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"