c.y

来自「編譯器的辭法分析器工具」· Y 代码 · 共 76 行

# define TOKEN char
# define VALUE char*
# define STACKTOKENS 1
# define STACKSIZE 2048

# include "cc.h"
# include "preccx.h"
# undef UNSETNAME
# include "preamble.h"


        /* -- a shot at C-expressions -- 
           (just in order to count brackets!) */

@ atomexpr = monexpr
@          | fnexpr
@          | arrayexpr
@          | yvar
@          | cvar
@          | constant
@          | cast
@          | brktexpr

@ cast = brkttype { brkttype : VV(2)=V(2); :}* atomexpr :VV(2)=V(2);:

@ atomtype = brkttype
@          | IDENTIFIER

@ type = atomtype { WHITESPACE typeconstruct : VV(3)=V(1); : }*

@ brkttype = openparen WHITESPACE type WHITESPACE closeparen :VV(5)=V(3);:

@ star = STAR : putchar('*'); :

@ typeconstruct = star 
@               | openparen WHITESPACE closeparen     :VV(3)=V(1);:
@               | openbracket WHITESPACE closebracket :VV(3)=V(1);:

@ cvar = IDENTIFIER

@ yvar = DOLLARID

@ constant = NUMBER
@          | STRING
@          | CHARCONST


@ expr = atomexpr { WHITESPACE binop WHITESPACE expr : VV(5) = V(1); : }*

@ monexpr  = monop atomexpr : VV(2)=V(2); : 

@ fnexpr   = IDENTIFIER WHITESPACE rdbrktargs : VV(3)=V(1); : 

@ arrayexpr= IDENTIFIER WHITESPACE sqbrktargs :VV(3)=V(1);: 

@ brktexpr = openparen WHITESPACE someargs WHITESPACE closeparen : VV(5)=V(3); :

@ comment  = COMMENT

        /* overgenerous - allows arbitrary infixes so long as they have
        the right chars in them */

@ binop    = binopone { binopone : VV(2)=V(1); : }*

@ binopone = BINOPCHAR : VV(1)=putchar(T(1)); :

@ monoptwo = PLUSPLUS :VV(1)=putname("++");: 
@          | MINUSMINUS :VV(1)=putname("--");: 

@ monopone = MONOPCHAR :putchar(T(1));:

@ monop    = monoptwo
@          | monopone