#define STRUCTURE \
"                                                                       \n" \
"number    : /-?[0-9]+(\\.[0-9]*)?(e[0-9]+)?/ ;                         \n" \
"factor    : '(' <lexp> ')'                                             \n" \
"          | <number>                                                   \n" \
"          | <string>                                                   \n" \
"          | <array>                                                    \n" \
"          | <hash>                                                     \n" \
"          | <lambda>                                                   \n" \
"          | <call>                                                     \n" \
"          | <item>                                                     \n" \
"          | <ident> ;                                                  \n" \
"string    : /\"[^\"]*\"/ ;                                             \n" \
"array     : '[' <lexp>? (',' <lexp>)* ']' ;                            \n" \
"pair      : <string> ':' <lexp> ;                                      \n" \
"hash      : '{' <pair>? (',' <pair>)* '}' ;                            \n" \
"ident     : /[a-zA-Z][a-zA-Z0-9_]*/ ;                                  \n" \
"                                                                       \n" \
"term      : <factor> (('*' | '/' | '%') <factor>)* ;                   \n" \
"lexp      : <term> (('+' | '-') <term>)* ;                             \n" \
"let_v     : <ident> '=' <lexp> ';' ;                                   \n" \
"item      : <factor> '[' <lexp> ']' ;                                  \n" \
"let_a     : <item> '=' <lexp> ';' ;                                    \n" \
"var       : \"var\" <ident> '=' <lexp> ';' ;                           \n" \
"vararg    : \"...\" ;                                                  \n" \
"stmts     : <stmt>* ;                                                  \n" \
"                                                                       \n" \
"lambda    : \"func\"                                                     " \
"        '(' <ident>? (<vararg> | (',' <ident>)*) ')' '{' <stmts> '}' ; \n" \
"func      : \"func\" <ident>                                             " \
"        '(' <ident>? (<vararg> | (',' <ident>)*) ')' '{' <stmts> '}' ; \n" \
"                                                                       \n" \
"call      : <ident> '(' <lexp>? (',' <lexp>)* ')' ;                    \n" \
"return    : \"return\" <lexp> ';' ;                                    \n" \
"comment   : /#[^\n]*/ ;                                                \n" \
"eof       : /$/ ;                                                      \n" \
"stmt      : (<let_v> | <let_a> | <var> | (<lexp> ';')                    " \
"            | <func> | <return> | <comment>) ;                         \n" \
"program   : <stmts> <eof> ;                                            \n"