一个GLSL Shader的格式化算法(LALR解析器)

#extractor <GLSL4.60.8.st.ext>

translation_unit :
      external_declaration
    | translation_unit external_declaration
 ;
external_declaration :
      function_definition
    | declaration
    | ';'
 ;
function_definition :
      function_prototype compound_statement/* compound_statement_no_new_scope */
 ;
variable_identifier :
      'identifier'
 ;
primary_expression :
      variable_identifier
    | 'intConstant'
    | 'uintConstant'
    | 'floatConstant'
    | 'boolConstant'
    | 'doubleConstant'
    | '(' expression ')'
 ;
postfix_expression :
      primary_expression
    | postfix_expression '[' integer_expression ']'
    | function_call
    | postfix_expression '.' 'identifier' // FIELD_SELECTION
    | postfix_expression '++'
    | postfix_expression '--'
 ;
integer_expression :
      expression
 ;
function_call :
      function_call_or_method
 ;
function_call_or_method :
      function_call_generic
 ;
function_call_generic :
      function_call_header_with_parameters ')'
    | function_call_header_no_parameters ')'
 ;
function_call_header_no_parameters :
      function_call_header 'void'
    | function_call_header
 ;
function_call_header_with_parameters :
      function_call_header assignment_expression
    | function_call_header_with_parameters ',' assignment_expression
 ;
function_call_header :
      function_identifier '('
 ;
function_identifier :
      type_specifier
    | postfix_expression
 ;
unary_expression :
      postfix_expression
    | '++' unary_expression
    | '--' unary_expression
    | unary_operator unary_expression
 ;
unary_operator :
      '+'
    | '-'
    | '!'
    | '~'
 ;
multiplicative_expression :
      unary_expression
    | multiplicative_expression '*' unary_expression
    | multiplicative_expression '/' unary_expression
    | multiplicative_expression '%' unary_expression
 ;
additive_expression :
      multiplicative_expression
    | additive_expression '+' multiplicative_expression
    | additive_expression '-' multiplicative_expression
 ;
shift_expression :
      additive_expression
    | shift_expression '<<' additive_expression
    | shift_expression '>>' additive_expression
 ;
relational_expression :
      shift_expression
    | relational_expression '<' shift_expression
    | relational_expression '>' shift_expression
    | relational_expression '<=' shift_expression
    | relational_expression '>=' shift_expression
 ;
equality_expression :
      relational_expression
    | equality_expression '==' relational_expression
    | equality_expression '!=' relational_expression
 ;
and_expression :
      equality_expression
    | and_expression '&' equality_expression
 ;
exclusive_or_expression :
      and_expression
    | exclusive_or_expression '^' and_expression
 ;
inclusive_or_expression :
      exclusive_or_expression
    | inclusive_or_expression '|' exclusive_or_expression
 ;
logical_and_expression :
      inclusive_or_expression
    | logical_and_expression '&&' inclusive_or_expression
 ;
logical_xor_expression :
      logical_and_expression
    | logical_xor_expression '^^' logical_and_expression
 ;
logical_or_expression :
      logical_xor_expression
    | logical_or_expression '||' logical_xor_expression
 ;
conditional_expression :
      logical_or_expression
    | logical_or_expression '?' expression ':' assignment_expression
 ;
assignment_expression :
      conditional_expression
    | unary_expression assignment_operator assignment_expression
 ;
assignment_operator :
      '='
    | '*='
    | '/='
    | '%='
    | '+='
    | '-='
    | '<<='
    | '>>='
    | '&='
    | '^='
    | '|='
 ;
expression :
      assignment_expression
    | expression ',' assignment_expression
 ;
constant_expression :
      conditional_expression
 ;
declaration :
      function_prototype ';'
    | init_declarator_list ';'
    | 'precision' precision_qualifier type_specifier ';'
    | type_qualifier 'identifier' '{' struct_declaration_list '}' ';'
    | type_qualifier 'identifier' '{' struct_declaration_list '}' 'identifier' ';'
    | type_qualifier 'identifier' '{' struct_declaration_list '}' 'identifier' array_specifier ';'
    | type_qualifier ';'
    | type_qualifier 'identifier' ';'
    | type_qualifier 'identifier' identifier_list ';'
 ;
identifier_list :
      ',' 'identifier'
    | identifier_list ',' 'identifier'
 ;
function_prototype :
      function_declarator ')'
 ;
function_declarator :
      function_header
    | function_header_with_parameters
 ;
function_header_with_parameters :
      function_header parameter_declaration
    | function_header_with_parameters ',' parameter_declaration
 ;
function_header :
      fully_specified_type 'identifier' '('
 ;
parameter_declarator :
      type_specifier 'identifier'
    | type_specifier 'identifier' array_specifier
 ;
parameter_declaration :
      type_qualifier parameter_declarator
    | parameter_declarator
    | type_qualifier parameter_type_specifier
    | parameter_type_specifier
 ;
parameter_type_specifier :
      type_specifier
 ;
init_declarator_list :
      single_declaration
    | init_declarator_list ',' 'identifier'
    | init_declarator_list ',' 'identifier' array_specifier
    | init_declarator_list ',' 'identifier' array_specifier '=' initializer
    | init_declarator_list ',' 'identifier' '=' initializer
 ;
single_declaration :
      fully_specified_type
    | fully_specified_type 'identifier'
    | fully_specified_type 'identifier' array_specifier
    | fully_specified_type 'identifier' array_specifier '=' initializer
    | fully_specified_type 'identifier' '=' initializer
 ;
fully_specified_type :
      type_specifier
    | type_qualifier type_specifier
 ;
invariant_qualifier :
      'invariant'
 ;
interpolation_qualifier :
      'smooth'
    | 'flat'
    | 'noperspective'
 ;
layout_qualifier :
      'layout' '(' layout_qualifier_id_list ')'
 ;
layout_qualifier_id_list :
      layout_qualifier_id
    | layout_qualifier_id_list ',' layout_qualifier_id
 ;
layout_qualifier_id :
      'identifier'
    | 'identifier' '=' constant_expression
    | 'shared'
 ;
precise_qualifier :
      'precise'
 ;
type_qualifier :
      single_type_qualifier
    | type_qualifier single_type_qualifier
 ;
single_type_qualifier :
      storage_qualifier
    | layout_qualifier
    | precision_qualifier
    | interpolation_qualifier
    | invariant_qualifier
    | precise_qualifier
 ;
storage_qualifier :
      'const'
    | 'in'
    | 'out'
    | 'inout'
    | 'centroid'
    | 'patch'
    | 'sample'
    | 'uniform'
    | 'buffer'
    | 'shared'
    | 'coherent'
    | 'volatile'
    | 'restrict'
    | 'readonly'
    | 'writeonly'
    | 'subroutine'
    | 'subroutine' '(' type_name_list ')'
 ;
type_name_list :
      'type_name'
    | type_name_list ',' 'type_name'
 ;
type_specifier :
      type_specifier_nonarray
    | type_specifier_nonarray array_specifier
 ;
array_specifier :
      '[' ']'
    | '[' conditional_expression ']'
    | array_specifier '[' ']'
    | array_specifier '[' conditional_expression ']'
 ;
type_specifier_nonarray :
      'void'
    | 'float'
    | 'double'
    | 'int'
    | 'uint'
    | 'bool'
    | 'vec2'
    | 'vec3'
    | 'vec4'
    | 'dvec2'
    | 'dvec3'
    | 'dvec4'
    | 'bvec2'
    | 'bvec3'
    | 'bvec4'
    | 'ivec2'
    | 'ivec3'
    | 'ivec4'
    | 'uvec2'
    | 'uvec3'
    | 'uvec4'
    | 'mat2'
    | 'mat3'
    | 'mat4'
    | 'mat2x2'
    | 'mat2x3'
    | 'mat2x4'
    | 'mat3x2'
    | 'mat3x3'
    | 'mat3x4'
    | 'mat4x2'
    | 'mat4x3'
    | 'mat4x4'
    | 'dmat2'
    | 'dmat3'
    | 'dmat4'
    | 'dmat2x2'
    | 'dmat2x3'
    | 'dmat2x4'
    | 'dmat3x2'
    | 'dmat3x3'
    | 'dmat3x4'
    | 'dmat4x2'
    | 'dmat4x3'
    | 'dmat4x4'
    | 'atomic_uint'
    | 'sampler2D'
    | 'sampler3D'
    | 'samplerCube'
    | 'sampler2DShadow'
    | 'samplerCubeShadow'
    | 'sampler2DArray'
    | 'sampler2DArrayShadow'
    | 'samplerCubeArray'
    | 'samplerCubeArrayShadow'
    | 'isampler2D'
    | 'isampler3D'
    | 'isamplerCube'
    | 'isampler2DArray'
    | 'isamplerCubeArray'
    | 'usampler2D'
    | 'usampler3D'
    | 'usamplerCube'
    | 'usampler2DArray'
    | 'usamplerCubeArray'
    | 'sampler1D'
    | 'sampler1DShadow'
    | 'sampler1DArray'
    | 'sampler1DArrayShadow'
    | 'isampler1D'
    | 'isampler1DArray'
    | 'usampler1D'
    | 'usampler1DArray'
    | 'sampler2DRect'
    | 'sampler2DRectShadow'
    | 'isampler2DRect'
    | 'usampler2DRect'
    | 'samplerBuffer'
    | 'isamplerBuffer'
    | 'usamplerBuffer'
    | 'sampler2DMS'
    | 'isampler2DMS'
    | 'usampler2DMS'
    | 'sampler2DMSArray'
    | 'isampler2DMSArray'
    | 'usampler2DMSArray'
    | 'image2D'
    | 'iimage2D'
    | 'uimage2D'
    | 'image3D'
    | 'iimage3D'
    | 'uimage3D'
    | 'imageCube'
    | 'iimageCube'
    | 'uimageCube'
    | 'imageBuffer'
    | 'iimageBuffer'
    | 'uimageBuffer'
    | 'image1D'
    | 'iimage1D'
    | 'uimage1D'
    | 'image1DArray'
    | 'iimage1DArray'
    | 'uimage1DArray'
    | 'image2DRect'
    | 'iimage2DRect'
    | 'uimage2DRect'
    | 'image2DArray'
    | 'iimage2DArray'
    | 'uimage2DArray'
    | 'imageCubeArray'
    | 'iimageCubeArray'
    | 'uimageCubeArray'
    | 'image2DMS'
    | 'iimage2DMS'
    | 'uimage2DMS'
    | 'image2DMSArray'
    | 'iimage2DMSArray'
    | 'uimage2DMSArray'
    | struct_specifier
    | 'type_name'
 ;
precision_qualifier :
      'highp'
    | 'mediump'
    | 'lowp'
 ;
struct_specifier :
      'struct' 'type_name'/* 'identifier' */ '{' struct_declaration_list '}'
    | 'struct' '{' struct_declaration_list '}'
 ;
struct_declaration_list :
      struct_declaration
    | struct_declaration_list struct_declaration
 ;
struct_declaration :
      type_specifier struct_declarator_list ';'
    | type_qualifier type_specifier struct_declarator_list ';'
 ;
struct_declarator_list :
      struct_declarator
    | struct_declarator_list ',' struct_declarator
 ;
struct_declarator :
      'identifier'
    | 'identifier' array_specifier
 ;
initializer :
      assignment_expression
    | '{' initializer_list '}'
    | '{' initializer_list ',' '}'
 ;
initializer_list :
      initializer
    | initializer_list ',' initializer
 ;
declaration_statement :
      declaration
 ;
statement :
      compound_statement
    | simple_statement
 ;
simple_statement :
      declaration_statement
    | expression_statement
    | selection_statement
    | switch_statement
    | case_label
    | iteration_statement
    | jump_statement
 ;
compound_statement :
      '{' '}'
    | '{' statement_list '}'
 ;
 /* merge into statement
statement_no_new_scope :
      compound_statement_no_new_scope
    | simple_statement
 ;
 */
 /* merge into compound_statement
compound_statement_no_new_scope :
      '{' '}'
    | '{' statement_list '}'
 ;
 */
statement_list :
      statement
    | statement_list statement
 ;
expression_statement :
      ';'
    | expression ';'
 ;
selection_statement :
      'if' '(' expression ')' selection_rest_statement
 ;
selection_rest_statement :
      statement 'else' statement
    | statement
 ;
condition :
      expression
    | fully_specified_type 'identifier' '=' initializer
 ;
switch_statement :
      'switch' '(' expression ')' '{' switch_statement_list '}'
 ;
switch_statement_list :
      empty
    | statement_list
 ;
case_label :
      'case' expression ':'
    | 'default' ':'
 ;
iteration_statement :
      'while' '(' condition ')' statement/* statement_no_new_scope */
    | 'do' statement 'while' '(' expression ')' ';'
    | 'for' '(' for_init_statement for_rest_statement ')' statement/* statement_no_new_scope */
 ;
for_init_statement :
      expression_statement
    | declaration_statement
 ;
conditionopt :
      condition
    | empty
 ;
for_rest_statement :
      conditionopt ';'
    | conditionopt ';' expression
 ;
jump_statement :
      'continue' ';'
    | 'break' ';'
    | 'return' ';'
    | 'return' expression ';'
    | 'discard' ';'
 ;


// lexical statements

// no need : 'struct' 'identifier' '{' struct_declaration_list '}'
// now I changed it into 'struct' 'type_name' '{' struct_declaration_list '}'
// only identifier next to 'struct' is a user-defined type and should be a 'type_name' token.
'type_name' %%<'struct'>[a-zA-Z_][a-zA-Z0-9_]*%%


'intConstant' %%[-+]?[0-9]+%%
'intConstant' %%0x[0-9A-Fa-f]+%%
'uintConstant' %%[-+]?[0-9]+[uU]%%
'uintConstant' %%0x[0-9A-Fa-f]+[uU]%%
'floatConstant' %%[-+]?[0-9]+([.][0-9]+)?([Ee][-+]?[0-9]+)?[fF]%%
'boolConstant' %%true/[^a-zA-Z0-9_]%%
'boolConstant' %%false/[^a-zA-Z0-9_]%%
'doubleConstant' %%[-+]?[0-9]+([.][0-9]+)?([Ee][-+]?[0-9]+)?%%


'identifier' %%[a-zA-Z_][a-zA-Z0-9_]*%%


%grammarName   GLSL
%blockComment  on
%inlineComment on