ref: c116550e6a41572796e4db65e4f6acbcb3d9d6f8
dir: /appl/lib/w3c/uris.b/
implement URIs;
#
# RFC3986, URI Generic Syntax
#
include "sys.m";
sys: Sys;
include "string.m";
S: String;
include "uris.m";
Alpha: con "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
Digit: con "0123456789";
GenDelims: con ":/?#[]@";
SubDelims: con "!$&'()*+,;=";
Reserved: con GenDelims + SubDelims;
HexDigit: con Digit+"abcdefABCDEF";
Escape: con GenDelims+"%"; # "%" must be encoded as %25
Unreserved: con Alpha+Digit+"-._~";
F_Esc, F_Scheme: con byte(1<<iota);
ctype: array of byte;
classify(s: string, f: byte)
{
for(i := 0; i < len s; i++)
ctype[s[i]] |= f;
}
init()
{
sys = load Sys Sys->PATH;
S = load String String->PATH;
if(S == nil)
raise sys->sprint("can't load %s: %r", String->PATH);
ctype = array [256] of { * => byte 0 };
classify(Escape, F_Esc);
for(i := 0; i <= ' '; i++)
ctype[i] |= F_Esc;
for(i = 16r80; i <= 16rFF; i++)
ctype[i] |= F_Esc;
classify(Alpha+Digit+"+-.", F_Scheme);
}
# scheme://<user>:<passwd>@<host>:<port>/<path>?<query>#<fragment>
#
# ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
#
# delimiters: :/?# /?# ?# #
#
URI.parse(url: string): ref URI
{
scheme, userinfo, host, port, path, query, frag: string;
for(i := 0; i < len url; i++){
c := url[i];
if(c == ':'){
scheme = S->tolower(url[0:i]);
url = url[i+1:];
break;
}
if(c < 0 || c >= len ctype || (ctype[c] & F_Scheme) == byte 0)
break;
}
if(S->prefix("//", url)){
authority: string;
(authority, path) = S->splitstrl(url[2:], "/");
(up, hp) := splitl(authority, "@");
if(hp == "")
hp = authority;
else
userinfo = up;
if(hp != nil && hp[0] == '['){ # another rfc hack, for IPv6 addresses, which contain :
(host, hp) = S->splitstrr(hp, "]");
if(hp != nil && hp[0] == ':')
port = hp[1:];
else
host += hp; # put it back
}else
(host, port) = splitl(hp, ":");
if(path == nil)
path = "/";
}else
path = url;
(path, frag) = S->splitstrl(path, "#"); # includes # in frag
(path, query) = S->splitstrl(path, "?"); # includes ? in query
return ref URI(scheme, dec(userinfo), dec(host), port, dec(path), query, dec(frag));
}
URI.userpw(u: self ref URI): (string, string)
{
return splitl(u.userinfo, ":");
}
URI.text(u: self ref URI): string
{
s := "";
if(u.scheme != nil)
s += u.scheme + ":";
if(u.hasauthority())
s += "//" + u.authority();
return s + enc(u.path, "/@:") + u.query + enc1(u.fragment, "@:/?");
}
URI.copy(u: self ref URI): ref URI
{
return ref *u;
}
URI.pathonly(u: self ref URI): ref URI
{
v := ref *u;
v.userinfo = nil;
v.query = nil;
v.fragment = nil;
return v;
}
URI.addbase(u: self ref URI, b: ref URI): ref URI
{
# RFC3986 5.2.2, rearranged
r := ref *u;
if(r.scheme == nil && b != nil){
r.scheme = b.scheme;
if(!r.hasauthority()){
r.userinfo = b.userinfo;
r.host = b.host;
r.port = b.port;
if(r.path == nil){
r.path = b.path;
if(r.query == nil)
r.query = b.query;
}else if(r.path[0] != '/'){
# 5.2.3: merge paths
if(b.path == "" && b.hasauthority())
p1 := "/";
else
(p1, nil) = S->splitstrr(b.path, "/");
r.path = p1 + r.path;
}
}
}
r.path = removedots(r.path);
return r;
}
URI.nodots(u: self ref URI): ref URI
{
return u.addbase(nil);
}
URI.hasauthority(u: self ref URI): int
{
return u.host != nil || u.userinfo != nil || u.port != nil;
}
URI.isabsolute(u: self ref URI): int
{
return u.scheme != nil;
}
URI.authority(u: self ref URI): string
{
s := enc(u.userinfo, ":");
if(s != nil)
s += "@";
if(u.host != nil){
s += enc(u.host, "[]:"); # assumes : appears inside []; could enforce it
if(u.port != nil)
s += ":" + enc(u.port,nil);
}
return s;
}
#
# simplified version of procedure in RFC3986 5.2.4:
# it extracts a complete segment from the input first, then analyses it
#
removedots(s: string): string
{
if(s == nil)
return "";
out := "";
for(p := 0; p < len s;){
# extract the first segment and any preceding /
q := p;
if(++p < len s){
while(++p < len s && s[p] != '/')
{}
}
seg := s[q: p];
if((e := p) < len s)
e++;
case s[q: e] { # includes any following /
"../" or "./" => ;
"/./" or "/." =>
if(p >= len s)
s += "/";
"/../" or "/.." =>
if(p >= len s)
s += "/";
if(out != nil){
for(q = len out; --q > 0 && out[q] != '/';)
{} # skip
out = out[0: q];
}
"." or ".." => ; # null effect
* => # including "/"
out += seg;
}
}
return out;
}
#
# similar to splitstrl but trims the matched character from the result
#
splitl(s, c: string): (string, string)
{
(a, b) := S->splitstrl(s, c);
if(b != "")
b = b[1:];
return (a, b);
}
hex2(s: string): int
{
n := 0;
for(i := 0; i < 2; i++){
if(i >= len s)
return -1;
n <<= 4;
case c := s[i] {
'0' to '9' =>
n += c-'0';
'a' to 'f' =>
n += 10+(c-'a');
'A' to 'F' =>
n += 10+(c-'A');
* =>
return -1;
}
}
return n;
}
dec(s: string): string
{
for(i := 0;; i++){
if(i >= len s)
return s;
if(s[i] == '%' || s[i] == 0)
break;
}
t := s[0:i];
a := array[Sys->UTFmax*len s] of byte; # upper bound
o := 0;
while(i < len s){
c := s[i++];
if(c < 16r80){
case c {
'%' =>
if((v := hex2(s[i:])) > 0){
c = v;
i += 2;
}
0 =>
c = ' '; # shouldn't happen
}
a[o++] = byte c;
}else
o += sys->char2byte(c, a, o); # string contained Unicode
}
return t + string a[0:o];
}
enc1(s: string, safe: string): string
{
if(len s > 1)
return s[0:1] + enc(s[1:], safe);
return s;
}
# encoding depends on context (eg, &=/: not escaped in `query' string)
enc(s: string, safe: string): string
{
for(i := 0;; i++){
if(i >= len s)
return s; # use as-is
c := s[i];
if(c >= 16r80 || (ctype[c] & F_Esc) != byte 0 && !S->in(c, safe))
break;
}
t := s[0: i];
b := array of byte s[i:];
for(i = 0; i < len b; i++){
c := int b[i];
if((ctype[c] & F_Esc) != byte 0 && !S->in(c, safe))
t += sys->sprint("%%%.2X", c);
else
t[len t] = c;
}
return t;
}
URI.eq(u: self ref URI, v: ref URI): int
{
if(v == nil)
return 0;
return u.scheme == v.scheme && u.userinfo == v.userinfo &&
u.host == v.host && u.port == v.port && u.path == v.path && # path might need canon
u.query == v.query; # not fragment
}
URI.eqf(u: self ref URI, v: ref URI): int
{
return u.eq(v) && u.fragment == v.fragment;
}