部分测试.xlex

词法分析器

    //注释测试
/*关键字定义*/
[Keyword_begin] //注释测试
	/*所有关键字每个一行，不能有多余字符*/
	int
[Keyword_end]

[Symbol_begin]
;
,
(
)
+
-
[Symbol_end]


[type_begin]
	/*
		新的token类型定义
		最好用大写
	*/
	NUM
	ID

[type_end]

[Regular_begin]
	digit	= [0-9]
	letter	= [a-zA-Z]
	all	= [#-~]|\s|!		// \s 为空格
	name_c	= [a-zA-Z]|_
[Regular_end]

[lex_begin]
{digit}{digit}*
NUM

{name_c}  ({name_c} | {digit})*
ID
[lex_end]

[nonterminal_begin]
type
factor
ag_exp
ag_2
addop
[nonterminal_end]

[grammer_begin]
factor = [type]
type = <int>
%(
	Set_type_int
)%

type = (num):token_id:
%(
label l1

if token_id l1

&token_id

@l1
)%

type = (id):exp_set:
%(
y setv exp_set
y sett exp_set
)%

type = [ag_2]

ag_2 = [addop]:e1:[ag_exp]:e2:
%(

)%

ag_2 = &
addop = 0+0
%(
+
)%
addop = 0-0
%(
-
)%
[grammer_end]