Grammar railroad diagram

[mingodad]

I've done a experimental tool to convert bison grammars to a kind of EBNF understood by https://www.bottlecaps.de/rr/ui to generate railroad diagrams see bellow the converted src/3d/ocaml/parser.mly and with some hand made changes to allow view it at https://www.bottlecaps.de/rr/ui the order of the rules could be changed to a better view of the railroad diagrams. Copy and paste the EBNF bellow on https://www.bottlecaps.de/rr/ui tab Edit Grammar then switch to the tab View Diagram.

/*
From https://raw.githubusercontent.com/project-everest/everparse/master/src/3d/ocaml/parser.mly
*/

option_of ::=  /* empty */ | X
right_flexible_list ::=  /* empty */ | X | X SEP right_flexible_list
right_flexible_nonempty_list ::=  X | X SEP right_flexible_list
constant ::=  INT | XINT | BOOL
rel_op ::=  DOUBLEEQ | NEQ | LEQ | LESS_THAN | GEQ | GREATER_THAN
else_opt ::=  /* empty */ | ELSE LBRACE expr RBRACE
atomic_expr ::=  qident | THIS | constant
atomic_or_paren_expr ::=  atomic_expr | LPAREN expr RPAREN
castable_expr ::=  /* empty */ | atomic_expr | LPAREN expr RPAREN
expr_no_range ::=  atomic_expr | LPAREN expr RPAREN castable_expr | expr rel_op expr | expr AND expr | expr OR expr | expr MINUS expr | expr PLUS expr | expr STAR expr | expr DIV expr | expr REM expr | expr BITWISE_AND expr | expr BITWISE_XOR expr | expr BITWISE_OR expr | BITWISE_NOT expr | expr SHIFT_RIGHT expr | expr SHIFT_LEFT expr | NOT expr | SIZEOF LPAREN expr RPAREN | atomic_or_paren_expr QUESTION atomic_or_paren_expr COLON atomic_or_paren_expr | IF expr LBRACE expr RBRACE else_opt | IDENT LPAREN arguments RPAREN
expr ::=  expr_no_range
arguments ::=  right_flexible_nonempty_list
qident ::=  IDENT | IDENT DOT IDENT
typ_no_range ::=  qident | qident LPAREN arguments RPAREN
typ ::=  typ_no_range
maybe_pointer_typ ::=  typ | pointer_typ
pointer_typ ::=  maybe_pointer_typ STAR
refinement ::=  LBRACE expr RBRACE
array_size ::=  LBRACK expr RBRACK | LBRACK_BYTESIZE expr RBRACK | LBRACK_LEQ expr RBRACK | LBRACK_BYTESIZE_AT_MOST expr RBRACK | LBRACK_EQ expr RBRACK | LBRACK_SINGLE_ELEMENT_BYTESIZE expr RBRACK
array_annot ::=  /* empty */ | array_size | LBRACK_STRING RBRACK | LBRACK_STRING_AT_MOST expr RBRACK
bitwidth ::=  COLON INT
field_action ::=  LBRACE_ONSUCCESS action RBRACE
struct_field ::=  typ IDENT option_of array_annot option_of option_of
field ::=  struct_field
immutable_parameter ::=  typ IDENT
mutable_parameter ::=  MUTABLE pointer_typ IDENT
parameter ::=  immutable_parameter | mutable_parameter
parameters ::=  /* empty */ | LPAREN right_flexible_nonempty_list RPAREN
case_pattern ::=  qident | constant
case ::=  CASE case_pattern COLON field | DEFAULT COLON field
cases ::=  right_flexible_nonempty_list
attribute ::=  ENTRYPOINT | ALIGNED
attributes ::=  /* empty */ | attribute attributes
where_opt ::=  /* empty */ | WHERE expr | REQUIRES expr
atomic_action ::=  RETURN expr SEMICOLON | ABORT SEMICOLON | FIELD_POS SEMICOLON | FIELD_PTR SEMICOLON | STAR IDENT SEMICOLON | STAR IDENT EQ expr SEMICOLON | IDENT LPAREN arguments RPAREN SEMICOLON
action_else ::=  ELSE LBRACE action RBRACE
action_no_range ::=  atomic_action | atomic_action action | IF expr LBRACE action RBRACE option_of | VAR IDENT EQ atomic_action action
action ::=  action_no_range
enum_case ::=  IDENT | IDENT EQ INT | IDENT EQ IDENT
exported ::=  /* empty */ | EXPORT
maybe_semi ::=  /* empty */ | SEMICOLON
typedef_pointer_name_opt ::=  /* empty */ | COMMA STAR IDENT
decl_no_range ::=  MODULE IDENT EQ IDENT | DEFINE IDENT constant | IDENT ENUM IDENT LBRACE right_flexible_nonempty_list RBRACE maybe_semi | attributes TYPEDEF typ IDENT SEMICOLON | attributes TYPEDEF STRUCT IDENT parameters where_opt LBRACE right_flexible_nonempty_list RBRACE IDENT typedef_pointer_name_opt SEMICOLON | attributes CASETYPE IDENT parameters LBRACE SWITCH LPAREN IDENT RPAREN LBRACE cases RBRACE RBRACE IDENT typedef_pointer_name_opt SEMICOLON
block_comment_opt ::=  /* empty */ | BLOCK_COMMENT
decl ::=  block_comment_opt exported decl_no_range
expr_top ::=  expr EOF
type_map ::=  IDENT | IDENT AS IDENT
type_refinement ::=  REFINING right_flexible_nonempty_list LBRACE right_flexible_nonempty_list RBRACE
prog ::=  decl option_of EOF | decl prog

// Tokens

WHERE ::= "where"
REQUIRES ::= "requires"
SIZEOF ::= "sizeof"
ENUM ::= "enum"
TYPEDEF ::= "typedef"
STRUCT ::= "struct"
CASETYPE ::= "casetype"
SWITCH ::= "switch"
CASE ::= "case"
DEFAULT ::= "default"
THIS ::= "this"
ENTRYPOINT ::= "entrypoint"
ALIGNED ::= "aligned"
IF ::= "if"
ELSE ::= "else"
MUTABLE ::= "mutable"
FIELD_POS ::= "field_pos"
FIELD_PTR ::= "field_ptr"
VAR ::= "var"
ABORT ::= "abort"
RETURN ::= "return"
REFINING ::= "refining"
AS ::= "as"
MODULE ::= "module"
EXPOR ::= "export"

DEFINE ::= "#define"
LPAREN ::= "("
RPAREN ::= ")"
SHIFT_LEFT ::= "<<"
SHIFT_RIGHT ::= ">>"
GEQ ::= ">="
LEQ ::= "<="
GREATER_THAN ::= ">"
LESS_THAN ::= "<"
DOUBLEEQ ::= "=="
EQ ::= "="
NEQ ::= "!="
NOT ::= "!"
AND ::= "&&"
BITWISE_AND ::= "&"
OR ::= "||"
BITWISE_OR ::= "|"
BITWISE_XOR ::= "^"
BITWISE_NOT ::= "~"
DOT ::= "."
COMMA ::= ","
SEMICOLON ::= ";"
COLON ::= ":"
QUESTION ::= "?"
LBRACE_ONSUCCESS ::= "{:on-success"
LBRACE ::= "{"
RBRACE ::= "}"
LBRACK_BYTESIZE ::= "[:byte-size"
LBRACK_BYTESIZE_AT_MOST ::= "[:byte-size-single-element-array-at-most"
LBRACK_SINGLE_ELEMENT_BYTESIZE ::= "[:byte-size-single-element-array"
LBRACK_STRING ::= "[:zeroterm"
LBRACK_STRING_AT_MOST ::= "[:zeroterm-byte-size-at-most"
LBRACK ::= "["
RBRACK ::= "]"
LBRACK_EQ ::= "[="
LBRACK_LEQ ::= "[<="
STAR ::= "*"
DIV ::= "/"
REM ::= "%"
PLUS ::= "+"
MINUS ::= "-"