tsyn.y - plan9port - [fork] Plan 9 from user space
HTML git clone git://src.adamsgaard.dk/plan9port
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DIR README
DIR LICENSE
---
tsyn.y (3141B)
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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);}