Grammar railroad diagram

[mingodad]

Using the sql output of the lemon parser generator with the query shown bellow give us an EBNF understood by https://www.bottlecaps.de/rr/ui to generate railroad diagrams.

lemon -S zc-parse.lemon

select name || ' ::=' || group_concat(
	case when hasOr == 1 then ' (' || trim(rtxt) || ')'
	else
		case when length(rtxt) == 0 then ' /* empty */' else rtxt end
	end, '
	|')
from (
	select lhs, name, substr(txt, instr(txt, tbl.sep) + length(tbl.sep)) rtxt, (instr(txt, '|') > 0) hasOr
	from rule left join symbol on lhs=id, (select '::=' as sep) tbl
) as t
group by lhs;

We can see a railroad diagram for the grammar in src/common/scripting/frontend/zcc-parse.lemon , copy and paste the EBNF shown bellow on https://www.bottlecaps.de/rr/ui in the tab Edit Grammar then switching to the tab View Diagram.

It can be made nicer if we add the tokens to it, see zephir-lang/php-zephir-parser#106

declarator ::= decl_flags type_list_or_void variables_or_function
opt_func_body ::= SEMICOLON
    | function_body
function_body ::= compound_statement
main ::= translation_unit
translation_unit ::= /* empty */
    | translation_unit external_declaration
    | error
    | translation_unit EOF
external_declaration ::= mixin_definition
    | class_definition
    | struct_def
    | enum_def
    | const_def
    | include_def
mixin_definition ::= mixin_class_definition
class_definition ::= class_head class_body
struct_def ::= STRUCT IDENTIFIER struct_flags LBRACE opt_struct_body RBRACE opt_semicolon
    | EXTEND STRUCT IDENTIFIER LBRACE opt_struct_body RBRACE opt_semicolon
enum_def ::= ENUM IDENTIFIER enum_type LBRACE opt_enum_list RBRACE opt_semicolon
const_def ::= CONST IDENTIFIER EQ expr SEMICOLON
include_def ::= INCLUDE string_constant
opt_semicolon ::= /* empty */
    | SEMICOLON
opt_comma ::= /* empty */
    | COMMA
opt_expr ::= /* empty */
    | expr
expr ::= expr ADD expr
    | expr SUB expr
    | expr MUL expr
    | expr DIV expr
    | expr MOD expr
    | expr POW expr
    | expr CROSSPROD expr
    | expr DOTPROD expr
    | expr LSH expr
    | expr RSH expr
    | expr URSH expr
    | expr DOTDOT expr
    | expr LT expr
    | expr GT expr
    | expr LTEQ expr
    | expr GTEQ expr
    | expr LTGTEQ expr
    | expr IS expr
    | expr EQEQ expr
    | expr NEQ expr
    | expr APPROXEQ expr
    | expr AND expr
    | expr XOR expr
    | expr OR expr
    | expr ANDAND expr
    | expr OROR expr
    | expr EQ expr
    | expr ADDEQ expr
    | expr SUBEQ expr
    | expr MULEQ expr
    | expr DIVEQ expr
    | expr MODEQ expr
    | expr LSHEQ expr
    | expr RSHEQ expr
    | expr URSHEQ expr
    | expr ANDEQ expr
    | expr OREQ expr
    | expr XOREQ expr
    | expr SCOPE expr
    | expr QUESTION expr COLON expr
    | unary_expr
string_constant ::= STRCONST
    | string_constant STRCONST
class_head ::= EXTEND CLASS IDENTIFIER
    | CLASS IDENTIFIER class_ancestry class_flags
class_innards ::= /* empty */
    | class_innards class_member
class_member ::= declarator
    | mixin_statement
    | enum_def
    | struct_def
    | states_def
    | default_def
    | const_def
    | property_def
    | flag_def
    | staticarray_statement
class_body ::= SEMICOLON class_innards EOF
    | LBRACE class_innards RBRACE
class_ancestry ::= /* empty */
    | COLON dottable_id
class_flags ::= /* empty */
    | class_flags ABSTRACT
    | class_flags NATIVE
    | class_flags UI
    | class_flags PLAY
    | class_flags REPLACES dottable_id
    | class_flags VERSION LPAREN STRCONST RPAREN
dottable_id ::= IDENTIFIER
    | dottable_id DOT IDENTIFIER
    | dottable_id DOT DEFAULT
    | dottable_id DOT COLOR
mixin_statement ::= MIXIN IDENTIFIER SEMICOLON
property_def ::= PROPERTY IDENTIFIER COLON identifier_list SEMICOLON
flag_def ::= FLAGDEF IDENTIFIER COLON IDENTIFIER COMMA INTCONST SEMICOLON
states_def ::= STATES states_opts scanner_mode LBRACE states_body RBRACE
default_def ::= DEFAULT LBRACE RBRACE
    | DEFAULT LBRACE default_statement_list RBRACE
    | DEFAULT LBRACE error RBRACE
staticarray_statement ::= STATICCONST type IDENTIFIER LBRACKET RBRACKET EQ LBRACE expr_list RBRACE SEMICOLON
    | STATICCONST type LBRACKET RBRACKET IDENTIFIER EQ LBRACE expr_list RBRACE SEMICOLON
opt_struct_body ::= /* empty */
    | error
    | struct_body
struct_body ::= struct_body struct_member
    | struct_member
struct_member ::= declarator
    | enum_def
    | const_def
    | staticarray_statement
identifier_list ::= IDENTIFIER
    | states_opt COMMA IDENTIFIER
states_opt ::= IDENTIFIER
    | states_opt COMMA IDENTIFIER
struct_flags ::= /* empty */
    | struct_flags UI
    | struct_flags PLAY
    | struct_flags CLEARSCOPE
    | struct_flags NATIVE
    | struct_flags VERSION LPAREN STRCONST RPAREN
enum_list ::= error
    | enum_list COMMA enumerator
    | enumerator
opt_enum_list ::= /* empty */
    | enum_list opt_comma
enumerator ::= IDENTIFIER
    | IDENTIFIER EQ expr
enum_type ::= /* empty */
    | COLON int_type
int_type ::= SBYTE
    | BYTE
    | SHORT
    | USHORT
    | INT
    | UINT
mixin_class_definition ::= MIXIN CLASS IDENTIFIER LBRACE mixin_class_body RBRACE
mixin_class_body ::= /* empty */
    | mixin_class_body mixin_class_member
mixin_class_member ::= declarator
    | enum_def
    | struct_def
    | states_def
    | default_def
    | const_def
    | property_def
    | flag_def
    | staticarray_statement
states_body ::= /* empty */
    | error
    | states_body state_line
    | states_body state_label
    | states_body state_flow
state_line ::= NWS NWS expr state_opts state_action
state_label ::= NWS COLON
state_flow ::= state_flow_type scanner_mode SEMICOLON
state_flow_type ::= STOP
    | WAIT
    | FAIL
    | LOOP
    | GOTO dottable_id state_goto_offset
    | GOTO IDENTIFIER SCOPE dottable_id state_goto_offset
    | GOTO SUPER SCOPE dottable_id state_goto_offset
state_goto_offset ::= /* empty */
    | ADD expr
state_action ::= LBRACE statement_list scanner_mode RBRACE
    | LBRACE scanner_mode RBRACE
    | LBRACE error scanner_mode RBRACE
    | state_call scanner_mode SEMICOLON
state_call ::= /* empty */
    | IDENTIFIER state_call_params
state_call_params ::= /* empty */
    | LPAREN func_expr_list RPAREN
state_opts ::= /* empty */
    | state_opts BRIGHT
    | state_opts FAST
    | state_opts SLOW
    | state_opts NODELAY
    | state_opts CANRAISE
    | state_opts OFFSET LPAREN expr COMMA expr RPAREN
    | state_opts LIGHT LPAREN light_list RPAREN
states_opts ::= /* empty */
    | LPAREN states_opt RPAREN
scanner_mode ::= /* empty */
light_list ::= STRCONST
    | light_list COMMA STRCONST
statement_list ::= statement
    | statement_list statement
func_expr_list ::= func_expr_list COMMA func_expr_item
    | func_expr_item
default_statement_list ::= default_statement
    | default_statement_list default_statement
default_statement ::= SEMICOLON
    | error SEMICOLON
    | property_statement
    | flag_statement
property_statement ::= dottable_id expr_list SEMICOLON
    | dottable_id SEMICOLON
flag_statement ::= ADD dottable_id
    | SUB dottable_id
expr_list ::= expr_list COMMA expr
    | expr
type_name ::= type_name1
    | IDENTIFIER
    | ATSIGN IDENTIFIER
    | READONLY LT IDENTIFIER GT
    | READONLY LT ATSIGN IDENTIFIER GT
    | DOT dottable_id
type_name1 ::= BOOL
    | FLOAT
    | DOUBLE
    | VECTOR2
    | VECTOR3
    | NAME
    | SOUND
    | STATE
    | COLOR
    | LET
    | int_type
aggregate_type ::= MAP LT type_or_array COMMA type_or_array GT
    | ARRAY LT type_or_array GT
    | CLASS class_restrictor
type ::= type_name
    | aggregate_type
type_list ::= type_list COMMA type_or_array
    | type_or_array
type_list_or_void ::= VOID
    | type_list
type_or_array ::= type array_size
    | type
class_restrictor ::= /* empty */
    | LT dottable_id GT
array_size ::= array_size array_size_expr
    | array_size_expr
array_size_expr ::= LBRACKET opt_expr RBRACKET
variables_or_function ::= IDENTIFIER LPAREN func_params RPAREN func_const opt_func_body
    | variable_list SEMICOLON
    | error SEMICOLON
decl_flags ::= /* empty */
    | decl_flags decl_flag
    | decl_flags ACTION states_opts
    | decl_flags DEPRECATED LPAREN STRCONST opt_deprecation_message RPAREN
    | decl_flags VERSION LPAREN STRCONST RPAREN
func_params ::= /* empty */
    | VOID
    | func_param_list COMMA ELLIPSIS
    | func_param_list
func_const ::= /* empty */
    | CONST
variable_list ::= variable_list COMMA variable_name
    | variable_name
variable_name ::= IDENTIFIER
    | IDENTIFIER array_size
decl_flag ::= NATIVE
    | STATIC
    | PRIVATE
    | PROTECTED
    | LATENT
    | FINAL
    | META
    | TRANSIENT
    | READONLY
    | INTERNAL
    | VIRTUAL
    | OVERRIDE
    | ABSTRACT
    | VARARG
    | UI
    | PLAY
    | CLEARSCOPE
    | VIRTUALSCOPE
opt_deprecation_message ::= /* empty */
    | COMMA STRCONST
func_param_list ::= func_param_list COMMA func_param
    | func_param
func_param ::= func_param_flags type IDENTIFIER
    | func_param_flags type IDENTIFIER EQ expr
func_param_flags ::= /* empty */
    | func_param_flags IN
    | func_param_flags OUT
    | func_param_flags OPTIONAL
primary ::= IDENTIFIER
    | SUPER
    | constant
    | LPAREN expr COMMA expr COMMA expr RPAREN
    | LPAREN expr COMMA expr RPAREN
    | LPAREN expr RPAREN
    | primary LPAREN func_expr_list RPAREN
    | LPAREN CLASS LT IDENTIFIER GT RPAREN LPAREN func_expr_list RPAREN
    | primary LBRACKET expr RBRACKET
    | primary DOT IDENTIFIER
    | primary ADDADD
    | primary SUBSUB
    | LPAREN error RPAREN
unary_expr ::= SUB unary_expr
    | ADD unary_expr
    | SUBSUB unary_expr
    | ADDADD unary_expr
    | TILDE unary_expr
    | BANG unary_expr
    | SIZEOF unary_expr
    | ALIGNOF unary_expr
    | primary
constant ::= INTCONST
    | UINTCONST
    | FLOATCONST
    | NAMECONST
    | FALSE
    | TRUE
    | NULLPTR
    | string_constant
func_expr_item ::= /* empty */
    | named_expr
named_expr ::= IDENTIFIER COLON expr
    | expr
compound_statement ::= LBRACE RBRACE
    | LBRACE statement_list RBRACE
    | LBRACE error RBRACE
statement ::= SEMICOLON
    | labeled_statement
    | compound_statement
    | expression_statement SEMICOLON
    | assign_statement SEMICOLON
    | local_var SEMICOLON
    | error SEMICOLON
    | staticarray_statement
    | selection_statement
    | iteration_statement
    | jump_statement
labeled_statement ::= CASE expr COLON
    | DEFAULT COLON
expression_statement ::= expr
selection_statement ::= if_front
    | if_front ELSE statement
    | SWITCH LPAREN expr RPAREN statement
iteration_statement ::= while_or_until LPAREN expr RPAREN statement
    | DO statement while_or_until LPAREN expr RPAREN
    | FOR LPAREN for_init SEMICOLON opt_expr SEMICOLON for_bump RPAREN statement
jump_statement ::= CONTINUE SEMICOLON
    | BREAK SEMICOLON
    | RETURN SEMICOLON
    | RETURN expr_list SEMICOLON
assign_statement ::= LBRACKET expr_list RBRACKET EQ expr
local_var ::= type variable_list_with_init
while_or_until ::= WHILE
    | UNTIL
for_init ::= local_var
    | for_bump
for_bump ::= /* empty */
    | expression_statement
    | for_bump COMMA expression_statement
if_front ::= IF LPAREN expr RPAREN statement
variable_list_with_init ::= variable_list_with_init COMMA var_init
    | var_init
var_init ::= IDENTIFIER
    | IDENTIFIER array_size
    | IDENTIFIER EQ expr
    | IDENTIFIER EQ LBRACE expr_list RBRACE
    | IDENTIFIER array_size EQ LBRACE expr_list RBRACE
    | IDENTIFIER EQ LBRACE error RBRACE

[coelckers]

This needs to be implemented by someone with a bit more knowledge about the subject matter.

[coelckers]

I don't think this needs to be kept open, considering it got no response in half a year.