/*
 * Mesa 3-D graphics library
 * Version:  6.5
 *
 * Copyright (C) 2004-2006  Brian Paul   All Rights Reserved.
 *
 * 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
 * BRIAN PAUL 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.
 */

/*
 * \file slang_shader.syn
 * slang vertex/fragment shader syntax
 * \author Michal Krol
 */

/*
 * usage:
 *   syn2c slang_shader.syn > slang_shader_syn.h
 *
 * when modifying or extending this file, several things must be taken into consideration:
 * - when adding new operators that were marked as reserved in the initial specification,
 *   one must only uncomment particular lines of code that refer to operators being added;
 * - when adding new shader target, one must reserve new value for shader_type register and
 *   use it in .if constructs for symbols that are exclusive for that shader;
 * - some symbols mimic output of other symbols - the best example is the "for" construct:
 *   expression "for (foo(); ; bar())" is seen as "for (foo(); true; bar())" by the output
 *   processor - hence, special care must be taken when rearranging output of essential symbols;
 * - order of single-quoted tokens does matter in alternatives - so do not parse "<" operator
 *   before "<<" and "<<" before "<<=";
 * - all double-quoted tokens are internally preprocessed to eliminate problems with parsing
 *   strings that are prefixes of other strings, like "sampler1D" and "sampler1DShadow";
 */

.syntax translation_unit;

/* revision number - increment after each change affecting emitted output */
.emtcode REVISION                                   4

/* external declaration (or precision or invariant stmt) */
.emtcode EXTERNAL_NULL                              0
.emtcode EXTERNAL_FUNCTION_DEFINITION               1
.emtcode EXTERNAL_DECLARATION                       2
.emtcode DEFAULT_PRECISION                          3
.emtcode INVARIANT_STMT                             4

/* precision */
.emtcode PRECISION_DEFAULT                          0
.emtcode PRECISION_LOW                              1
.emtcode PRECISION_MEDIUM                           2
.emtcode PRECISION_HIGH                             3

/* declaration */
.emtcode DECLARATION_FUNCTION_PROTOTYPE             1
.emtcode DECLARATION_INIT_DECLARATOR_LIST           2

/* function type */
.emtcode FUNCTION_ORDINARY                          0
.emtcode FUNCTION_CONSTRUCTOR                       1
.emtcode FUNCTION_OPERATOR                          2

/* operator type */
.emtcode OPERATOR_ADDASSIGN                         1
.emtcode OPERATOR_SUBASSIGN                         2
.emtcode OPERATOR_MULASSIGN                         3
.emtcode OPERATOR_DIVASSIGN                         4
/*.emtcode OPERATOR_MODASSIGN                         5*/
/*.emtcode OPERATOR_LSHASSIGN                         6*/
/*.emtcode OPERATOR_RSHASSIGN                         7*/
/*.emtcode OPERATOR_ORASSIGN                          8*/
/*.emtcode OPERATOR_XORASSIGN                         9*/
/*.emtcode OPERATOR_ANDASSIGN                         10*/
.emtcode OPERATOR_LOGICALXOR                        11
/*.emtcode OPERATOR_BITOR                             12*/
/*.emtcode OPERATOR_BITXOR                            13*/
/*.emtcode OPERATOR_BITAND                            14*/
.emtcode OPERATOR_LESS                              15
.emtcode OPERATOR_GREATER                           16
.emtcode OPERATOR_LESSEQUAL                         17
.emtcode OPERATOR_GREATEREQUAL                      18
/*.emtcode OPERATOR_LSHIFT                            19*/
/*.emtcode OPERATOR_RSHIFT                            20*/
.emtcode OPERATOR_MULTIPLY                          21
.emtcode OPERATOR_DIVIDE                            22
/*.emtcode OPERATOR_MODULUS                           23*/
.emtcode OPERATOR_INCREMENT                         24
.emtcode OPERATOR_DECREMENT                         25
.emtcode OPERATOR_PLUS                              26
.emtcode OPERATOR_MINUS                             27
/*.emtcode OPERATOR_COMPLEMENT                        28*/
.emtcode OPERATOR_NOT                               29

/* init declarator list */
.emtcode DECLARATOR_NONE                            0
.emtcode DECLARATOR_NEXT                            1

/* variable declaration */
.emtcode VARIABLE_NONE                              0
.emtcode VARIABLE_IDENTIFIER                        1
.emtcode VARIABLE_INITIALIZER                       2
.emtcode VARIABLE_ARRAY_EXPLICIT                    3
.emtcode VARIABLE_ARRAY_UNKNOWN                     4

/* type qualifier */
.emtcode TYPE_QUALIFIER_NONE                        0
.emtcode TYPE_QUALIFIER_CONST                       1
.emtcode TYPE_QUALIFIER_ATTRIBUTE                   2
.emtcode TYPE_QUALIFIER_VARYING                     3
.emtcode TYPE_QUALIFIER_UNIFORM                     4
.emtcode TYPE_QUALIFIER_FIXEDOUTPUT                 5
.emtcode TYPE_QUALIFIER_FIXEDINPUT                  6

/* type specifier */
.emtcode TYPE_SPECIFIER_VOID                        0
.emtcode TYPE_SPECIFIER_BOOL                        1
.emtcode TYPE_SPECIFIER_BVEC2                       2
.emtcode TYPE_SPECIFIER_BVEC3                       3
.emtcode TYPE_SPECIFIER_BVEC4                       4
.emtcode TYPE_SPECIFIER_INT                         5
.emtcode TYPE_SPECIFIER_IVEC2                       6
.emtcode TYPE_SPECIFIER_IVEC3                       7
.emtcode TYPE_SPECIFIER_IVEC4                       8
.emtcode TYPE_SPECIFIER_FLOAT                       9
.emtcode TYPE_SPECIFIER_VEC2                        10
.emtcode TYPE_SPECIFIER_VEC3                        11
.emtcode TYPE_SPECIFIER_VEC4                        12
.emtcode TYPE_SPECIFIER_MAT2                        13
.emtcode TYPE_SPECIFIER_MAT3                        14
.emtcode TYPE_SPECIFIER_MAT4                        15
.emtcode TYPE_SPECIFIER_SAMPLER1D                   16
.emtcode TYPE_SPECIFIER_SAMPLER2D                   17
.emtcode TYPE_SPECIFIER_SAMPLER3D                   18
.emtcode TYPE_SPECIFIER_SAMPLERCUBE                 19
.emtcode TYPE_SPECIFIER_SAMPLER1DSHADOW             20
.emtcode TYPE_SPECIFIER_SAMPLER2DSHADOW             21
.emtcode TYPE_SPECIFIER_SAMPLER2DRECT               22
.emtcode TYPE_SPECIFIER_SAMPLER2DRECTSHADOW         23
.emtcode TYPE_SPECIFIER_STRUCT                      24
.emtcode TYPE_SPECIFIER_TYPENAME                    25

/* OpenGL 2.1 */
.emtcode TYPE_SPECIFIER_MAT23                       26
.emtcode TYPE_SPECIFIER_MAT32                       27
.emtcode TYPE_SPECIFIER_MAT24                       28
.emtcode TYPE_SPECIFIER_MAT42                       29
.emtcode TYPE_SPECIFIER_MAT34                       30
.emtcode TYPE_SPECIFIER_MAT43                       31


/* structure field */
.emtcode FIELD_NONE                                 0
.emtcode FIELD_NEXT                                 1
.emtcode FIELD_ARRAY                                2

/* operation */
.emtcode OP_END                                     0
.emtcode OP_BLOCK_BEGIN_NO_NEW_SCOPE                1
.emtcode OP_BLOCK_BEGIN_NEW_SCOPE                   2
.emtcode OP_DECLARE                                 3
.emtcode OP_ASM                                     4
.emtcode OP_BREAK                                   5
.emtcode OP_CONTINUE                                6
.emtcode OP_DISCARD                                 7
.emtcode OP_RETURN                                  8
.emtcode OP_EXPRESSION                              9
.emtcode OP_IF                                      10
.emtcode OP_WHILE                                   11
.emtcode OP_DO                                      12
.emtcode OP_FOR                                     13
.emtcode OP_PUSH_VOID                               14
.emtcode OP_PUSH_BOOL                               15
.emtcode OP_PUSH_INT                                16
.emtcode OP_PUSH_FLOAT                              17
.emtcode OP_PUSH_IDENTIFIER                         18
.emtcode OP_SEQUENCE                                19
.emtcode OP_ASSIGN                                  20
.emtcode OP_ADDASSIGN                               21
.emtcode OP_SUBASSIGN                               22
.emtcode OP_MULASSIGN                               23
.emtcode OP_DIVASSIGN                               24
/*.emtcode OP_MODASSIGN                               25*/
/*.emtcode OP_LSHASSIGN                               26*/
/*.emtcode OP_RSHASSIGN                               27*/
/*.emtcode OP_ORASSIGN                                28*/
/*.emtcode OP_XORASSIGN                               29*/
/*.emtcode OP_ANDASSIGN                               30*/
.emtcode OP_SELECT                                  31
.emtcode OP_LOGICALOR                               32
.emtcode OP_LOGICALXOR                              33
.emtcode OP_LOGICALAND                              34
/*.emtcode OP_BITOR                                   35*/
/*.emtcode OP_BITXOR                                  36*/
/*.emtcode OP_BITAND                                  37*/
.emtcode OP_EQUAL                                   38
.emtcode OP_NOTEQUAL                                39
.emtcode OP_LESS                                    40
.emtcode OP_GREATER                                 41
.emtcode OP_LESSEQUAL                               42
.emtcode OP_GREATEREQUAL                            43
/*.emtcode OP_LSHIFT                                  44*/
/*.emtcode OP_RSHIFT                                  45*/
.emtcode OP_ADD                                     46
.emtcode OP_SUBTRACT                                47
.emtcode OP_MULTIPLY                                48
.emtcode OP_DIVIDE                                  49
/*.emtcode OP_MODULUS                                 50*/
.emtcode OP_PREINCREMENT                            51
.emtcode OP_PREDECREMENT                            52
.emtcode OP_PLUS                                    53
.emtcode OP_MINUS                                   54
/*.emtcode OP_COMPLEMENT                              55*/
.emtcode OP_NOT                                     56
.emtcode OP_SUBSCRIPT                               57
.emtcode OP_CALL                                    58
.emtcode OP_FIELD                                   59
.emtcode OP_POSTINCREMENT                           60
.emtcode OP_POSTDECREMENT                           61

/* parameter qualifier */
.emtcode PARAM_QUALIFIER_IN                         0
.emtcode PARAM_QUALIFIER_OUT                        1
.emtcode PARAM_QUALIFIER_INOUT                      2

/* function parameter */
.emtcode PARAMETER_NONE                             0
.emtcode PARAMETER_NEXT                             1

/* function parameter array presence */
.emtcode PARAMETER_ARRAY_NOT_PRESENT                0
.emtcode PARAMETER_ARRAY_PRESENT                    1

/* INVALID_EXTERNAL_DECLARATION seems to be reported when there's */
/* any syntax errors... */
.errtext INVALID_EXTERNAL_DECLARATION               "2001: Syntax error."
.errtext INVALID_OPERATOR_OVERRIDE                  "2002: Invalid operator override."
.errtext LBRACE_EXPECTED                            "2003: '{' expected but '$err_token$' found."
.errtext LPAREN_EXPECTED                            "2004: '(' expected but '$err_token$' found."
.errtext RPAREN_EXPECTED                            "2005: ')' expected but '$err_token$' found."
.errtext INVALID_PRECISION                          "2006: Invalid precision specifier '$err_token$'."
.errtext INVALID_PRECISION_TYPE                     "2007: Invalid precision type '$err_token$'."


/* tells whether the shader that is being parsed is a built-in shader or not */
/*   0 - normal behaviour */
/*   1 - accepts constructor and operator definitions and __asm statements */
/* the implementation will set it to 1 when compiling internal built-in shaders */
.regbyte parsing_builtin                            0

/* holds the type of the shader being parsed; possible values are listed below */
/*   FRAGMENT_SHADER            1 */
/*   VERTEX_SHADER              2 */
/* shader type is set by the caller before parsing */
.regbyte shader_type                                0

/*
    <variable_identifier>               ::= <identifier>
*/
variable_identifier
    identifier .emit OP_PUSH_IDENTIFIER;

/*
    <primary_expression>                ::= <variable_identifier>
                                          | <intconstant>
                                          | <floatconstant>
                                          | <boolconstant>
                                          | "(" <expression> ")"
*/
primary_expression
    floatconstant .or boolconstant .or intconstant .or variable_identifier .or primary_expression_1;
primary_expression_1
    lparen .and expression .and rparen;

/*
    <postfix_expression>                ::= <primary_expression>
                                          | <postfix_expression> "[" <integer_expression> "]"
                                          | <function_call>
                                          | <postfix_expression> "." <field_selection>
                                          | <postfix_expression> "++"
                                          | <postfix_expression> "--"
*/
postfix_expression
    postfix_expression_1 .and .loop postfix_expression_2;
postfix_expression_1
    function_call .or primary_expression;
postfix_expression_2
    postfix_expression_3 .or postfix_expression_4 .or
    plusplus .emit OP_POSTINCREMENT .or
    minusminus .emit OP_POSTDECREMENT;
postfix_expression_3
    lbracket .and integer_expression .and rbracket .emit OP_SUBSCRIPT;
postfix_expression_4
    dot .and field_selection .emit OP_FIELD;

/*
    <integer_expression>                ::= <expression>
*/
integer_expression
    expression;

/*
    <function_call>                     ::= <function_call_generic>
*/
function_call
    function_call_generic .emit OP_CALL .and .true .emit OP_END;

/*
    <function_call_generic>             ::= <function_call_header_with_parameters> ")"
                                          | <function_call_header_no_parameters> ")"
*/
function_call_generic
    function_call_generic_1 .or function_call_generic_2;
function_call_generic_1
    function_call_header_with_parameters .and rparen .error RPAREN_EXPECTED;
function_call_generic_2
    function_call_header_no_parameters .and rparen .error RPAREN_EXPECTED;

/*
    <function_call_header_no_parameters>::= <function_call_header> "void"
                                          | <function_call_header>
*/
function_call_header_no_parameters
    function_call_header .and function_call_header_no_parameters_1;
function_call_header_no_parameters_1
    "void" .or .true;

/*
    <function_call_header_with_parameters>::= <function_call_header> <assignment_expression>
                                            | <function_call_header_with_parameters> ","
                                              <assignment_expression>
*/
function_call_header_with_parameters
    function_call_header .and assignment_expression .and .true .emit OP_END .and
    .loop function_call_header_with_parameters_1;
function_call_header_with_parameters_1
    comma .and assignment_expression .and .true .emit OP_END;

/*
    <function_call_header>              ::= <function_identifier> "("
*/
function_call_header
    function_identifier .and lparen;

/*
    <function_identifier>               ::= <constructor_identifier>
                                          | <identifier>

note: <constructor_identifier> has been deleted
*/
function_identifier
    identifier;

/*
    <unary_expression>                  ::= <postfix_expression>
                                          | "++" <unary_expression>
                                          | "--" <unary_expression>
                                          | <unary_operator> <unary_expression>

    <unary_operator>                    ::= "+"
                                          | "-"
                                          | "!"
                                          | "~" // reserved
*/
unary_expression
    postfix_expression .or unary_expression_1 .or unary_expression_2 .or unary_expression_3 .or
    unary_expression_4 .or unary_expression_5/* .or unary_expression_6*/;
unary_expression_1
    plusplus .and unary_expression .and .true .emit OP_PREINCREMENT;
unary_expression_2
    minusminus .and unary_expression .and .true .emit OP_PREDECREMENT;
unary_expression_3
    plus .and unary_expression .and .true .emit OP_PLUS;
unary_expression_4
    minus .and unary_expression .and .true .emit OP_MINUS;
unary_expression_5
    bang .and unary_expression .and .true .emit OP_NOT;
/*unary_expression_6
    tilde .and unary_expression .and .true .emit OP_COMPLEMENT;*/

/*
    <multiplicative_expression>         ::= <unary_expression>
                                          | <multiplicative_expression> "*" <unary_expression>
                                          | <multiplicative_expression> "/" <unary_expression>
                                          | <multiplicative_expression> "%" <unary_expression> // reserved
*/
multiplicative_expression
    unary_expression .and .loop multiplicative_expression_1;
multiplicative_expression_1
    multiplicative_expression_2 .or multiplicative_expression_3/* .or multiplicative_expression_4*/;
multiplicative_expression_2
    star .and unary_expression .and .true .emit OP_MULTIPLY;
multiplicative_expression_3
    slash .and unary_expression .and .true .emit OP_DIVIDE;
/*multiplicative_expression_4
    percent .and unary_expression .and .true .emit OP_MODULUS;*/

/*
    <additive_expression>               ::= <multiplicative_expression>
                                          | <additive_expression> "+" <multiplicative_expression>
                                          | <additive_expression> "-" <multiplicative_expression>
*/
additive_expression
    multiplicative_expression .and .loop additive_expression_1;
additive_expression_1
    additive_expression_2 .or additive_expression_3;
additive_expression_2
    plus .and multiplicative_expression .and .true .emit OP_ADD;
additive_expression_3
    minus .and multiplicative_expression .and .true .emit OP_SUBTRACT;

/*
    <shift_expression>                  ::= <additive_expression>
                                          | <shift_expression> "<<" <additive_expression> // reserved
                                          | <shift_expression> ">>" <additive_expression> // reserved
*/
shift_expression
    additive_expression/* .and .loop shift_expression_1*/;
/*shift_expression_1
    shift_expression_2 .or shift_expression_3;*/
/*shift_expression_2
    lessless .and additive_expression .and .true .emit OP_LSHIFT;*/
/*shift_expression_3
    greatergreater .and additive_expression .and .true .emit OP_RSHIFT;*/

/*
    <relational_expression>             ::= <shift_expression>
                                          | <relational_expression> "<" <shift_expression>
                                          | <relational_expression> ">" <shift_expression>
                                          | <relational_expression> "<=" <shift_expression>
                                          | <relational_expression> ">=" <shift_expression>
*/
relational_expression
    shift_expression .and .loop relational_expression_1;
relational_expression_1
    relational_expression_2 .or relational_expression_3 .or relational_expression_4 .or
    relational_expression_5;
relational_expression_2
    lessequals .and shift_expression .and .true .emit OP_LESSEQUAL;
relational_expression_3
    greaterequals .and shift_expression .and .true .emit OP_GREATEREQUAL;
relational_expression_4
    less .and shift_expression .and .true .emit OP_LESS;
relational_expression_5
    greater .and shift_expression .and .true .emit OP_GREATER;

/*
    <equality_expression>               ::= <relational_expression>
                                          | <equality_expression> "==" <relational_expression>
                                          | <equality_expression> "!=" <relational_expression>
*/
equality_expression
    relational_expression .and .loop equality_expression_1;
equality_expression_1
    equality_expression_2 .or equality_expression_3;
equality_expression_2
    equalsequals .and relational_expression .and .true .emit OP_EQUAL;
equality_expression_3
    bangequals .and relational_expression .and .true .emit OP_NOTEQUAL;

/*
    <and_expression>                    ::= <equality_expression>
                                          | <and_expression> "&" <equality_expression> // reserved
*/
and_expression
    equality_expression/* .and .loop and_expression_1*/;
/*and_expression_1
    ampersand .and equality_expression .and .true .emit OP_BITAND;*/

/*
    <exclusive_or_expression>           ::= <and_expression>
                                          | <exclusive_or_expression> "^" <and_expression> // reserved
*/
exclusive_or_expression
    and_expression/* .and .loop exclusive_or_expression_1*/;
/*exclusive_or_expression_1
    caret .and and_expression .and .true .emit OP_BITXOR;*/

/*
    <inclusive_or_expression>           ::= <exclusive_or_expression>
                                          | <inclusive_or_expression> "|" <exclusive_or_expression> // reserved
*/
inclusive_or_expression
    exclusive_or_expression/* .and .loop inclusive_or_expression_1*/;
/*inclusive_or_expression_1
    bar .and exclusive_or_expression .and .true .emit OP_BITOR;*/

/*
    <logical_and_expression>            ::= <inclusive_or_expression>
                                          | <logical_and_expression> "&&" <inclusive_or_expression>
*/
logical_and_expression
    inclusive_or_expression .and .loop logical_and_expression_1;
logical_and_expression_1
    ampersandampersand .and inclusive_or_expression .and .true .emit OP_LOGICALAND;

/*
    <logical_xor_expression>            ::= <logical_and_expression>
                                          | <logical_xor_expression> "^^" <logical_and_expression>
*/
logical_xor_expression
    logical_and_expression .and .loop logical_xor_expression_1;
logical_xor_expression_1
    caretcaret .and logical_and_expression .and .true .emit OP_LOGICALXOR;

/*
    <logical_or_expression>             ::= <logical_xor_expression>
                                          | <logical_or_expression> "||" <logical_xor_expression>
*/
logical_or_expression
    logical_xor_expression .and .loop logical_or_expression_1;
logical_or_expression_1
    barbar .and logical_xor_expression .and .true .emit OP_LOGICALOR;

/*
    <conditional_expression>            ::= <logical_or_expression>
                                          | <logical_or_expression> "?" <expression> ":"
                                            <conditional_expression>
*/
conditional_expression
    logical_or_expression .and .loop conditional_expression_1;
conditional_expression_1
    question .and expression .and colon .and conditional_expression .and .true .emit OP_SELECT;

/*
    <assignment_expression>             ::= <conditional_expression>
                                          | <unary_expression> <assignment_operator>
                                            <assignment_expression>

    <assignment_operator>               ::= "="
                                          | "*="
                                          | "/="
                                          | "+="
                                          | "-="
                                          | "%=" // reserved
                                          | "<<=" // reserved
                                          | ">>=" // reserved
                                          | "&=" // reserved
                                          | "^=" // reserved
                                          | "|=" // reserved
*/
assignment_expression
    assignment_expression_1 .or assignment_expression_2 .or assignment_expression_3 .or
    assignment_expression_4 .or assignment_expression_5/* .or assignment_expression_6 .or
    assignment_expression_7 .or assignment_expression_8 .or assignment_expression_9 .or
    assignment_expression_10 .or assignment_expression_11*/ .or conditional_expression;
assignment_expression_1
    unary_expression .and equals .and assignment_expression .and .true .emit OP_ASSIGN;
assignment_expression_2
    unary_expression .and starequals .and assignment_expression .and .true .emit OP_MULASSIGN;
assignment_expression_3
    unary_expression .and slashequals .and assignment_expression .and .true .emit OP_DIVASSIGN;
assignment_expression_4
    unary_expression .and plusequals .and assignment_expression .and .true .emit OP_ADDASSIGN;
assignment_expression_5
    unary_expression .and minusequals .and assignment_expression .and .true .emit OP_SUBASSIGN;
/*assignment_expression_6
    unary_expression .and percentequals .and assignment_expression .and .true .emit OP_MODASSIGN;*/
/*assignment_expression_7
    unary_expression .and lesslessequals .and assignment_expression .and .true .emit OP_LSHASSIGN;*/
/*assignment_expression_8
    unary_expression .and greatergreaterequals .and assignment_expression .and
    .true .emit OP_RSHASSIGN;*/
/*assignment_expression_9
    unary_expression .and ampersandequals .and assignment_expression .and .true .emit OP_ANDASSIGN;*/
/*assignment_expression_10
    unary_expression .and caretequals .and assignment_expression .and .true .emit OP_XORASSIGN;*/
/*assignment_expression_11
    unary_expression .and barequals .and assignment_expression .and .true .emit OP_ORASSIGN;*/

/*
    <expression>                        ::= <assignment_expression>
                                          | <expression> "," <assignment_expression>
*/
expression
    assignment_expression .and .loop expression_1;
expression_1
    comma .and assignment_expression .and .true .emit OP_SEQUENCE;

/*
    <constant_expression>               ::= <conditional_expression>
*/
constant_expression
    conditional_expression .and .true .emit OP_END;

/*
    <declaration>                       ::= <function_prototype> ";"
                                          | <init_declarator_list> ";"
*/
declaration
    declaration_1 .or declaration_2;
declaration_1
    function_prototype .emit DECLARATION_FUNCTION_PROTOTYPE .and semicolon;
declaration_2
    init_declarator_list .emit DECLARATION_INIT_DECLARATOR_LIST .and semicolon;

/*
    <function_prototype>                ::= <function_header> "void" ")"
                                          | <function_declarator> ")"
*/
function_prototype
    function_prototype_1 .or function_prototype_2;
function_prototype_1
    function_header .and "void" .and rparen .error RPAREN_EXPECTED .emit PARAMETER_NONE;
function_prototype_2
    function_declarator .and rparen .error RPAREN_EXPECTED .emit PARAMETER_NONE;

/*
    <function_declarator>               ::= <function_header>
                                          | <function_header_with_parameters>
*/
function_declarator
    function_header_with_parameters .or function_header;

/*
    <function_header_with_parameters>   ::= <function_header> <parameter_declaration>
                                          | <function_header_with_parameters> ","
                                            <parameter_declaration>
*/
function_header_with_parameters
    function_header .and parameter_declaration .and .loop function_header_with_parameters_1;
function_header_with_parameters_1
    comma .and parameter_declaration;

/*
    <function_header>                   ::= <fully_specified_type> <identifier> "("
*/
function_header
    function_header_nospace .or function_header_space;
function_header_space
    fully_specified_type_space .and space .and function_decl_identifier .and lparen;
function_header_nospace
    fully_specified_type_nospace .and function_decl_identifier .and lparen;

/*
    <function_decl_identifier>          ::= "__constructor"
                                          | <__operator>
                                          | <identifier>

note: this is an extension to the standard language specification - normally slang disallows
      operator and constructor prototypes and definitions
*/
function_decl_identifier
    .if (parsing_builtin != 0) __operator .emit FUNCTION_OPERATOR .or
    .if (parsing_builtin != 0) "__constructor" .emit FUNCTION_CONSTRUCTOR .or
    identifier .emit FUNCTION_ORDINARY;

/*
    <__operator>                        ::= "__operator" <overriden_op>

note: this is an extension to the standard language specification - normally slang disallows
      operator prototypes and definitions
*/
__operator
    "__operator" .and overriden_operator .error INVALID_OPERATOR_OVERRIDE;

/*
    <overriden_op>                      ::= "="
                                          | "+="
                                          | "-="
                                          | "*="
                                          | "/="
                                          | "%=" // reserved
                                          | "<<=" // reserved
                                          | ">>=" // reserved
                                          | "&=" // reserved
                                          | "^=" // reserved
                                          | "|=" // reserved
                                          | "^^"
                                          | "|" // reserved
                                          | "^" // reserved
                                          | "&" // reserved
                                          | "=="
                                          | "!="
                                          | "<"
                                          | ">"
                                          | "<="
                                          | ">="
                                          | "<<" // reserved
                                          | ">>" // reserved
                                          | "*"
                                          | "/"
                                          | "%" // reserved
                                          | "++"
                                          | "--"
                                          | "+"
                                          | "-"
                                          | "~" // reserved
                                          | "!"

note: this is an extension to the standard language specification - normally slang disallows
      operator prototypes and definitions
*/
overriden_operator
    plusplus .emit OPERATOR_INCREMENT .or
    plusequals .emit OPERATOR_ADDASSIGN .or
    plus .emit OPERATOR_PLUS .or
    minusminus .emit OPERATOR_DECREMENT .or
    minusequals .emit OPERATOR_SUBASSIGN .or
    minus .emit OPERATOR_MINUS .or
    bang .emit OPERATOR_NOT .or
    starequals .emit OPERATOR_MULASSIGN .or
    star .emit OPERATOR_MULTIPLY .or
    slashequals .emit OPERATOR_DIVASSIGN .or
    slash .emit OPERATOR_DIVIDE .or
    lessequals .emit OPERATOR_LESSEQUAL .or
    /*lesslessequals .emit OPERATOR_LSHASSIGN .or*/
    /*lessless .emit OPERATOR_LSHIFT .or*/
    less .emit OPERATOR_LESS .or
    greaterequals .emit OPERATOR_GREATEREQUAL .or
    /*greatergreaterequals .emit OPERATOR_RSHASSIGN .or*/
    /*greatergreater .emit OPERATOR_RSHIFT .or*/
    greater .emit OPERATOR_GREATER .or
    /*percentequals .emit OPERATOR_MODASSIGN .or*/
    /*percent .emit OPERATOR_MODULUS .or*/
    /*ampersandequals .emit OPERATOR_ANDASSIGN */
    /*ampersand .emit OPERATOR_BITAND .or*/
    /*barequals .emit OPERATOR_ORASSIGN .or*/
    /*bar .emit OPERATOR_BITOR .or*/
    /*tilde .emit OPERATOR_COMPLEMENT .or*/
    /*caretequals .emit OPERATOR_XORASSIGN .or*/
    caretcaret .emit OPERATOR_LOGICALXOR /*.or
    caret .emit OPERATOR_BITXOR*/;

/*
    <parameter_declarator>              ::= <type_specifier> <identifier>
                                          | <type_specifier> <identifier> "[" <constant_expression>
                                            "]"
*/
parameter_declarator
    parameter_declarator_nospace .or parameter_declarator_space;
parameter_declarator_nospace
    type_specifier_nospace .and identifier .and parameter_declarator_1;
parameter_declarator_space
    type_specifier_space .and space .and identifier .and parameter_declarator_1;
parameter_declarator_1
    parameter_declarator_2 .emit PARAMETER_ARRAY_PRESENT .or
    .true .emit PARAMETER_ARRAY_NOT_PRESENT;
parameter_declarator_2
    lbracket .and constant_expression .and rbracket;

/*
    <parameter_declaration>             ::= <type_qualifier> <parameter_qualifier>
                                            <parameter_declarator>
                                          | <type_qualifier> <parameter_qualifier>
                                            <parameter_type_specifier>
                                          | <parameter_qualifier> <parameter_declarator>
                                          | <parameter_qualifier> <parameter_type_specifier>
*/
parameter_declaration
    parameter_declaration_1 .emit PARAMETER_NEXT;
parameter_declaration_1
    parameter_declaration_2 .or parameter_declaration_3;
parameter_declaration_2
    type_qualifier .and space .and parameter_qualifier .and parameter_declaration_4;
parameter_declaration_3
    parameter_qualifier .emit TYPE_QUALIFIER_NONE .and parameter_declaration_4;
parameter_declaration_4
    parameter_declarator .or parameter_type_specifier;

/*
    <parameter_qualifier>               ::= "in"
                                          | "out"
                                          | "inout"
                                          | ""
*/
parameter_qualifier
    parameter_qualifier_1 .or .true .emit PARAM_QUALIFIER_IN;
parameter_qualifier_1
    parameter_qualifier_2 .and space;
parameter_qualifier_2
    "in" .emit PARAM_QUALIFIER_IN .or
    "out" .emit PARAM_QUALIFIER_OUT .or
    "inout" .emit PARAM_QUALIFIER_INOUT;

/*
    <parameter_type_specifier>          ::= <type_specifier>
                                          | <type_specifier> "[" <constant_expression> "]"
*/
parameter_type_specifier
    parameter_type_specifier_1 .and .true .emit '\0' .and parameter_type_specifier_2;
parameter_type_specifier_1
    type_specifier_nospace .or type_specifier_space;
parameter_type_specifier_2
    parameter_type_specifier_3 .emit PARAMETER_ARRAY_PRESENT .or
    .true .emit PARAMETER_ARRAY_NOT_PRESENT;
parameter_type_specifier_3
    lbracket .and constant_expression .and rbracket;

/*
    <init_declarator_list>              ::= <single_declaration>
                                          | <init_declarator_list> "," <identifier>
                                          | <init_declarator_list> "," <identifier> "[" "]"
                                          | <init_declarator_list> "," <identifier> "["
                                            <constant_expression> "]"
                                          | <init_declarator_list> "," <identifier> "="
                                            <initializer>
*/
init_declarator_list
    single_declaration .and .loop init_declarator_list_1 .emit DECLARATOR_NEXT .and
    .true .emit DECLARATOR_NONE;
init_declarator_list_1
    comma .and identifier .emit VARIABLE_IDENTIFIER .and init_declarator_list_2;
init_declarator_list_2
    init_declarator_list_3 .or init_declarator_list_4 .or .true .emit VARIABLE_NONE;
init_declarator_list_3
    equals .and initializer .emit VARIABLE_INITIALIZER;
init_declarator_list_4
    lbracket .and init_declarator_list_5 .and rbracket;
init_declarator_list_5
    constant_expression .emit VARIABLE_ARRAY_EXPLICIT .or .true .emit VARIABLE_ARRAY_UNKNOWN;

/*
    <single_declaration>                ::= <fully_specified_type>
                                          | <fully_specified_type> <identifier>
                                          | <fully_specified_type> <identifier> "[" "]"
                                          | <fully_specified_type> <identifier> "["
                                            <constant_expression> "]"
                                          | <fully_specified_type> <identifier> "=" <initializer>
*/
single_declaration
    single_declaration_nospace .or single_declaration_space;
single_declaration_space
    fully_specified_type_space .and single_declaration_space_1;
single_declaration_nospace
    fully_specified_type_nospace .and single_declaration_nospace_1;
single_declaration_space_1
    single_declaration_space_2 .emit VARIABLE_IDENTIFIER .or .true .emit VARIABLE_NONE;
single_declaration_nospace_1
    single_declaration_nospace_2 .emit VARIABLE_IDENTIFIER .or .true .emit VARIABLE_NONE;
single_declaration_space_2
    space .and identifier .and single_declaration_3;
single_declaration_nospace_2
    identifier .and single_declaration_3;
single_declaration_3
    single_declaration_4 .or single_declaration_5 .or .true .emit VARIABLE_NONE;
single_declaration_4
    equals .and initializer .emit VARIABLE_INITIALIZER;
single_declaration_5
    lbracket .and single_declaration_6 .and rbracket;
single_declaration_6
    constant_expression .emit VARIABLE_ARRAY_EXPLICIT .or .true .emit VARIABLE_ARRAY_UNKNOWN;

/*
    <fully_specified_type>              ::= <type_specifier>
                                          | <type_qualifier> <type_specifier>
                                          | <precision> <type_specifier>
                                          | <type_qualifier> <precision> <type_specifier>
*/
fully_specified_type_space
    fully_specified_type_optqual .and fully_specified_type_optprec .and type_specifier_space;
fully_specified_type_nospace
    fully_specified_type_optqual .and fully_specified_type_optprec .and type_specifier_nospace;
fully_specified_type_optqual
    fully_specified_type_qual .or .true .emit TYPE_QUALIFIER_NONE;
fully_specified_type_qual
    type_qualifier .and space;
fully_specified_type_optprec
    fully_specified_type_prec .or .true .emit PRECISION_DEFAULT;
fully_specified_type_prec
    precision .and space;

/*
    <type_qualifier>                    ::= "const"
                                          | "attribute" // Vertex only.
                                          | "varying"
                                          | "uniform"
										  | "__fixed_output"
										  | "__fixed_input"

note: this is an extension to the standard language specification - normally slang disallows
      __fixed_output and __fixed_input type qualifiers
*/
type_qualifier
    "const" .emit TYPE_QUALIFIER_CONST .or
    .if (shader_type == 2) "attribute" .emit TYPE_QUALIFIER_ATTRIBUTE .or
    "varying" .emit TYPE_QUALIFIER_VARYING .or
    "uniform" .emit TYPE_QUALIFIER_UNIFORM .or
	.if (parsing_builtin != 0) "__fixed_output" .emit TYPE_QUALIFIER_FIXEDOUTPUT .or
	.if (parsing_builtin != 0) "__fixed_input" .emit TYPE_QUALIFIER_FIXEDINPUT;

/*
    <type_specifier>                    ::= "void"
                                          | "float"
                                          | "int"
                                          | "bool"
                                          | "vec2"
                                          | "vec3"
                                          | "vec4"
                                          | "bvec2"
                                          | "bvec3"
                                          | "bvec4"
                                          | "ivec2"
                                          | "ivec3"
                                          | "ivec4"
                                          | "mat2"
                                          | "mat3"
                                          | "mat4"
                                          | "mat2x3"
                                          | "mat3x2"
                                          | "mat2x4"
                                          | "mat4x2"
                                          | "mat3x4"
                                          | "mat4x3"
                                          | "sampler1D"
                                          | "sampler2D"
                                          | "sampler3D"
                                          | "samplerCube"
                                          | "sampler1DShadow"
                                          | "sampler2DShadow"
					  | "sampler2DRect"
					  | "sampler2DRectShadow"
                                          | <struct_specifier>
                                          | <type_name>
*/
type_specifier_space
    "void" .emit TYPE_SPECIFIER_VOID .or
    "float" .emit TYPE_SPECIFIER_FLOAT .or
    "int" .emit TYPE_SPECIFIER_INT .or
    "bool" .emit TYPE_SPECIFIER_BOOL .or
    "vec2" .emit TYPE_SPECIFIER_VEC2 .or
    "vec3" .emit TYPE_SPECIFIER_VEC3 .or
    "vec4" .emit TYPE_SPECIFIER_VEC4 .or
    "bvec2" .emit TYPE_SPECIFIER_BVEC2 .or
    "bvec3" .emit TYPE_SPECIFIER_BVEC3 .or
    "bvec4" .emit TYPE_SPECIFIER_BVEC4 .or
    "ivec2" .emit TYPE_SPECIFIER_IVEC2 .or
    "ivec3" .emit TYPE_SPECIFIER_IVEC3 .or
    "ivec4" .emit TYPE_SPECIFIER_IVEC4 .or
    "mat2" .emit TYPE_SPECIFIER_MAT2 .or
    "mat3" .emit TYPE_SPECIFIER_MAT3 .or
    "mat4" .emit TYPE_SPECIFIER_MAT4 .or
    "mat2x3" .emit TYPE_SPECIFIER_MAT23 .or
    "mat3x2" .emit TYPE_SPECIFIER_MAT32 .or
    "mat2x4" .emit TYPE_SPECIFIER_MAT24 .or
    "mat4x2" .emit TYPE_SPECIFIER_MAT42 .or
    "mat3x4" .emit TYPE_SPECIFIER_MAT34 .or
    "mat4x3" .emit TYPE_SPECIFIER_MAT43 .or
    "sampler1D" .emit TYPE_SPECIFIER_SAMPLER1D .or
    "sampler2D" .emit TYPE_SPECIFIER_SAMPLER2D .or
    "sampler3D" .emit TYPE_SPECIFIER_SAMPLER3D .or
    "samplerCube" .emit TYPE_SPECIFIER_SAMPLERCUBE .or
    "sampler1DShadow" .emit TYPE_SPECIFIER_SAMPLER1DSHADOW .or
    "sampler2DShadow" .emit TYPE_SPECIFIER_SAMPLER2DSHADOW .or
    "sampler2DRect" .emit TYPE_SPECIFIER_SAMPLER2DRECT .or
    "sampler2DRectShadow" .emit TYPE_SPECIFIER_SAMPLER2DRECTSHADOW .or
    type_name .emit TYPE_SPECIFIER_TYPENAME;
type_specifier_nospace
    struct_specifier .emit TYPE_SPECIFIER_STRUCT;

/*
    <struct_specifier>                  ::= "struct" <identifier> "{" <struct_declaration_list> "}"
                                          | "struct" "{" <struct_declaration_list> "}"
*/
struct_specifier
    "struct" .and struct_specifier_1 .and optional_space .and lbrace .error LBRACE_EXPECTED .and
    struct_declaration_list .and rbrace .emit FIELD_NONE;
struct_specifier_1
    struct_specifier_2 .or .true .emit '\0';
struct_specifier_2
    space .and identifier;

/*
    <struct_declaration_list>           ::= <struct_declaration>
                                          | <struct_declaration_list> <struct_declaration>
*/
struct_declaration_list
    struct_declaration .and .loop struct_declaration .emit FIELD_NEXT;

/*
    <struct_declaration>                ::= <type_specifier> <struct_declarator_list> ";"
*/
struct_declaration
    struct_declaration_nospace .or struct_declaration_space;
struct_declaration_space
    type_specifier_space .and space .and struct_declarator_list .and semicolon .emit FIELD_NONE;
struct_declaration_nospace
    type_specifier_nospace .and struct_declarator_list .and semicolon .emit FIELD_NONE;

/*
    <struct_declarator_list>            ::= <struct_declarator>
                                          | <struct_declarator_list> "," <struct_declarator>
*/
struct_declarator_list
    struct_declarator .and .loop struct_declarator_list_1 .emit FIELD_NEXT;
struct_declarator_list_1
    comma .and struct_declarator;

/*
    <struct_declarator>                 ::= <identifier>
                                          | <identifier> "[" <constant_expression> "]"
*/
struct_declarator
    identifier .and struct_declarator_1;
struct_declarator_1
    struct_declarator_2 .emit FIELD_ARRAY .or .true .emit FIELD_NONE;
struct_declarator_2
    lbracket .and constant_expression .and rbracket;

/*
    <initializer>                       ::= <assignment_expression>
*/
initializer
    assignment_expression .and .true .emit OP_END;

/*
    <declaration_statement>             ::= <declaration>
*/
declaration_statement
    declaration;

/*
    <statement>                         ::= <compound_statement>
                                          | <simple_statement>
*/
statement
    compound_statement .or simple_statement;
statement_space
    compound_statement .or statement_space_1;
statement_space_1
    space .and simple_statement;

/*
    <simple_statement>                  ::= <__asm_statement>
                                          | <selection_statement>
                                          | <iteration_statement>
                                          | <jump_statement>
                                          | <expression_statement>
                                          | <declaration_statement>

note: this is an extension to the standard language specification - normally slang disallows
      use of __asm statements
*/
simple_statement
    .if (parsing_builtin != 0) __asm_statement .emit OP_ASM .or
    selection_statement .or
    iteration_statement .or
    jump_statement .or
    expression_statement .emit OP_EXPRESSION .or
    declaration_statement .emit OP_DECLARE;

/*
    <compound_statement>                ::= "{" "}"
                                          | "{" <statement_list> "}"
*/
compound_statement
    compound_statement_1 .emit OP_BLOCK_BEGIN_NEW_SCOPE .and .true .emit OP_END;
compound_statement_1
    compound_statement_2 .or compound_statement_3;
compound_statement_2
    lbrace .and rbrace;
compound_statement_3
    lbrace .and statement_list .and rbrace;

/*
    <statement_no_new_scope>            ::= <compound_statement_no_new_scope>
                                          | <simple_statement>
*/
statement_no_new_scope
    compound_statement_no_new_scope .or simple_statement;

/*
    <compound_statement_no_new_scope>   ::= "{" "}"
                                          | "{" <statement_list> "}"
*/
compound_statement_no_new_scope
    compound_statement_no_new_scope_1 .emit OP_BLOCK_BEGIN_NO_NEW_SCOPE .and .true .emit OP_END;
compound_statement_no_new_scope_1
    compound_statement_no_new_scope_2 .or compound_statement_no_new_scope_3;
compound_statement_no_new_scope_2
    lbrace .and rbrace;
compound_statement_no_new_scope_3
    lbrace .and statement_list .and rbrace;

/*
    <statement_list>                    ::= <statement>
                                          | <statement_list> <statement>
*/
statement_list
    statement .and .loop statement;

/*
    <expression_statement>              ::= ";"
                                          | <expression> ";"
*/
expression_statement
    expression_statement_1 .or expression_statement_2;
expression_statement_1
    semicolon .emit OP_PUSH_VOID .emit OP_END;
expression_statement_2
    expression .and semicolon .emit OP_END;

/*
    <selection_statement>               ::= "if" "(" <expression> ")" <selection_rest_statement>
*/
selection_statement
    "if" .emit OP_IF .and lparen .error LPAREN_EXPECTED .and expression .and
    rparen .error RPAREN_EXPECTED .emit OP_END .and selection_rest_statement;

/*
    <selection_rest_statement>          ::= <statement> "else" <statement>
                                          | <statement>
*/
selection_rest_statement
    statement .and selection_rest_statement_1;
selection_rest_statement_1
    selection_rest_statement_2 .or .true .emit OP_EXPRESSION .emit OP_PUSH_VOID .emit OP_END;
selection_rest_statement_2
    "else" .and optional_space .and statement;

/*
    <condition>                         ::= <expression>
                                          | <fully_specified_type> <identifier> "=" <initializer>

note: if <condition_1> is executed, the emit format must match <declaration> emit format
*/
condition
    condition_1 .emit OP_DECLARE .emit DECLARATION_INIT_DECLARATOR_LIST .or
    condition_3 .emit OP_EXPRESSION;
condition_1
    condition_1_nospace .or condition_1_space;
condition_1_nospace
    fully_specified_type_nospace .and condition_2;
condition_1_space
    fully_specified_type_space .and space .and condition_2;
condition_2
    identifier .emit VARIABLE_IDENTIFIER .and equals .emit VARIABLE_INITIALIZER .and
    initializer .and .true .emit DECLARATOR_NONE;
condition_3
    expression .and .true .emit OP_END;

/*
    <iteration_statement>               ::= "while" "(" <condition> ")" <statement>
                                          | "do" <statement> "while" "(" <expression> ")" ";"
                                          | "for" "(" <for_init_statement> <for_rest_statement> ")"
                                            <statement_no_new_scope>
*/
iteration_statement
    iteration_statement_1 .or iteration_statement_2 .or iteration_statement_3;
iteration_statement_1
    "while" .emit OP_WHILE .and lparen .error LPAREN_EXPECTED .and condition .and
    rparen .error RPAREN_EXPECTED .and statement;
iteration_statement_2
    "do" .emit OP_DO .and statement_space .and "while" .and lparen .error LPAREN_EXPECTED .and
    expression .and rparen .error RPAREN_EXPECTED .emit OP_END .and semicolon;
iteration_statement_3
    "for" .emit OP_FOR .and lparen .error LPAREN_EXPECTED .and for_init_statement .and
    for_rest_statement .and rparen .error RPAREN_EXPECTED .and statement_no_new_scope;

/*
    <for_init_statement>                ::= <expression_statement>
                                          | <declaration_statement>
*/
for_init_statement
    expression_statement .emit OP_EXPRESSION .or declaration_statement .emit OP_DECLARE;

/*
    <conditionopt>                      ::= <condition>
                                          | ""

note: <conditionopt> is used only by "for" statement - if <condition> is ommitted, parser
      simulates default behaviour, that is simulates "true" expression
*/
conditionopt
    condition .or
    .true .emit OP_EXPRESSION .emit OP_PUSH_BOOL .emit 2 .emit '1' .emit '\0' .emit OP_END;

/*
    <for_rest_statement>                ::= <conditionopt> ";"
                                          | <conditionopt> ";" <expression>
*/
for_rest_statement
    conditionopt .and semicolon .and for_rest_statement_1;
for_rest_statement_1
    for_rest_statement_2 .or .true .emit OP_PUSH_VOID .emit OP_END;
for_rest_statement_2
    expression .and .true .emit OP_END;

/*
    <jump_statement>                    ::= "continue" ";"
                                          | "break" ";"
                                          | "return" ";"
                                          | "return" <expression> ";"
                                          | "discard" ";" // Fragment shader only.
*/
jump_statement
    jump_statement_1 .or jump_statement_2 .or jump_statement_3 .or jump_statement_4 .or
    .if (shader_type == 1) jump_statement_5;
jump_statement_1
    "continue" .and semicolon .emit OP_CONTINUE;
jump_statement_2
    "break" .and semicolon .emit OP_BREAK;
jump_statement_3
    "return" .emit OP_RETURN .and optional_space .and expression .and semicolon .emit OP_END;
jump_statement_4
    "return" .emit OP_RETURN .and semicolon .emit OP_PUSH_VOID .emit OP_END;
jump_statement_5
    "discard" .and semicolon .emit OP_DISCARD;

/*
    <__asm_statement>                   ::= "__asm" <identifier> <asm_arguments> ";"

note: this is an extension to the standard language specification - normally slang disallows
      __asm statements
*/
__asm_statement
    "__asm" .and space .and identifier .and space .and asm_arguments .and semicolon .emit OP_END;

/*
    <asm_arguments>                     ::= <asm_argument>
                                          | <asm_arguments> "," <asm_argument>

note: this is an extension to the standard language specification - normally slang disallows
      __asm statements
*/
asm_arguments
    asm_argument .and .true .emit OP_END .and .loop asm_arguments_1;
asm_arguments_1
    comma .and asm_argument .and .true .emit OP_END;

/*
    <asm_argument>                      ::= <variable_identifier>
                                          | <floatconstant>

note: this is an extension to the standard language specification - normally slang disallows
      __asm statements
*/
asm_argument
    var_with_field .or
    variable_identifier .or
    floatconstant;

var_with_field
    variable_identifier .and dot .and field_selection .emit OP_FIELD;


/*
 *  <translation_unit>                  ::= <external_declaration>
 *                                        | <translation_unit> <external_declaration>
 */
translation_unit
    optional_space .emit REVISION .and external_declaration .error INVALID_EXTERNAL_DECLARATION .and
    .loop external_declaration .and optional_space .and
    '\0' .error INVALID_EXTERNAL_DECLARATION .emit EXTERNAL_NULL;


/*
 *  <external_declaration>              ::= <function_definition>
 *                                        | <declaration>
 */
external_declaration
    precision_stmt .emit DEFAULT_PRECISION .or
    invariant_stmt .emit INVARIANT_STMT .or
    function_definition .emit EXTERNAL_FUNCTION_DEFINITION .or
    declaration .emit EXTERNAL_DECLARATION;


/*
 * <precision_stmt>    ::= "precision" <precision> <prectype>
 */
precision_stmt
    "precision" .and space .and precision .error INVALID_PRECISION .and space .and prectype .error INVALID_PRECISION_TYPE .and semicolon;

/*
 * <precision>           ::= "lowp"
 *                         | "mediump"
 *                         | "highp"
 */
precision
    "lowp" .emit PRECISION_LOW .or
    "mediump" .emit PRECISION_MEDIUM .or
    "highp" .emit PRECISION_HIGH;

/*
 * <prectype> ::= "int"
 *              | "float"
 *              | "a sampler type"
 */
prectype
    "int" .emit TYPE_SPECIFIER_INT .or
    "float" .emit TYPE_SPECIFIER_FLOAT .or
    "sampler1D" .emit TYPE_SPECIFIER_SAMPLER1D .or
    "sampler2D" .emit TYPE_SPECIFIER_SAMPLER2D .or
    "sampler3D" .emit TYPE_SPECIFIER_SAMPLER3D .or
    "samplerCube" .emit TYPE_SPECIFIER_SAMPLERCUBE .or
    "sampler1DShadow" .emit TYPE_SPECIFIER_SAMPLER1DSHADOW .or
    "sampler2DShadow" .emit TYPE_SPECIFIER_SAMPLER2DSHADOW .or
    "sampler2DRect" .emit TYPE_SPECIFIER_SAMPLER2DRECT .or
    "sampler2DRectShadow" .emit TYPE_SPECIFIER_SAMPLER2DRECTSHADOW;


/*
 * <invariant_stmt>    ::= "invariant" identifier;
 */
invariant_stmt
    "invariant" .and space .and identifier .and semicolon;


/*
    <function_definition>               :: <function_prototype> <compound_statement_no_new_scope>
*/
function_definition
    function_prototype .and compound_statement_no_new_scope;

/* helper rulez, not part of the official language syntax */

digit_oct
    '0'-'7';

digit_dec
    '0'-'9';

digit_hex
    '0'-'9' .or 'A'-'F' .or 'a'-'f';

id_character_first
    'a'-'z' .or 'A'-'Z' .or '_';

id_character_next
    id_character_first .or digit_dec;

identifier
    id_character_first .emit * .and .loop id_character_next .emit * .and .true .emit '\0';

float
    float_1 .or float_2;
float_1
    float_fractional_constant .and float_optional_exponent_part;
float_2
    float_digit_sequence .and .true .emit '\0' .and float_exponent_part;

float_fractional_constant
    float_fractional_constant_1 .or float_fractional_constant_2 .or float_fractional_constant_3;
float_fractional_constant_1
    float_digit_sequence .and '.' .and float_digit_sequence;
float_fractional_constant_2
    float_digit_sequence .and '.' .and .true .emit '\0';
float_fractional_constant_3
    '.' .emit '\0' .and float_digit_sequence;

float_optional_exponent_part
    float_exponent_part .or .true .emit '\0';

float_digit_sequence
    digit_dec .emit * .and .loop digit_dec .emit * .and .true .emit '\0';

float_exponent_part
    float_exponent_part_1 .or float_exponent_part_2;
float_exponent_part_1
    'e' .and float_optional_sign .and float_digit_sequence;
float_exponent_part_2
    'E' .and float_optional_sign .and float_digit_sequence;

float_optional_sign
    float_sign .or .true;

float_sign
    '+' .or '-' .emit '-';

integer
    integer_hex .or integer_oct .or integer_dec;

integer_hex
    '0' .and integer_hex_1 .emit 0x10 .and digit_hex .emit * .and .loop digit_hex .emit * .and
    .true .emit '\0';
integer_hex_1
    'x' .or 'X';

integer_oct
    '0' .emit 8 .emit * .and .loop digit_oct .emit * .and .true .emit '\0';

integer_dec
    digit_dec .emit 10 .emit * .and .loop digit_dec .emit * .and .true .emit '\0';

boolean
    "true" .emit 2 .emit '1' .emit '\0' .or
    "false" .emit 2 .emit '0' .emit '\0';

type_name
    identifier;

field_selection
    identifier;

floatconstant
    float .emit OP_PUSH_FLOAT;

intconstant
    integer .emit OP_PUSH_INT;

boolconstant
    boolean .emit OP_PUSH_BOOL;

optional_space
    .loop single_space;

space
    single_space .and .loop single_space;

single_space
    white_char .or c_style_comment_block .or cpp_style_comment_block;

white_char
    ' ' .or '\t' .or new_line .or '\v' .or '\f';

new_line
    cr_lf .or lf_cr .or '\n' .or '\r';

cr_lf
    '\r' .and '\n';

lf_cr
    '\n' .and '\r';

c_style_comment_block
    '/' .and '*' .and c_style_comment_rest;

c_style_comment_rest
    .loop c_style_comment_char_no_star .and c_style_comment_rest_1;
c_style_comment_rest_1
    c_style_comment_end .or c_style_comment_rest_2;
c_style_comment_rest_2
    '*' .and c_style_comment_rest;

c_style_comment_char_no_star
    '\x2B'-'\xFF' .or '\x01'-'\x29';

c_style_comment_end
    '*' .and '/';

cpp_style_comment_block
    '/' .and '/' .and cpp_style_comment_block_1;
cpp_style_comment_block_1
    cpp_style_comment_block_2 .or cpp_style_comment_block_3;
cpp_style_comment_block_2
    .loop cpp_style_comment_char .and new_line;
cpp_style_comment_block_3
    .loop cpp_style_comment_char;

cpp_style_comment_char
    '\x0E'-'\xFF' .or '\x01'-'\x09' .or '\x0B'-'\x0C';

/* lexical rulez */

/*ampersand
    optional_space .and '&' .and optional_space;*/

ampersandampersand
    optional_space .and '&' .and '&' .and optional_space;

/*ampersandequals
    optional_space .and '&' .and '=' .and optional_space;*/

/*bar
    optional_space .and '|' .and optional_space;*/

barbar
    optional_space .and '|' .and '|' .and optional_space;

/*barequals
    optional_space .and '|' .and '=' .and optional_space;*/

bang
    optional_space .and '!' .and optional_space;

bangequals
    optional_space .and '!' .and '=' .and optional_space;

/*caret
    optional_space .and '^' .and optional_space;*/

caretcaret
    optional_space .and '^' .and '^' .and optional_space;

/*caretequals
    optional_space .and '^' .and '=' .and optional_space;*/

colon
    optional_space .and ':' .and optional_space;

comma
    optional_space .and ',' .and optional_space;

dot
    optional_space .and '.' .and optional_space;

equals
    optional_space .and '=' .and optional_space;

equalsequals
    optional_space .and '=' .and '=' .and optional_space;

greater
    optional_space .and '>' .and optional_space;

greaterequals
    optional_space .and '>' .and '=' .and optional_space;

/*greatergreater
    optional_space .and '>' .and '>' .and optional_space;*/

/*greatergreaterequals
    optional_space .and '>' .and '>' .and '=' .and optional_space;*/

lbrace
    optional_space .and '{' .and optional_space;

lbracket
    optional_space .and '[' .and optional_space;

less
    optional_space .and '<' .and optional_space;

lessequals
    optional_space .and '<' .and '=' .and optional_space;

/*lessless
    optional_space .and '<' .and '<' .and optional_space;*/

/*lesslessequals
    optional_space .and '<' .and '<' .and '=' .and optional_space;*/

lparen
    optional_space .and '(' .and optional_space;

minus
    optional_space .and '-' .and optional_space;

minusequals
    optional_space .and '-' .and '=' .and optional_space;

minusminus
    optional_space .and '-' .and '-' .and optional_space;

/*percent
    optional_space .and '%' .and optional_space;*/

/*percentequals
    optional_space .and '%' .and '=' .and optional_space;*/

plus
    optional_space .and '+' .and optional_space;

plusequals
    optional_space .and '+' .and '=' .and optional_space;

plusplus
    optional_space .and '+' .and '+' .and optional_space;

question
    optional_space .and '?' .and optional_space;

rbrace
    optional_space .and '}' .and optional_space;

rbracket
    optional_space .and ']' .and optional_space;

rparen
    optional_space .and ')' .and optional_space;

semicolon
    optional_space .and ';' .and optional_space;

slash
    optional_space .and '/' .and optional_space;

slashequals
    optional_space .and '/' .and '=' .and optional_space;

star
    optional_space .and '*' .and optional_space;

starequals
    optional_space .and '*' .and '=' .and optional_space;

/*tilde
    optional_space .and '~' .and optional_space;*/

/* string rulez - these are used internally by the parser when parsing quoted strings */

.string string_lexer;

string_lexer
    lex_first_identifier_character .and .loop lex_next_identifier_character;

lex_first_identifier_character
    'a'-'z' .or 'A'-'Z' .or '_';

lex_next_identifier_character
    'a'-'z' .or 'A'-'Z' .or '0'-'9' .or '_';

/* error rulez - these are used by error messages */

err_token
    '~' .or '`' .or '!' .or '@' .or '#' .or '$' .or '%' .or '^' .or '&' .or '*' .or '(' .or ')' .or
    '-' .or '+' .or '=' .or '|' .or '\\' .or '[' .or ']' .or '{' .or '}' .or ':' .or ';' .or '"' .or
    '\'' .or '<' .or ',' .or '>' .or '.' .or '/' .or '?' .or err_identifier;

err_identifier
    id_character_first .and .loop id_character_next;