.boilerplate{{{/+
    Copyright (c) 2006 Eric Anderton

    Permission is hereby granted, free of charge, to any person
    obtaining a copy of this software and associated documentation
    files (the "Software"), to deal in the Software without
    restriction, including without limitation the rights to use,
    copy, modify, merge, publish, distribute, sublicense, and/or
    sell copies of the Software, and to permit persons to whom the
    Software is furnished to do so, subject to the following
    conditions:

    The above copyright notice and this permission notice shall be
    included in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
    OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
    OTHER DEALINGS IN THE SOFTWARE.
+/}}}

#  Enki Grammar Definition (self-hosting frontend)
.module("enki.EnkiParser");

.import("enki.EnkiBackend");
.import("enki.Rule");
.import("enki.Expression");
.import("enki.Directive");

.define("bool","eoi","true","End of Input");
.define("bool","eol","true","End of Line");
.define("bool","err","true","Error");
.define("String","letter","true","Letter");
.define("String","digit","true","Digit");
.define("String","hexdigit","true","Hexdigit");
.define("String","any","true","any");
.define("String","newline","true","Newline");
.define("String","sp","true","Space(s)");
.define("String","ws","false","Whitespace");

.parsetype("String");
.utf("8");

.baseclass("BaseEnkiParser");
.classname("EnkiParser");


WS
	::=  ws [ (  SlashSlashComment |  SlashStarComment)  WS];


Syntax
	= void createSyntax(SyntaxLine[] lines)
	::=  WS { (  Rule:~lines |  Comment:~lines |  Directive:~lines)  WS} eoi;

# 
#  Rule and Predicate
# 

Rule
	= new Rule(String name,RulePredicate pred,Expression expr,RuleDecl decl)
	::=  Identifier:name  WS [  RuleDecl:decl  WS] [  RulePredicate:pred]  WS  "::="  WS  Expression:expr  WS  ";";

RuleDecl
	= new RuleDecl(Param[] params)
	::=  ParamsExpr:params;

RulePredicate
	= RulePredicate pred
	::=  "="  WS (  ClassPredicate:pred |  FunctionPredicate:pred |  BindingPredicate:pred);

ClassPredicate
	= new ClassPredicate(String name,Param[] params)
	::=  "new"  WS  Identifier:name  WS  ParamsExpr:params;

FunctionPredicate
	= new FunctionPredicate(Param decl,Param[] params)
	::=  ExplicitParam:decl  WS  ParamsExpr:params;

BindingPredicate
	= new BindingPredicate(Param param)
	::=  Param:param;

ParamsExpr
	= Param[] params
	::=  "("  WS [  Param:~params  WS {  ","  WS  Param:~params  WS}]  ")";

Param
	= Param param
	::=  ExplicitParam:param |  WeakParam:param;

WeakParam
	= new Param(String name)
	::=  Identifier:name;

ExplicitParam
	= new Param(bool isArray,String type,String name)
	::=  Identifier:type  WS [  "[]":isArray  Brackets  WS]  Identifier:name;

Brackets
	::= [  "[]"  Brackets];
# 
#  Expressions
# 

Expression
	= new Expression(Term[] terms)
	::=  Term:~terms  WS {  "|"  WS  Term:~terms  WS};

Term
	= SubExpression[] factors
	::=  SubExpression:~factors  WS {  SubExpression:~factors  WS};

SubExpression
	= SubExpression expr
	::=  Production:expr |  Substitution:expr |  Terminal:expr |  Range:expr |  Regexp:expr |  GroupExpr:expr |  OptionalExpr:expr |  ZeroOrMoreExpr:expr |  NegateExpr:expr |  TestExpr:expr |  LiteralExpr:expr |  CustomTerminal:expr;

Production
	= new Production(String name,Binding binding,ProductionArg[] args)
	::=  Identifier:name  WS [  "!("  WS  ProductionArg:~args {  WS  ","  WS  ProductionArg:~args} ")"] [  Binding:binding];

ProductionArg
	= ProductionArg arg
	::=  StringProductionArg:arg |  BindingProductionArg:arg;

StringProductionArg
	= new StringProductionArg(String value)
	::=  String:value;

BindingProductionArg
	= new BindingProductionArg(String value)
	::=  Identifier:value;

Substitution
	= new Substitution(String name,Binding binding)
	::=  "."  Identifier:name  WS [  Binding:binding];

GroupExpr
	= new GroupExpr(Expression expr,Binding binding)
	::=  "("  WS  Expression:expr  WS  ")"  WS [  Binding:binding];

OptionalExpr
	= new OptionalExpr(Expression expr,Binding binding)
	::=  "["  WS  Expression:expr  WS  "]"  WS [  Binding:binding];

ZeroOrMoreExpr
	= new ZeroOrMoreExpr(Expression expr,Binding binding,SubExpression term)
	::=  "{"  WS  Expression:expr  WS  "}"  WS [  Binding:binding  WS] [  SubExpression:term];

Terminal
	= new Terminal(String text,Binding binding)
	::=  String:text  WS [  Binding:binding];

Range
	= new Range(String start,String end,Binding binding)
	::=  HexExpr:start  WS [  "-"  WS  HexExpr:end  WS] [  Binding:binding];

Regexp
	= new Regexp(String text,Binding binding)
	::= (  "r"  String:text |  "`" {  any}:text "`")  WS [  Binding:binding];

NegateExpr
	= new Negate(SubExpression expr)
	::=  "!"  WS  SubExpression:expr;

TestExpr
	= new Test(SubExpression expr)
	::=  "/"  WS  SubExpression:expr;

LiteralExpr
	= new LiteralExpr(String name,Binding binding,ProductionArg[] args)
	::=  "@"  Identifier:name  WS [  "!("  WS  ProductionArg:~args {  WS  ","  WS  ProductionArg:~args} ")"] [  Binding:binding];

CustomTerminal
	= new CustomTerminal(String name,Binding binding)
	::=  "&"  Identifier:name  WS [  Binding:binding];

Binding
	= new Binding(bool isConcat,String name)
	::=  ":"  WS [  "~"]:isConcat   WS  Identifier:name;

Identifier
	= String value
	::= (  IdentifierStartChar {  IdentifierChar}):value ;

IdentifierStartChar
	= String text
	::= (  letter |  "_"):text ;

IdentifierChar
	= String text
	::= (  letter |  digit |  "_" |  "."):text ;

String
	= String text
	::= (  "\"" |  "\'"):~delim  {  AnyChar}:text.delim;

HexExpr
	= String text
	::=  "#" (  hexdigit  hexdigit [  hexdigit  hexdigit [  hexdigit  hexdigit  hexdigit  hexdigit [  hexdigit  hexdigit  hexdigit  hexdigit  hexdigit  hexdigit  hexdigit  hexdigit]]]):text ;

AnyChar
	= String value
	::= [  "\\":~value]  any:~value;

# 
#  Comments
# 


Comment
	= new Comment(String text)
	::=  PoundComment:text |  SlashSlashComment:text |  SlashStarComment:text;

PoundComment
	= String text
	::=  "#" {  any}:text eol;

SlashSlashComment
	= String text
	::=  "\x2F\x2F" {  any}:text eol;

SlashStarComment
	= String text
	::=  "\x2F\x2A" {  any}:text "\x2A\x2F";

# 
#  Directives
# 

Directive
	= Directive dir
	::=  "." (  ImportDirective:~dir |  BaseClassDirective:~dir |  ClassnameDirective:~dir |  DefineDirective:~dir |  IncludeDirective:~dir |  AliasDirective:~dir |  ModuleDirective:~dir |  CodeDirective:~dir |  TypelibDirective:~dir |  ParseTypeDirective:~dir |  BoilerplateDirective:~dir |  HeaderDirective:~dir |  UTFDirective:~dir);

ImportDirective
	= new ImportDirective(String imp)
	::=  "import"  WS  "("  WS  DirectiveArg:imp  WS  ")"  WS  ";";

BaseClassDirective
	= new BaseClassDirective(String name)
	::=  "baseclass"  WS  "("  WS  DirectiveArg:name  WS  ")"  WS  ";";

ClassnameDirective
	= new ClassnameDirective(String name)
	::=  "classname"  WS  "("  WS  DirectiveArg:name  WS  ")"  WS  ";";

DefineDirective
	= new DefineDirective(String returnType,String name,bool isTerminal,String description)
	::=  "define"  WS  "("  WS  DirectiveArg:returnType  WS  ","  WS  DirectiveArg:name  WS  ","  WS  DirectiveArg:isTerminal  WS [  ","  WS  DirectiveArg:description  WS]  ")"  WS  ";";

IncludeDirective
	= new IncludeDirective(String filename)
	::=  "include"  WS  "("  WS  String:filename  WS  ")"  WS  ";";

AliasDirective
	= new AliasDirective(String rule,String ruleAlias)
	::=  "alias"  WS  "("  WS  DirectiveArg:rule  WS  ","  WS  DirectiveArg:ruleAlias  WS  ")"  WS  ";";

ModuleDirective
	= new ModuleDirective(String moduleName)
	::=  "module"  WS  "("  WS  DirectiveArg:moduleName  WS  ")"  WS  ";";

CodeDirective
	= new CodeDirective(String code)
	::=  "code"  WS  "{{{" {  any}:code "}}}";

TypelibDirective
	= new TypelibDirective(String importName)
	::=  "typelib"  WS  "("  WS  DirectiveArg:importName  WS  ")"  WS  ";";

ParseTypeDirective
	= new ParseTypeDirective(String typeName)
	::=  "parsetype"  WS  "("  WS  DirectiveArg:typeName  WS  ")"  WS  ";";

BoilerplateDirective
	= new BoilerplateDirective(String code)
	::=  "boilerplate"  WS  "{{{" {  any}:code "}}}";

HeaderDirective
	= new HeaderDirective(String code)
	::=  "header"  WS  "{{{" {  any}:code "}}}";

UTFDirective
	= new UTFDirective(String value)
	::=  "utf"  WS  "("  WS  DirectiveArg:value  WS  ")"  WS  ";";

DirectiveArg
	= String arg
	::=  Identifier:arg |  String:arg;