1 %term FOR IN WHILE IF NOT TWIDDLE BANG SUBSHELL SWITCH FN
2 %term WORD REDIR DUP PIPE SUB
3 %term SIMPLE ARGLIST WORDS BRACE PAREN PCMD PIPEFD /* not used in syntax */
4 /* operator priorities -- lowest first */
5 %left IF WHILE FOR SWITCH ')' NOT
6 %left ANDAND OROR
7 %left BANG SUBSHELL
8 %left PIPE
9 %left '^'
10 %right '$' COUNT '"'
11 %left SUB
12 %{
13 #include "rc.h"
14 #include "fns.h"
15 %}
16 %union{
17 	struct tree *tree;
18 };
19 %type<tree> line paren brace body cmdsa cmdsan assign epilog redir
20 %type<tree> cmd simple first word comword keyword words
21 %type<tree> NOT FOR IN WHILE IF TWIDDLE BANG SUBSHELL SWITCH FN
22 %type<tree> WORD REDIR DUP PIPE
23 %%
24 rc:				{ return 1;}
25 |	line '\n'		{return !compile($1);}
26 line:	cmd
27 |	cmdsa line		{$$=tree2(';', $1, $2);}
28 body:	cmd
29 |	cmdsan body		{$$=tree2(';', $1, $2);}
30 cmdsa:	cmd ';'
31 |	cmd '&'			{$$=tree1('&', $1);}
32 cmdsan:	cmdsa
33 |	cmd '\n'
34 brace:	'{' body '}'		{$$=tree1(BRACE, $2);}
35 paren:	'(' body ')'		{$$=tree1(PCMD, $2);}
36 assign:	first '=' word		{$$=tree2('=', $1, $3);}
37 epilog:				{$$=0;}
38 |	redir epilog		{$$=mung2($1, $1->child[0], $2);}
39 redir:	REDIR word		{$$=mung1($1, $1->rtype==HERE?heredoc($2):$2);}
40 |	DUP
41 cmd:				{$$=0;}
42 |	brace epilog		{$$=epimung($1, $2);}
43 |	IF paren {skipnl();} cmd
44 				{$$=mung2($1, $2, $4);}
45 |	IF NOT {skipnl();} cmd	{$$=mung1($2, $4);}
46 |	FOR '(' word IN words ')' {skipnl();} cmd
47 	/*
48 	 * if ``words'' is nil, we need a tree element to distinguish between 
49 	 * for(i in ) and for(i), the former being a loop over the empty set
50 	 * and the latter being the implicit argument loop.  so if $5 is nil
51 	 * (the empty set), we represent it as "()".  don't parenthesize non-nil
52 	 * functions, to avoid growing parentheses every time we reread the
53 	 * definition.
54 	 */
55 				{$$=mung3($1, $3, $5 ? $5 : tree1(PAREN, $5), $8);}
56 |	FOR '(' word ')' {skipnl();} cmd
57 				{$$=mung3($1, $3, (struct tree *)0, $6);}
58 |	WHILE paren {skipnl();} cmd
59 				{$$=mung2($1, $2, $4);}
60 |	SWITCH word {skipnl();} brace
61 				{$$=tree2(SWITCH, $2, $4);}
62 |	simple			{$$=simplemung($1);}
63 |	TWIDDLE word words	{$$=mung2($1, $2, $3);}
64 |	cmd ANDAND cmd		{$$=tree2(ANDAND, $1, $3);}
65 |	cmd OROR cmd		{$$=tree2(OROR, $1, $3);}
66 |	cmd PIPE cmd		{$$=mung2($2, $1, $3);}
67 |	redir cmd  %prec BANG	{$$=mung2($1, $1->child[0], $2);}
68 |	assign cmd %prec BANG	{$$=mung3($1, $1->child[0], $1->child[1], $2);}
69 |	BANG cmd		{$$=mung1($1, $2);}
70 |	SUBSHELL cmd		{$$=mung1($1, $2);}
71 |	FN words brace		{$$=tree2(FN, $2, $3);}
72 |	FN words		{$$=tree1(FN, $2);}
73 simple:	first
74 |	simple word		{$$=tree2(ARGLIST, $1, $2);}
75 |	simple redir		{$$=tree2(ARGLIST, $1, $2);}
76 first:	comword	
77 |	first '^' word		{$$=tree2('^', $1, $3);}
78 word:	keyword			{lastword=1; $1->type=WORD;}
79 |	comword
80 |	word '^' word		{$$=tree2('^', $1, $3);}
81 comword: '$' word		{$$=tree1('$', $2);}
82 |	'$' word SUB words ')'	{$$=tree2(SUB, $2, $4);}
83 |	'"' word		{$$=tree1('"', $2);}
84 |	COUNT word		{$$=tree1(COUNT, $2);}
85 |	WORD
86 |	'`' brace		{$$=tree1('`', $2);}
87 |	'(' words ')'		{$$=tree1(PAREN, $2);}
88 |	REDIR brace		{$$=mung1($1, $2); $$->type=PIPEFD;}
89 keyword: FOR|IN|WHILE|IF|NOT|TWIDDLE|BANG|SUBSHELL|SWITCH|FN
90 words:				{$$=(struct tree*)0;}
91 |	words word		{$$=tree2(WORDS, $1, $2);}