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|
lex start
{
ignore /[\t\n ]+/
literal '^', '|', '-', ',', ':', '!', '?', '.'
literal '(', ')', '{', '}', '*', '&', '+'
literal '--', ':>', ':>>', '<:', '->', '**'
token word /[a-zA-Z_][a-zA-Z0-9_]*/
token uint /[0-9]+/
}
def start
[expression]
{
print_xml( lhs )
}
def expression [term expression_op*]
def expression_op
['|' term]
| ['&' term]
| ['-' term]
| ['--' term]
def term [factor_rep term_op_list_short]
# This list is done manually to get shortest match.
def term_op_list_short
[]
| [term_op term_op_list_short]
def term_op
[factor_rep]
| ['.' factor_rep]
| [':>' factor_rep]
| [':>>' factor_rep]
| ['<:' factor_rep]
def factor_rep
[factor_neg factor_rep_op*]
def factor_rep_op
['*']
| ['**']
| ['?']
| ['+']
| ['{' factor_rep_num '}']
| ['{' ',' factor_rep_num '}']
| ['{' factor_rep_num ',' '}']
| ['{' factor_rep_num ',' factor_rep_num '}']
def factor_rep_num [uint]
def factor_neg
['!' factor_neg]
| ['^' factor_neg]
| [factor]
def factor
[alphabet_num]
| [word]
| ['(' expression ')']
def alphabet_num
[uint]
| ['-' uint]
parse start[ stdin ]
print( '\n' )
|
