Grammar railroad diagram

[mingodad]

Using some online tools like https://github.com/GuntherRademacher/rr and https://github.com/GuntherRademacher/ebnf-convert we can have a nice navigable railroad diagram.

Copy and paste the EBNF shown bellow on (IPV4) https://rr.red-dove.com/ui on the tab Edit Grammar the click on the tab View Diagram to see/download a navigable railroad diagram.

I've also added chaos grammar to https://mingodad.github.io/parsertl-playground/playground/ an Yacc/Lex compatible online editor/tester (select Chaos parser from Examples then click Parse to see a parse tree for the content in Input source).

//
// EBNF to be viewd at
//    (IPV6) https://www.bottlecaps.de/rr/ui
//    (IPV4) https://rr.red-dove.com/ui
//
// Copy and paste this at one of the urls shown above in the 'Edit Grammar' tab
// then click the 'View Diagram' tab.
//

parser::=
	  /*%empty*/
	| parser line

line::=
	  T_NEWLINE
	| import
	| stmt

expr::=
	  ident
	| basic_lit
	| binary_expr
	| unary_expr
	| paren_expr
	| incdec_expr
	| index_expr
	| composite_lit
	| call_expr

ident::=
	  T_VAR

basic_lit::=
	  T_TRUE
	| T_FALSE
	| T_INT
	| T_FLOAT
	| T_STRING

binary_expr::=
	  expr T_ADD expr
	| expr T_SUB expr
	| expr T_MUL expr
	| expr T_QUO expr
	| expr T_REM expr
	| expr T_AND expr
	| expr T_OR expr
	| expr T_XOR expr
	| expr T_SHL expr
	| expr T_SHR expr
	| bool_expr

bool_expr::=
	  expr T_EQL expr
	| expr T_NEQ expr
	| expr T_GTR expr
	| expr T_LSS expr
	| expr T_GEQ expr
	| expr T_LEQ expr
	| expr T_LAND expr
	| expr T_LOR expr

unary_expr::=
	  T_ADD expr
	| T_SUB expr
	| T_NOT expr
	| T_TILDE expr

paren_expr::=
	  T_LPAREN expr T_RPAREN

incdec_expr::=
	  T_INC expr
	| expr T_INC
	| T_DEC expr
	| expr T_DEC

alias_expr::=
	  ident
	| ident T_AS ident

alias_expr_list::=
	  alias_expr
	| alias_expr T_COMMA alias_expr_list

index_expr::=
	  expr T_LBRACK expr T_RBRACK

expr_list::=
	  expr
	| expr T_COMMA expr_list
	| expr T_COMMA T_NEWLINE expr_list

key_value_expr::=
	  basic_lit T_COLON expr

key_value_list::=
	  key_value_expr
	| key_value_expr T_COMMA key_value_list
	| key_value_expr T_COMMA T_NEWLINE key_value_list

composite_lit::=
	  T_LBRACK T_RBRACK
	| T_LBRACK expr_list T_RBRACK
	| T_LBRACK T_NEWLINE expr_list T_RBRACK
	| T_LBRACK expr_list T_NEWLINE T_RBRACK
	| T_LBRACK T_NEWLINE expr_list T_NEWLINE T_RBRACK
	| T_LBRACE T_RBRACE
	| T_LBRACE key_value_list T_RBRACE
	| T_LBRACE T_NEWLINE key_value_list T_RBRACE
	| T_LBRACE key_value_list T_NEWLINE T_RBRACE
	| T_LBRACE T_NEWLINE key_value_list T_NEWLINE T_RBRACE

selector_expr::=
	  ident T_PERIOD ident
	| selector_expr T_PERIOD ident

call_expr::=
	  ident T_LPAREN T_RPAREN
	| ident T_LPAREN expr_list T_RPAREN
	| selector_expr T_LPAREN T_RPAREN
	| selector_expr T_LPAREN expr_list T_RPAREN

decision_expr::=
	  bool_expr T_COLON call_expr
	| bool_expr T_COLON return_stmt
	| bool_expr T_COLON break_stmt

default_expr::=
	  T_DEFAULT T_COLON call_expr
	| T_DEFAULT T_COLON return_stmt
	| T_DEFAULT T_COLON break_stmt

decision_expr_list::=
	  decision_expr
	| default_expr
	| decision_expr T_COMMA decision_expr_list
	| decision_expr T_COMMA T_NEWLINE decision_expr_list

stmt::=
	  assign_stmt T_NEWLINE
	| return_stmt T_NEWLINE
	| print_stmt T_NEWLINE
	| echo_stmt T_NEWLINE
	| expr_stmt T_NEWLINE
	| decl_stmt T_NEWLINE
	| del_stmt T_NEWLINE
	| exit_stmt T_NEWLINE
	| function_table_stmt T_NEWLINE

stmt_list::=
	  stmt
	| /*%empty*/
	| stmt stmt_list
	| T_NEWLINE stmt_list

assign_stmt::=
	  expr T_ASSIGN expr

return_stmt::=
	  T_RETURN expr

print_stmt::=
	  T_PRINT expr
	| pretty_spec T_PRINT expr

echo_stmt::=
	  T_ECHO expr
	| pretty_spec T_ECHO expr

expr_stmt::=
	  expr

decl_stmt::=
	  var_decl
	| times_do_decl
	| foreach_as_list_decl
	| foreach_as_dict_decl
	| func_decl

del_stmt::=
	  T_DEL ident
	| T_DEL index_expr

exit_stmt::=
	  T_EXIT
	| T_EXIT expr

function_table_stmt::=
	  T_FUNCTION_TABLE

block_stmt::=
	  stmt_list T_END

break_stmt::=
	  T_BREAK

type_spec::=
	  T_VOID
	| T_VAR_BOOL
	| T_VAR_NUMBER
	| T_VAR_STRING
	| T_VAR_ANY
	| T_VAR_LIST
	| T_VAR_DICT
	| T_VOID sub_type_spec
	| T_VAR_BOOL sub_type_spec
	| T_VAR_NUMBER sub_type_spec
	| T_VAR_STRING sub_type_spec
	| T_VAR_ANY sub_type_spec

sub_type_spec::=
	  T_VAR_LIST
	| T_VAR_DICT
	| T_VAR_LIST sub_type_spec
	| T_VAR_DICT sub_type_spec

pretty_spec::=
	  T_PRETTY

var_decl::=
	  type_spec ident T_ASSIGN expr

func_decl::=
	  func_type block_stmt
	| func_type block_stmt decision_block

times_do_decl::=
	  expr T_TIMES_DO T_ARROW call_expr
	| expr T_TIMES_DO ident T_ARROW call_expr
	| expr T_TIMES_DO T_AS ident T_ARROW call_expr

foreach_as_list_decl::=
	  T_FOREACH expr T_AS ident T_ARROW call_expr
	| T_FOREACH expr T_AS ident T_COMMA ident T_ARROW call_expr

foreach_as_dict_decl::=
	  T_FOREACH expr T_AS ident T_COLON ident T_ARROW call_expr
	| T_FOREACH expr T_AS ident T_COMMA ident T_COLON ident T_ARROW call_expr

import::=
	  T_IMPORT module_selector
	| T_IMPORT module_selector T_AS ident
	| T_FROM module_selector T_IMPORT asterisk_spec
	| T_FROM module_selector T_IMPORT alias_expr_list

module_selector::=
	  ident
	| ident T_PERIOD module_selector
	| ident T_QUO module_selector
	| ident T_BACKSLASH module_selector
	| parent_dir_spec
	| parent_dir_spec T_PERIOD module_selector
	| parent_dir_spec T_QUO module_selector
	| parent_dir_spec T_BACKSLASH module_selector
	| parent_dir_spec module_selector

parent_dir_spec::=
	  T_PERIOD T_PERIOD

asterisk_spec::=
	  T_MUL

field_spec::=
	  type_spec ident

optional_field_spec::=
	  type_spec ident T_ASSIGN expr

field_list_spec::=
	  field_spec
	| field_spec T_COMMA field_list_spec
	| field_spec T_COMMA T_NEWLINE field_list_spec
	| field_spec T_COMMA optional_field_list_spec
	| field_spec T_COMMA T_NEWLINE optional_field_list_spec

optional_field_list_spec::=
	  optional_field_spec
	| optional_field_spec T_COMMA optional_field_list_spec
	| optional_field_spec T_COMMA T_NEWLINE optional_field_list_spec

func_type::=
	  type_spec T_DEF ident T_LPAREN T_RPAREN T_NEWLINE
	| type_spec T_DEF ident T_LPAREN field_list_spec T_RPAREN T_NEWLINE

decision_block::=
	  T_LBRACE decision_expr_list T_RBRACE
	| T_LBRACE T_NEWLINE decision_expr_list T_RBRACE
	| T_LBRACE decision_expr_list T_NEWLINE T_RBRACE
	| T_LBRACE T_NEWLINE decision_expr_list T_NEWLINE T_RBRACE

//Tokens

T_NEWLINE ::= "\n"
T_ASSIGN ::= "="
T_ADD ::= "+"
T_SUB ::= "-"
T_MUL ::= "*"
T_QUO ::= "/"
T_REM ::= "%"
T_BACKSLASH ::= "\\"
T_LPAREN ::= "("
T_RPAREN ::= ")"
T_LBRACK ::= "["
T_RBRACK ::= "]"
T_LBRACE ::= "{"
T_RBRACE ::= "}"
T_COMMA ::= ","
T_PERIOD ::= "."
T_EQL ::= "=="
T_NEQ ::= "!="
T_GTR ::= ">"
T_LSS ::= "<"
T_GEQ ::= ">="
T_LEQ ::= "<="
T_LAND ::= "&&"|"and"
T_LOR ::= "||"|"or"
T_NOT ::= "!"|"not"
T_AND ::= "&"
T_OR ::= "|"
T_XOR ::= "^"
T_TILDE ::= "~"
T_SHL ::= "<<"
T_SHR ::= ">>"
T_INC ::= "++"
T_DEC ::= "--"
T_COLON ::= ":"
T_ARROW ::= "->"
T_EXIT ::= "exit"
T_EXIT ::= "quit"
T_PRINT ::= "print"
T_ECHO ::= "echo"
T_PRETTY ::= "pretty"
T_TRUE ::= "true"
T_FALSE ::= "false"
T_FUNCTION_TABLE ::= "function_table"
T_DEL ::= "del"
T_RETURN ::= "return"
T_DEFAULT ::= "default"

T_TIMES_DO ::= "times"[ \t]+"do"
T_END ::= "end"
T_FOREACH ::= "foreach"
T_AS ::= "as"
T_FROM ::= "from"

T_VAR_BOOL ::= "bool"
T_VAR_NUMBER ::= "num"
T_VAR_STRING ::= "str"
T_VAR_LIST ::= "list"
T_VAR_DICT ::= "dict"
T_VAR_ANY ::= "any"
T_VOID ::= "void"
T_DEF ::= "def"
T_IMPORT ::= "import"
T_BREAK ::= "break"