Split "DSL" definition from the "all-in-parser-and-output"

7 files changed, 210 insertions, 127 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..28eceec
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,6 @@
+all: test
+
+test:
+	busted
+
+.PHONY: all test
diff --git a/db/c.lua b/db/c.lua
index adc6bd7..c2d10e5 100644
--- a/db/c.lua
+++ b/db/c.lua
@@ -1,3 +1,4 @@
+scheme "headers/1"
 aliases "ISO/IEC 9899:1990" {"ANSI X3.159-1989", "C89", "C90", "ANSI C"}
 aliases "ISO/IEC 9899:1990/Amd 1:1995" {"C95"}
 aliases "ISO/IEC 9899:1999" {"C99"}
diff --git a/db/posix.lua b/db/posix.lua
index 3757a7d..467294c 100644
--- a/db/posix.lua
+++ b/db/posix.lua
@@ -1,3 +1,4 @@
+scheme "headers/1"
 aliases "IEEE Std 1003.1-2008" {"POSIX"}
 headers "POSIX" {
 	"aio.h",
diff --git a/headers.lua b/headers.lua
index 13d98a9..972b360 100755
--- a/headers.lua
+++ b/headers.lua
@@ -1,130 +1,17 @@
 #!/usr/bin/env lua
---- For example:
----
----     $ ./headers.lua db/c.lua C23
----     assert.h
----     ctype.h
----     ...
-local public = {}
-local private = {}
-private.tags = {}
-private.tags_lookup = {}
-private.headers = {}
-
-
-local tag do
-	local methods = {}
-	function methods:add (header)
-		table.insert(self.headers_, header)
-	end
-	local function headers (self)
-		local result = {}
-		for _, value in pairs(self.headers_) do
-			if type(value) == "function" then
-				value(result)
-			else
-				table.insert(result, value)
-			end
-		end
-		return result
-	end
-	local mt = {
-		__tostring=function (self) return self.name end,
-		__index=function (self, key)
-			if key == "headers" then
-				return headers(self)
-			end
-			return methods[key]
-		end,
-	}
-	function tag (name)
-		return setmetatable({name=name, headers_={}}, mt)
-	end
-end
-
-
-local alias do
-	local mt = {
-		__tostring = function (self) return string.format("%s (%s)", self.name, tostring(self.tag)) end,
-		__index = function (self, key) return self.tag[key] end,
-	}
-	function alias (name, tag)
-		return setmetatable({name=name, tag=tag}, mt)
-	end
-end
-
-
-local function include (source)
-	return function (target)
-		for _, header in pairs(source.headers) do
-			table.insert(target, header)
-		end
-	end
-end
-
-
-local function remove (header)
-	return function (target)
-		for key, value in pairs(target) do
-			if value == header then
-				table.remove(target, key)
-			end
-		end
-	end
-end
-
-
-local function get_or_create_tag (name)
-	local found = private.tags_lookup[name]
-	if not found then
-		found = tag(name)
-		table.insert(private.tags, found)
-		private.tags_lookup[name] = found
-	end
-	return found
-end
-
-
-function public.aliases (name)
-	local tag = get_or_create_tag(name)
-	return function (aliases)
-		for _, name in pairs(aliases) do
-			private.tags_lookup[name] = alias(name, tag)
-		end
-	end
-end
-
-
-function public.headers (name)
-	local tag = get_or_create_tag(name)
-	return function (filenames)
-		for _, header in pairs(filenames) do
-			tag:add(header)
-		end
-	end
-end
-
-
-function public.include (tag)
-	tag = private.tags_lookup[tag] or error("invalid tag: " .. tag, 2)
-	return include(tag)
-end
-
-
-function public.remove (header)
-	return remove(header)
-end
-
-
-local db = loadfile(arg[1], nil, public)
-db()
-if arg[2] then
-	local tag = private.tags_lookup[arg[2]]
-	for _, header in pairs(tag.headers) do
-		print(header)
-	end
-else
-	for _, tag in pairs(private.tags_lookup) do
-		print(tag)
+local args = require "pl.lapp" [[
+Prints list of headers from a standard or available standards
+	-d  (string default 'db/')      Directory where definitions are placed
+	<selection>  (optional string)  Standard to display headers for
+]]
+local dir = require "pl.dir"
+local parse = require "headers.parser"
+local definitions = dir.getfiles(args.d, "*.lua")
+for _, filename in pairs(definitions) do
+	local handle = io.open(filename)
+	local data = handle:read("a")
+	handle:close()
+	if parse(data, args.selection) then
+		return  -- interface is yet to be properly defined, this allows only for first-result queries
 	end
 end
diff --git a/headers/definition.lua b/headers/definition.lua
new file mode 100644
index 0000000..82ce3b5
--- /dev/null
+++ b/headers/definition.lua
@@ -0,0 +1,49 @@
+--- Builds a definition parser that binds to a *private* object that implements +3,+41/private:/ callbacks.
+local
+function build (private)
+	local public = {}
+
+	--- scheme "headers/1"
+	function public.scheme (identifier)
+		if identifier ~= "headers/1" then
+			error("unknown scheme: " .. identifier, 2)
+		end
+	end
+
+	--- aliases "Formal Name" {"FN"}
+	--- aliases "New Formal Name" {"FN42"}
+	function public.aliases (tag)
+		tag = private:get_or_add_tag(tag)
+		return function (others)
+			for _, other in pairs(others) do
+				private:add_alias(tag, other)
+			end
+		end
+	end
+
+	--- headers "FN" {"a.fn", "b.fn"}
+	function public.headers (tag)
+		tag = private:get_or_add_tag(tag)
+		return function (entries)
+			for _, entry in pairs(entries) do
+				private:add_entry(tag, entry)
+			end
+		end
+	end
+
+	--- headers "FN42" {include "FN"}
+	function public.include (tag)
+		tag = private:get_tag(tag) or error("tag not found: " .. tag, 2)
+		return private:create_include(tag)
+	end
+
+	--- headers "FN42" {remove "a.fn"}
+	function public.remove (header)
+		return private:create_remove(header)
+	end
+
+	return public
+end
+
+
+return build
diff --git a/headers/parser.lua b/headers/parser.lua
new file mode 100644
index 0000000..e6895e6
--- /dev/null
+++ b/headers/parser.lua
@@ -0,0 +1,123 @@
+local build_definition = require "headers.definition"
+
+
+local tag do
+	local methods = {}
+	function methods:add (header)
+		table.insert(self.headers_, header)
+		return header
+	end
+	local function headers (self)
+		local result = {}
+		for _, value in pairs(self.headers_) do
+			if type(value) == "function" then
+				value(result)
+			else
+				table.insert(result, value)
+			end
+		end
+		return result
+	end
+	local mt = {
+		__tostring=function (self) return self.name end,
+		__index=function (self, key)
+			if key == "headers" then
+				return headers(self)
+			end
+			return methods[key]
+		end,
+	}
+	function tag (name)
+		return setmetatable({name=name, headers_={}}, mt)
+	end
+end
+
+
+local alias do
+	local mt = {
+		__tostring = function (self) return string.format("%s\t(%s)", self.name, tostring(self.tag)) end,
+		__index = function (self, key) return self.tag[key] end,
+	}
+	function alias (name, tag)
+		return setmetatable({name=name, tag=tag}, mt)
+	end
+end
+
+
+local private = {}
+private.tags = {}
+private.tag_lookup = {}
+
+
+function private:get_or_add_tag (name)
+	local found = self:get_tag(name)
+	if not found then
+		found = tag(name)
+		table.insert(self.tags, found)
+		self.tag_lookup[name] = found
+	end
+	return found
+end
+
+
+function private:get_tag (name)
+	return self.tag_lookup[name]
+end
+
+
+function private:add_alias (tag, name)
+	self.tag_lookup[name] = alias(name, tag)
+	return self.tag_lookup[name]
+end
+
+
+function private:add_entry (tag, entry)
+	return tag:add(entry)
+end
+
+
+function private:create_include (source)
+	return function (target)
+		for _, header in pairs(source.headers) do
+			table.insert(target, header)
+		end
+	end
+end
+
+
+function private:create_remove (header)
+	return function (target)
+		for key, value in pairs(target) do
+			if value == header then
+				table.remove(target, key)
+			end
+		end
+	end
+end
+
+
+function private:reset ()
+	self.tags = {}
+	self.tag_lookup = {}
+end
+
+
+return function (input, selection)
+	private:reset()  -- interface yet to be defined, this is a naive workaround to avoid retriggering prints
+	local db = load(input, nil, nil, build_definition(private))
+	db()
+	if selection then
+		local found = private:get_tag(selection)
+		if not found then
+			return false
+		end
+		for _, header in pairs(found.headers) do
+			print(header)
+		end
+	else
+		for _, tag in pairs(private.tag_lookup) do
+			print(tag)
+		end
+	end
+	return true
+end
diff --git a/spec/parser_spec.lua b/spec/parser_spec.lua
new file mode 100644
index 0000000..78ee8b8
--- /dev/null
+++ b/spec/parser_spec.lua
@@ -0,0 +1,16 @@
+local parse = require "headers.parser"
+
+
+describe("Scheme", function()
+	it("version one is supported", function()
+		assert.has_no.errors(function()
+			parse [[scheme "headers/1"]]
+		end)
+	end)
+
+	it("is not required", function()
+		assert.has_no.errors(function()
+			parse ""
+		end)
+	end)
+end)