kid.grammar

来自「这是一个DFA简化和生成LL(1)分析表的程序,自动生成表格及图形」· GRAMMAR 代码 · 共 68 行

program: statement_list eofile
       | <error>

statement_list: statement(s)

statement: if_statement
         | block /;?/
         | declaration
         | assignment /;?/
         | list_assignment /;?/
         | comment
         | <error>

if_statement: 'if' <commit> '(' condition ')' statement <uncommit>
              'else' <commit> else_statement
            |  'if' <commit> '(' condition ')' statement <uncommit>
            | <error?> <reject>

condition: expression rel_op <commit> rhs_expression
         | <error?> <reject>

rel_op: />=|>|<=|<>|<|=/

rhs_expression: expression

else_statement: statement

block: '{' <commit> statement_list '}'
     | <error?> <reject>

declaration: proc_decl

proc_decl: 'proc' <commit> identifier '(' identifier_list ')' block

identifier_list: identifier(s /,/)

assignment: var ':=' <commit> expression
          | <error?> <reject>

list_assignment: identifier_list ':=' <commit> expression_list
               | <error?> <reject>

var: identifier

identifier: /[A-Za-z_]\w*/

expression: <leftop: term /([-+])/ term>

term: <leftop: factor /([*\/])/ factor>
    | neg <leftop: factor /([*\/])/ factor>

neg: '-'

factor: number
      | '(' <commit> expression ')'
      | proc_call
      | var

proc_call: identifier '(' expression_list ')'

expression_list: expression(s /,/)

number: /-?\d+(?:\.\d+)?/

comment: /#.*/

eofile: /^\Z/