=self.max)
|
||||
local line2offset = self.line2offset
|
||||
local left = self.last_left or 1
|
||||
if offset<line2offset[left] then left=1 end
|
||||
local right = left+1
|
||||
if line2offset[right]<=offset then right = right+1 end
|
||||
if line2offset[right]<=offset then right = #line2offset end
|
||||
while true do
|
||||
-- print (" trying lines "..left.."/"..right..", offsets "..line2offset[left]..
|
||||
-- "/"..line2offset[right].." for offset "..offset)
|
||||
-- assert(line2offset[left]<=offset)
|
||||
-- assert(offset<line2offset[right])
|
||||
-- assert(left<right)
|
||||
if left+1==right then break end
|
||||
local middle = math.floor((left+right)/2)
|
||||
if line2offset[middle]<=offset then left=middle else right=middle end
|
||||
end
|
||||
-- assert(left+1==right)
|
||||
-- printf("found that offset %d is between %d and %d, hence on line %d",
|
||||
-- offset, line2offset[left], line2offset[right], left)
|
||||
local line = left
|
||||
local column = offset - line2offset[line] + 1
|
||||
self.last_left = left
|
||||
return M.new_position(line, column, offset, self.src_name)
|
||||
end
|
||||
|
||||
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Lineinfo: represent a node's range in a source file;
|
||||
-- embed information about prefix and suffix comments.
|
||||
----------------------------------------------------------------------
|
||||
new_metatable 'lineinfo'
|
||||
|
||||
function M.new_lineinfo(first, last)
|
||||
checks('lexer.position', 'lexer.position')
|
||||
return setmetatable({first=first, last=last}, MT.lineinfo)
|
||||
end
|
||||
|
||||
function MT.lineinfo :__tostring()
|
||||
local fli, lli = self.first, self.last
|
||||
local line = fli.line; if line~=lli.line then line =line ..'-'..lli.line end
|
||||
local column = fli.column; if column~=lli.column then column=column..'-'..lli.column end
|
||||
local offset = fli.offset; if offset~=lli.offset then offset=offset..'-'..lli.offset end
|
||||
return string.format("<%s%s|L%s|C%s|K%s%s>",
|
||||
fli.comments and "C|" or "",
|
||||
fli.source, line, column, offset,
|
||||
lli.comments and "|C" or "")
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Token: atomic Lua language element, with a category, a content,
|
||||
-- and some lineinfo relating it to its original source.
|
||||
----------------------------------------------------------------------
|
||||
new_metatable 'token'
|
||||
|
||||
function M.new_token(tag, content, lineinfo)
|
||||
--printf("TOKEN `%s{ %q, lineinfo = %s} boundaries %d, %d",
|
||||
-- tag, content, tostring(lineinfo), lineinfo.first.id, lineinfo.last.id)
|
||||
return setmetatable({tag=tag, lineinfo=lineinfo, content}, MT.token)
|
||||
end
|
||||
|
||||
function MT.token :__tostring()
|
||||
--return string.format("`%s{ %q, %s }", self.tag, self[1], tostring(self.lineinfo))
|
||||
return string.format("`%s %q", self.tag, self[1])
|
||||
end
|
||||
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Comment: series of comment blocks with associated lineinfo.
|
||||
-- To be attached to the tokens just before and just after them.
|
||||
----------------------------------------------------------------------
|
||||
new_metatable 'comment'
|
||||
|
||||
function M.new_comment(lines)
|
||||
local first = lines[1].lineinfo.first
|
||||
local last = lines[#lines].lineinfo.last
|
||||
local lineinfo = M.new_lineinfo(first, last)
|
||||
return setmetatable({lineinfo=lineinfo, unpack(lines)}, MT.comment)
|
||||
end
|
||||
|
||||
function MT.comment :text()
|
||||
local last_line = self[1].lineinfo.last.line
|
||||
local acc = { }
|
||||
for i, line in ipairs(self) do
|
||||
local nreturns = line.lineinfo.first.line - last_line
|
||||
table.insert(acc, ("\n"):rep(nreturns))
|
||||
table.insert(acc, line[1])
|
||||
end
|
||||
return table.concat(acc)
|
||||
end
|
||||
|
||||
function M.new_comment_line(text, lineinfo, nequals)
|
||||
checks('string', 'lexer.lineinfo', '?number')
|
||||
return { lineinfo = lineinfo, text, nequals }
|
||||
end
|
||||
|
||||
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Patterns used by [lexer :extract] to decompose the raw string into
|
||||
-- correctly tagged tokens.
|
||||
----------------------------------------------------------------------
|
||||
lexer.patterns = {
|
||||
spaces = "^[ \r\n\t]*()",
|
||||
short_comment = "^%-%-([^\n]*)\n?()",
|
||||
--final_short_comment = "^%-%-([^\n]*)()$",
|
||||
long_comment = "^%-%-%[(=*)%[\n?(.-)%]%1%]()",
|
||||
long_string = "^%[(=*)%[\n?(.-)%]%1%]()",
|
||||
number_longint = "^%d+[uU]?[lL][lL]()",
|
||||
number_longint_hex = "^%x+[uU]?[lL][lL]()",
|
||||
number_mantissa = { "^%d+%.?%d*()", "^%d*%.%d+()" },
|
||||
number_mantissa_hex = { "^%x+%.?%x*()", "^%x*%.%x+()" }, --Lua5.1 and Lua5.2
|
||||
number_exponent = "^[eE][%+%-]?%d+()",
|
||||
number_exponent_hex = "^[pP][%+%-]?%d+()", --Lua5.2
|
||||
number_hex = "^0[xX]()",
|
||||
number_imaginary = "^[iI]()",
|
||||
word = "^([%a_][%w_]*)()",
|
||||
}
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- unescape a whole string, applying [unesc_digits] and
|
||||
-- [unesc_letter] as many times as required.
|
||||
----------------------------------------------------------------------
|
||||
local function unescape_string (s)
|
||||
|
||||
-- Turn the digits of an escape sequence into the corresponding
|
||||
-- character, e.g. [unesc_digits("123") == string.char(123)].
|
||||
local function unesc_digits (backslashes, digits)
|
||||
if #backslashes%2==0 then
|
||||
-- Even number of backslashes, they escape each other, not the digits.
|
||||
-- Return them so that unesc_letter() can treat them
|
||||
return backslashes..digits
|
||||
else
|
||||
-- Remove the odd backslash, which escapes the number sequence.
|
||||
-- The rest will be returned and parsed by unesc_letter()
|
||||
backslashes = backslashes :sub (1,-2)
|
||||
end
|
||||
local k, j, i = digits :reverse() :byte(1, 3)
|
||||
local z = string.byte "0"
|
||||
local code = (k or z) + 10*(j or z) + 100*(i or z) - 111*z
|
||||
if code > 255 then
|
||||
error ("Illegal escape sequence '\\"..digits..
|
||||
"' in string: ASCII codes must be in [0..255]")
|
||||
end
|
||||
local c = string.char (code)
|
||||
if c == '\\' then c = '\\\\' end -- parsed by unesc_letter (test: "\092b" --> "\\b")
|
||||
return backslashes..c
|
||||
end
|
||||
|
||||
-- Turn hex digits of escape sequence into char.
|
||||
local function unesc_hex(backslashes, digits)
|
||||
if #backslashes%2==0 then
|
||||
return backslashes..'x'..digits
|
||||
else
|
||||
backslashes = backslashes :sub (1,-2)
|
||||
end
|
||||
local c = string.char(tonumber(digits,16))
|
||||
if c == '\\' then c = '\\\\' end -- parsed by unesc_letter (test: "\x5cb" --> "\\b")
|
||||
return backslashes..c
|
||||
end
|
||||
|
||||
-- Handle Lua 5.2 \z sequences
|
||||
local function unesc_z(backslashes, more)
|
||||
if #backslashes%2==0 then
|
||||
return backslashes..more
|
||||
else
|
||||
return backslashes :sub (1,-2)
|
||||
end
|
||||
end
|
||||
|
||||
-- Take a letter [x], and returns the character represented by the
|
||||
-- sequence ['\\'..x], e.g. [unesc_letter "n" == "\n"].
|
||||
local function unesc_letter(x)
|
||||
local t = {
|
||||
a = "\a", b = "\b", f = "\f",
|
||||
n = "\n", r = "\r", t = "\t", v = "\v",
|
||||
["\\"] = "\\", ["'"] = "'", ['"'] = '"', ["\n"] = "\n" }
|
||||
return t[x] or x
|
||||
end
|
||||
|
||||
s = s: gsub ("(\\+)(z%s*)", unesc_z) -- Lua 5.2
|
||||
s = s: gsub ("(\\+)([0-9][0-9]?[0-9]?)", unesc_digits)
|
||||
s = s: gsub ("(\\+)x([0-9a-fA-F][0-9a-fA-F])", unesc_hex) -- Lua 5.2
|
||||
s = s: gsub ("\\(%D)",unesc_letter)
|
||||
return s
|
||||
end
|
||||
|
||||
lexer.extractors = {
|
||||
"extract_long_comment", "extract_short_comment",
|
||||
"extract_short_string", "extract_word", "extract_number",
|
||||
"extract_long_string", "extract_symbol" }
|
||||
|
||||
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Really extract next token from the raw string
|
||||
-- (and update the index).
|
||||
-- loc: offset of the position just after spaces and comments
|
||||
-- previous_i: offset in src before extraction began
|
||||
----------------------------------------------------------------------
|
||||
function lexer :extract ()
|
||||
local attached_comments = { }
|
||||
local function gen_token(...)
|
||||
local token = M.new_token(...)
|
||||
if #attached_comments>0 then -- attach previous comments to token
|
||||
local comments = M.new_comment(attached_comments)
|
||||
token.lineinfo.first.comments = comments
|
||||
if self.lineinfo_last_extracted then
|
||||
self.lineinfo_last_extracted.comments = comments
|
||||
end
|
||||
attached_comments = { }
|
||||
end
|
||||
token.lineinfo.first.facing = self.lineinfo_last_extracted
|
||||
self.lineinfo_last_extracted.facing = assert(token.lineinfo.first)
|
||||
self.lineinfo_last_extracted = assert(token.lineinfo.last)
|
||||
return token
|
||||
end
|
||||
while true do -- loop until a non-comment token is found
|
||||
|
||||
-- skip whitespaces
|
||||
self.i = self.src:match (self.patterns.spaces, self.i)
|
||||
if self.i>#self.src then
|
||||
local fli = self.posfact :get_position (#self.src+1)
|
||||
local lli = self.posfact :get_position (#self.src+1) -- ok?
|
||||
local tok = gen_token("Eof", "eof", M.new_lineinfo(fli, lli))
|
||||
tok.lineinfo.last.facing = lli
|
||||
return tok
|
||||
end
|
||||
local i_first = self.i -- loc = position after whitespaces
|
||||
|
||||
-- try every extractor until a token is found
|
||||
for _, extractor in ipairs(self.extractors) do
|
||||
local tag, content, xtra = self [extractor] (self)
|
||||
if tag then
|
||||
local fli = self.posfact :get_position (i_first)
|
||||
local lli = self.posfact :get_position (self.i-1)
|
||||
local lineinfo = M.new_lineinfo(fli, lli)
|
||||
if tag=='Comment' then
|
||||
local prev_comment = attached_comments[#attached_comments]
|
||||
if not xtra -- new comment is short
|
||||
and prev_comment and not prev_comment[2] -- prev comment is short
|
||||
and prev_comment.lineinfo.last.line+1==fli.line then -- adjascent lines
|
||||
-- concat with previous comment
|
||||
prev_comment[1] = prev_comment[1].."\n"..content -- TODO quadratic, BAD!
|
||||
prev_comment.lineinfo.last = lli
|
||||
else -- accumulate comment
|
||||
local comment = M.new_comment_line(content, lineinfo, xtra)
|
||||
table.insert(attached_comments, comment)
|
||||
end
|
||||
break -- back to skipping spaces
|
||||
else -- not a comment: real token, then
|
||||
return gen_token(tag, content, lineinfo)
|
||||
end -- if token is a comment
|
||||
end -- if token found
|
||||
end -- for each extractor
|
||||
end -- while token is a comment
|
||||
end -- :extract()
|
||||
|
||||
|
||||
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Extract a short comment.
|
||||
----------------------------------------------------------------------
|
||||
function lexer :extract_short_comment()
|
||||
-- TODO: handle final_short_comment
|
||||
local content, j = self.src :match (self.patterns.short_comment, self.i)
|
||||
if content then self.i=j; return 'Comment', content, nil end
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Extract a long comment.
|
||||
----------------------------------------------------------------------
|
||||
function lexer :extract_long_comment()
|
||||
local equals, content, j = self.src:match (self.patterns.long_comment, self.i)
|
||||
if j then self.i = j; return "Comment", content, #equals end
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Extract a '...' or "..." short string.
|
||||
----------------------------------------------------------------------
|
||||
function lexer :extract_short_string()
|
||||
local k = self.src :sub (self.i,self.i) -- first char
|
||||
if k~=[[']] and k~=[["]] then return end -- no match'
|
||||
local i = self.i + 1
|
||||
local j = i
|
||||
while true do
|
||||
local x,y; x, j, y = self.src :match ("([\\\r\n"..k.."])()(.?)", j) -- next interesting char
|
||||
if x == '\\' then
|
||||
if y == 'z' then -- Lua 5.2 \z
|
||||
j = self.src :match ("^%s*()", j+1)
|
||||
else
|
||||
j=j+1 -- escaped char
|
||||
end
|
||||
elseif x == k then break -- end of string
|
||||
else
|
||||
assert (not x or x=='\r' or x=='\n')
|
||||
return nil, 'Unterminated string'
|
||||
end
|
||||
end
|
||||
self.i = j
|
||||
|
||||
return 'String', unescape_string (self.src :sub (i,j-2))
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Extract Id or Keyword.
|
||||
----------------------------------------------------------------------
|
||||
function lexer :extract_word()
|
||||
local word, j = self.src:match (self.patterns.word, self.i)
|
||||
if word then
|
||||
self.i = j
|
||||
return (self.alpha [word] and 'Keyword' or 'Id'), word
|
||||
end
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Extract Number.
|
||||
----------------------------------------------------------------------
|
||||
function lexer :extract_number()
|
||||
local patt = self.patterns
|
||||
local s = self.src
|
||||
local j = s:match(patt.number_hex, self.i)
|
||||
local hex = j ~= nil
|
||||
local longint = hex and patt.number_longint_hex or patt.number_longint
|
||||
local mantissa1 = hex and patt.number_mantissa_hex[1] or patt.number_mantissa[1]
|
||||
local mantissa2 = hex and patt.number_mantissa_hex[2] or patt.number_mantissa[2]
|
||||
local exponent = hex and patt.number_exponent_hex or patt.number_exponent
|
||||
if not hex then j = self.i end
|
||||
|
||||
local t = s:match(longint, j)
|
||||
if t then
|
||||
j = t
|
||||
else
|
||||
j = s:match(mantissa1, j) or s:match(mantissa2, j)
|
||||
if not j then return end
|
||||
j = s:match(exponent, j) or j
|
||||
j = s:match(patt.number_imaginary, j) or j
|
||||
end
|
||||
|
||||
local str = self.src:sub (self.i, j-1)
|
||||
self.i = j
|
||||
-- Number found, interpret with tonumber() and return it
|
||||
-- return str as the fallback when processing formats not supported by the current interpreter
|
||||
return 'Number', (tonumber (str) or str)
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Extract long string.
|
||||
----------------------------------------------------------------------
|
||||
function lexer :extract_long_string()
|
||||
local _, content, j = self.src :match (self.patterns.long_string, self.i)
|
||||
if j then self.i = j; return 'String', content end
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Extract symbol.
|
||||
----------------------------------------------------------------------
|
||||
function lexer :extract_symbol()
|
||||
local k = self.src:sub (self.i,self.i)
|
||||
local symk = self.sym [k] -- symbols starting with `k`
|
||||
if not symk then
|
||||
self.i = self.i + 1
|
||||
return 'Keyword', k
|
||||
end
|
||||
for _, sym in pairs (symk) do
|
||||
if sym == self.src:sub (self.i, self.i + #sym - 1) then
|
||||
self.i = self.i + #sym
|
||||
return 'Keyword', sym
|
||||
end
|
||||
end
|
||||
self.i = self.i+1
|
||||
return 'Keyword', k
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Add a keyword to the list of keywords recognized by the lexer.
|
||||
----------------------------------------------------------------------
|
||||
function lexer :add (w, ...)
|
||||
assert(not ..., "lexer :add() takes only one arg, although possibly a table")
|
||||
if type (w) == "table" then
|
||||
for _, x in ipairs (w) do self :add (x) end
|
||||
else
|
||||
if w:match (self.patterns.word .. "$") then self.alpha [w] = true
|
||||
elseif w:match "^%p%p+$" then
|
||||
local k = w:sub(1,1)
|
||||
local list = self.sym [k]
|
||||
if not list then list = { }; self.sym [k] = list end
|
||||
table.insert (list, w)
|
||||
elseif w:match "^%p$" then return
|
||||
else error "Invalid keyword" end
|
||||
end
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Return the [n]th next token, without consuming it.
|
||||
-- [n] defaults to 1. If it goes pass the end of the stream, an EOF
|
||||
-- token is returned.
|
||||
----------------------------------------------------------------------
|
||||
function lexer :peek (n)
|
||||
if not n then n=1 end
|
||||
if n > #self.peeked then
|
||||
for i = #self.peeked+1, n do
|
||||
self.peeked [i] = self :extract()
|
||||
end
|
||||
end
|
||||
return self.peeked [n]
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Return the [n]th next token, removing it as well as the 0..n-1
|
||||
-- previous tokens. [n] defaults to 1. If it goes pass the end of the
|
||||
-- stream, an EOF token is returned.
|
||||
----------------------------------------------------------------------
|
||||
function lexer :next (n)
|
||||
n = n or 1
|
||||
self :peek (n)
|
||||
local a
|
||||
for i=1,n do
|
||||
a = table.remove (self.peeked, 1)
|
||||
-- TODO: is this used anywhere? I think not. a.lineinfo.last may be nil.
|
||||
--self.lastline = a.lineinfo.last.line
|
||||
end
|
||||
self.lineinfo_last_consumed = a.lineinfo.last
|
||||
return a
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Returns an object which saves the stream's current state.
|
||||
----------------------------------------------------------------------
|
||||
-- FIXME there are more fields than that to save
|
||||
function lexer :save () return { self.i; {unpack(self.peeked) } } end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Restore the stream's state, as saved by method [save].
|
||||
----------------------------------------------------------------------
|
||||
-- FIXME there are more fields than that to restore
|
||||
function lexer :restore (s) self.i=s[1]; self.peeked=s[2] end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Resynchronize: cancel any token in self.peeked, by emptying the
|
||||
-- list and resetting the indexes
|
||||
----------------------------------------------------------------------
|
||||
function lexer :sync()
|
||||
local p1 = self.peeked[1]
|
||||
if p1 then
|
||||
local li_first = p1.lineinfo.first
|
||||
if li_first.comments then li_first=li_first.comments.lineinfo.first end
|
||||
self.i = li_first.offset
|
||||
self.column_offset = self.i - li_first.column
|
||||
self.peeked = { }
|
||||
self.attached_comments = p1.lineinfo.first.comments or { }
|
||||
end
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Take the source and offset of an old lexer.
|
||||
----------------------------------------------------------------------
|
||||
function lexer :takeover(old)
|
||||
self :sync(); old :sync()
|
||||
for _, field in ipairs{ 'i', 'src', 'attached_comments', 'posfact' } do
|
||||
self[field] = old[field]
|
||||
end
|
||||
return self
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Return the current position in the sources. This position is between
|
||||
-- two tokens, and can be within a space / comment area, and therefore
|
||||
-- have a non-null width. :lineinfo_left() returns the beginning of the
|
||||
-- separation area, :lineinfo_right() returns the end of that area.
|
||||
--
|
||||
-- ____ last consummed token ____ first unconsummed token
|
||||
-- / /
|
||||
-- XXXXX <spaces and comments> YYYYY
|
||||
-- \____ \____
|
||||
-- :lineinfo_left() :lineinfo_right()
|
||||
----------------------------------------------------------------------
|
||||
function lexer :lineinfo_right()
|
||||
return self :peek(1).lineinfo.first
|
||||
end
|
||||
|
||||
function lexer :lineinfo_left()
|
||||
return self.lineinfo_last_consumed
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Create a new lexstream.
|
||||
----------------------------------------------------------------------
|
||||
function lexer :newstream (src_or_stream, name)
|
||||
name = name or "?"
|
||||
if type(src_or_stream)=='table' then -- it's a stream
|
||||
return setmetatable ({ }, self) :takeover (src_or_stream)
|
||||
elseif type(src_or_stream)=='string' then -- it's a source string
|
||||
local src = src_or_stream
|
||||
local pos1 = M.new_position(1, 1, 1, name)
|
||||
local stream = {
|
||||
src_name = name; -- Name of the file
|
||||
src = src; -- The source, as a single string
|
||||
peeked = { }; -- Already peeked, but not discarded yet, tokens
|
||||
i = 1; -- Character offset in src
|
||||
attached_comments = { },-- comments accumulator
|
||||
lineinfo_last_extracted = pos1,
|
||||
lineinfo_last_consumed = pos1,
|
||||
posfact = M.new_position_factory (src_or_stream, name)
|
||||
}
|
||||
setmetatable (stream, self)
|
||||
|
||||
-- Skip initial sharp-bang for Unix scripts
|
||||
-- FIXME: redundant with mlp.chunk()
|
||||
if src and src :match "^#!" then
|
||||
local endofline = src :find "\n"
|
||||
stream.i = endofline and (endofline + 1) or #src
|
||||
end
|
||||
return stream
|
||||
else
|
||||
assert(false, ":newstream() takes a source string or a stream, not a "..
|
||||
type(src_or_stream))
|
||||
end
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- If there's no ... args, return the token a (whose truth value is
|
||||
-- true) if it's a `Keyword{ }, or nil. If there are ... args, they
|
||||
-- have to be strings. if the token a is a keyword, and it's content
|
||||
-- is one of the ... args, then returns it (it's truth value is
|
||||
-- true). If no a keyword or not in ..., return nil.
|
||||
----------------------------------------------------------------------
|
||||
function lexer :is_keyword (a, ...)
|
||||
if not a or a.tag ~= "Keyword" then return false end
|
||||
local words = {...}
|
||||
if #words == 0 then return a[1] end
|
||||
for _, w in ipairs (words) do
|
||||
if w == a[1] then return w end
|
||||
end
|
||||
return false
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Cause an error if the next token isn't a keyword whose content
|
||||
-- is listed among ... args (which have to be strings).
|
||||
----------------------------------------------------------------------
|
||||
function lexer :check (...)
|
||||
local words = {...}
|
||||
local a = self :next()
|
||||
local function err ()
|
||||
error ("Got " .. tostring (a) ..
|
||||
", expected one of these keywords : '" ..
|
||||
table.concat (words,"', '") .. "'") end
|
||||
if not a or a.tag ~= "Keyword" then err () end
|
||||
if #words == 0 then return a[1] end
|
||||
for _, w in ipairs (words) do
|
||||
if w == a[1] then return w end
|
||||
end
|
||||
err ()
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
--
|
||||
----------------------------------------------------------------------
|
||||
function lexer :clone()
|
||||
local alpha_clone, sym_clone = { }, { }
|
||||
for word in pairs(self.alpha) do alpha_clone[word]=true end
|
||||
for letter, list in pairs(self.sym) do sym_clone[letter] = { unpack(list) } end
|
||||
local clone = { alpha=alpha_clone, sym=sym_clone }
|
||||
setmetatable(clone, self)
|
||||
clone.__index = clone
|
||||
return clone
|
||||
end
|
||||
|
||||
----------------------------------------------------------------------
|
||||
-- Cancel everything left in a lexer, all subsequent attempts at
|
||||
-- `:peek()` or `:next()` will return `Eof`.
|
||||
----------------------------------------------------------------------
|
||||
function lexer :kill()
|
||||
self.i = #self.src+1
|
||||
self.peeked = { }
|
||||
self.attached_comments = { }
|
||||
self.lineinfo_last = self.posfact :get_position (#self.src+1)
|
||||
end
|
||||
|
||||
return M
|
||||
Reference in New Issue
Block a user