ref: d916a4c3823f55227ffae35738c2497256e307b5
dir: /appl/cmd/sh/sexprs.b/
implement Shellbuiltin;
# parse/generate sexprs.
include "sys.m";
sys: Sys;
include "draw.m";
include "sh.m";
sh: Sh;
Listnode, Context: import sh;
myself: Shellbuiltin;
include "bufio.m";
bufio: Bufio;
Iobuf: import bufio;
include "sexprs.m";
sexprs: Sexprs;
Sexp: import sexprs;
# getsexprs cmd
# islist val
# ${els se}
# ${text se}
# ${textels se}
# ${mktext val}
# ${mklist [val...]}
# ${mktextlist [val...]}
Maxerrs: con 10;
initbuiltin(ctxt: ref Context, shmod: Sh): string
{
sys = load Sys Sys->PATH;
sh = shmod;
myself = load Shellbuiltin "$self";
if (myself == nil)
ctxt.fail("bad module", sys->sprint("sexpr: cannot load self: %r"));
bufio = load Bufio Bufio->PATH;
if (bufio == nil)
ctxt.fail("bad module", sys->sprint("sexpr: cannot load: %s: %r", Bufio->PATH));
sexprs = load Sexprs Sexprs->PATH;
if(sexprs == nil)
ctxt.fail("bad module", sys->sprint("sexpr: cannot load: %s: %r", Sexprs->PATH));
sexprs->init();
ctxt.addbuiltin("getsexprs", myself);
ctxt.addbuiltin("islist", myself);
ctxt.addsbuiltin("els", myself);
ctxt.addsbuiltin("text", myself);
ctxt.addsbuiltin("b64", myself);
ctxt.addsbuiltin("textels", myself);
ctxt.addsbuiltin("mktext", myself);
ctxt.addsbuiltin("mklist", myself);
ctxt.addsbuiltin("mktextlist", myself);
return nil;
}
whatis(nil: ref Sh->Context, nil: Sh, nil: string, nil: int): string
{
return nil;
}
getself(): Shellbuiltin
{
return myself;
}
runbuiltin(c: ref Sh->Context, nil: Sh,
cmd: list of ref Sh->Listnode, nil: int): string
{
case (hd cmd).word {
"getsexprs" =>
return builtin_getsexprs(c, tl cmd);
"islist" =>
return builtin_islist(c, tl cmd);
}
return nil;
}
runsbuiltin(c: ref Sh->Context, nil: Sh,
cmd: list of ref Sh->Listnode): list of ref Listnode
{
case (hd cmd).word {
"els" =>
return sbuiltin_els(c, tl cmd);
"text" =>
return sbuiltin_text(c, tl cmd);
"b64" =>
return sbuiltin_b64(c, tl cmd);
"textels" =>
return sbuiltin_textels(c, tl cmd);
"mktext" =>
return sbuiltin_mktext(c, tl cmd);
"mklist" =>
return sbuiltin_mklist(c, tl cmd);
"mktextlist" =>
return sbuiltin_mktextlist(c, tl cmd);
}
return nil;
}
builtin_getsexprs(ctxt: ref Context, argv: list of ref Listnode): string
{
n := len argv;
if (n != 1 || !iscmd(hd argv))
builtinusage(ctxt, "getsexprs {cmd}");
cmd := hd argv :: ctxt.get("*");
stdin := bufio->fopen(sys->fildes(0), Sys->OREAD);
if (stdin == nil)
ctxt.fail("bad input", sys->sprint("getsexprs: cannot open stdin: %r"));
status := "";
nerrs := 0;
ctxt.push();
for(;;){
{
for (;;) {
(se, err) := Sexp.read(stdin);
if(err != nil){
sys->fprint(sys->fildes(2), "getsexprs: error on read: %s\n", err);
if(++nerrs > Maxerrs)
raise "fail:too many errors";
continue;
}
if(se == nil)
break;
nerrs = 0;
ctxt.setlocal("sexp", ref Listnode(nil, se.text()) :: nil);
status = setstatus(ctxt, ctxt.run(cmd, 0));
}
ctxt.pop();
return status;
}exception e{
"fail:*" =>
ctxt.pop();
if (loopexcept(e) == BREAK)
return status;
ctxt.push();
}
}
}
builtin_islist(ctxt: ref Context, argv: list of ref Listnode): string
{
if(argv == nil || tl argv != nil)
builtinusage(ctxt, "islist sexp");
w := word(hd argv);
if(w != nil && w[0] =='(')
return nil;
if(parse(ctxt, hd argv).islist())
return nil;
return "not a list";
}
CONTINUE, BREAK: con iota;
loopexcept(ename: string): int
{
case ename[5:] {
"break" =>
return BREAK;
"continue" =>
return CONTINUE;
* =>
raise ename;
}
return 0;
}
iscmd(n: ref Listnode): int
{
return n.cmd != nil || (n.word != nil && n.word[0] == '{');
}
builtinusage(ctxt: ref Context, s: string)
{
ctxt.fail("usage", "usage: " + s);
}
setstatus(ctxt: ref Context, val: string): string
{
ctxt.setlocal("status", ref Listnode(nil, val) :: nil);
return val;
}
sbuiltin_els(ctxt: ref Context, val: list of ref Listnode): list of ref Listnode
{
if (val == nil || tl val != nil)
builtinusage(ctxt, "els sexp");
r, rr: list of ref Listnode;
for(els := parse(ctxt, hd val).els(); els != nil; els = tl els)
r = ref Listnode(nil, (hd els).text()) :: r;
for(; r != nil; r = tl r)
rr = hd r :: rr;
return rr;
}
sbuiltin_text(ctxt: ref Context, val: list of ref Listnode): list of ref Listnode
{
if(val == nil || tl val != nil)
builtinusage(ctxt, "text sexp");
return ref Listnode(nil, parse(ctxt, hd val).astext()) :: nil;
}
sbuiltin_b64(ctxt: ref Context, val: list of ref Listnode): list of ref Listnode
{
if(val == nil || tl val != nil)
builtinusage(ctxt, "b64 sexp");
return ref Listnode(nil, parse(ctxt, hd val).b64text()) :: nil;
}
sbuiltin_textels(ctxt: ref Context, val: list of ref Listnode): list of ref Listnode
{
if (val == nil || tl val != nil)
builtinusage(ctxt, "textels sexp");
r, rr: list of ref Listnode;
for(els := parse(ctxt, hd val).els(); els != nil; els = tl els)
r = ref Listnode(nil, (hd els).astext()) :: r;
for(; r != nil; r = tl r)
rr = hd r :: rr;
return rr;
}
sbuiltin_mktext(ctxt: ref Context, val: list of ref Listnode): list of ref Listnode
{
if (val == nil || tl val != nil)
builtinusage(ctxt, "mktext sexp");
return ref Listnode(nil, (ref Sexp.String(word(hd val), nil)).text()) :: nil;
}
sbuiltin_mklist(nil: ref Context, val: list of ref Listnode): list of ref Listnode
{
if(val == nil)
return ref Listnode(nil, "()") :: nil;
s := "(" + word(hd val);
for(val = tl val; val != nil; val = tl val)
s += " " + word(hd val);
s[len s] = ')';
return ref Listnode(nil, s) :: nil;
}
sbuiltin_mktextlist(nil: ref Context, val: list of ref Listnode): list of ref Listnode
{
if(val == nil)
return ref Listnode(nil, "()") :: nil;
s := "(" + (ref Sexp.String(word(hd val), nil)).text();
for(val = tl val; val != nil; val = tl val)
s += " " + (ref Sexp.String(word(hd val), nil)).text();
s[len s] = ')';
return ref Listnode(nil, s) :: nil;
}
parse(ctxt: ref Context, val: ref Listnode): ref Sexp
{
(se, rest, err) := Sexp.parse(word(val));
if(rest != nil){
for(i := 0; i < len rest; i++)
if(rest[i] != ' ' && rest[i] != '\t' && rest[i] != '\n')
ctxt.fail("bad sexp", sys->sprint("extra text found at end of s-expression %#q", word(val)));
}
if(err != nil)
ctxt.fail("bad sexp", err);
return se;
}
word(n: ref Listnode): string
{
if (n.word != nil)
return n.word;
if (n.cmd != nil)
n.word = sh->cmd2string(n.cmd);
return n.word;
}