1 %term FOR IN WHILE IF NOT TWIDDLE BANG SUBSHELL SWITCH FN 2 %term WORD REDIR REDIRW 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 REDIRW 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 | REDIRW 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);} 92