Grammar railroad diagram

[mingodad]

Using some online tools like https://www.bottlecaps.de/rr/ui and https://www.bottlecaps.de/convert/ we can have a nice navigable railroad diagram.

Copy and paste the EBNF shown bellow on https://www.bottlecaps.de/rr/ui on the tab Edit Grammar the click on the tab View Diagram to see/download a navigable railroad diagram.

/* converted on Wed Feb 8, 2023, 11:55 (UTC+01) by bison-to-w3c v0.62 which is Copyright (c) 2011-2022 by Gunther Rademacher <grd@gmx.net> */

start    ::= KW_MODULE UIDENT '=' autoload ( ( KW_LET LIDENT param_list | KW_LET_REC LIDENT ) '=' exp | KW_TEST test_exp '=' ( exp | test_special_res ) )*
autoload ::= ( KW_AUTOLOAD LIDENT )?
test_exp ::= aexp ( KW_GET | KW_PUT aexp KW_AFTER ) exp
test_special_res
         ::= '?'
           | '*'
exp      ::= KW_LET LIDENT param_list '=' exp KW_IN exp
           | unionexp ( ';' unionexp )*
unionexp ::= ( minusexp | ( '{' tree_branch '}' )+ ) ( '|' minusexp )*
minusexp ::= catexp ( '-' catexp )*
catexp   ::= appexp ( '.' appexp )*
appexp   ::= rexp+
aexp     ::= qid
           | DQUOTED
           | REGEXP
           | '(' exp? ')'
           | '[' exp ']'
rexp     ::= aexp rep?
rep      ::= '*'
           | '+'
           | '?'
qid      ::= LIDENT
           | QIDENT
           | KW_GET
           | KW_PUT
param_list
         ::= param*
param    ::= '(' id ':' type ')'
id       ::= LIDENT
           | KW_GET
           | KW_PUT
type     ::= atype ( ARROW atype )*
atype    ::= KW_STRING
           | KW_REGEXP
           | KW_LENS
           | '(' type ')'
tree_const2
         ::= ( '{' tree_branch '}' )*
tree_branch
         ::= tree_label ( '=' DQUOTED )? tree_const2
tree_label
         ::= DQUOTED?

//Tokens

KW_MODULE ::=  "module"
KW_LET_REC ::=  "let rec"
KW_LET ::= "let"
KW_STRING ::= "string"
KW_REGEXP ::= "regexp"
KW_LENS ::= "lens"
KW_IN ::= "in"
KW_AUTOLOAD ::= "autoload"
  /* tests */
KW_TEST ::= "test"
KW_GET ::= "get"
KW_PUT ::= "put"
KW_AFTER ::= "after"