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-rw-r--r--appl/lib/w3c/css.b1019
1 files changed, 1019 insertions, 0 deletions
diff --git a/appl/lib/w3c/css.b b/appl/lib/w3c/css.b
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+++ b/appl/lib/w3c/css.b
@@ -0,0 +1,1019 @@
+implement CSS;
+
+#
+# CSS2 parsing module
+#
+# CSS2.1 style sheets
+#
+# Copyright © 2001, 2005 Vita Nuova Holdings Limited. All rights reserved.
+#
+
+include "sys.m";
+ sys: Sys;
+
+include "css.m";
+
+B, NUMBER, IDENT, STRING, URL, PERCENTAGE, UNIT,
+ HASH, ATKEYWORD, IMPORTANT, IMPORT, PSEUDO, CLASS, INCLUDES,
+ DASHMATCH, FUNCTION: con 16rE000+iota;
+
+toknames := array[] of{
+ B-B => "Zero",
+ NUMBER-B => "NUMBER",
+ IDENT-B => "IDENT",
+ STRING-B => "STRING",
+ URL-B => "URL",
+ PERCENTAGE-B => "PERCENTAGE",
+ UNIT-B => "UNIT",
+ HASH-B => "HASH",
+ ATKEYWORD-B => "ATKEYWORD",
+ IMPORTANT-B => "IMPORTANT",
+ CLASS-B => "CLASS",
+ INCLUDES-B => "INCLUDES",
+ DASHMATCH-B => "DASHMATCH",
+ PSEUDO-B => "PSEUDO",
+ FUNCTION-B => "FUNCTION",
+};
+
+printdiag := 0;
+
+init(d: int)
+{
+ sys = load Sys Sys->PATH;
+ printdiag = d;
+}
+
+parse(s: string): (ref Stylesheet, string)
+{
+ return stylesheet(ref Cparse(-1, 0, nil, nil, Clex.new(s,1)));
+}
+
+parsedecl(s: string): (list of ref Decl, string)
+{
+ return (declarations(ref Cparse(-1, 0, nil, nil, Clex.new(s,0))), nil);
+}
+
+ptok(c: int): string
+{
+ if(c < 0)
+ return "eof";
+ if(c == 0)
+ return "zero?";
+ if(c >= B)
+ return sys->sprint("%s", toknames[c-B]);
+ return sys->sprint("%c", c);
+}
+
+Cparse: adt {
+ lookahead: int;
+ eof: int;
+ value: string;
+ suffix: string;
+ cs: ref Clex;
+
+ get: fn(nil: self ref Cparse): int;
+ look: fn(nil: self ref Cparse): int;
+ unget: fn(nil: self ref Cparse, tok: int);
+ skipto: fn(nil: self ref Cparse, followset: string): int;
+ synerr: fn(nil: self ref Cparse, s: string);
+};
+
+Cparse.get(p: self ref Cparse): int
+{
+ if((c := p.lookahead) >= 0){
+ p.lookahead = -1;
+ return c;
+ }
+ if(p.eof)
+ return -1;
+ (c, p.value, p.suffix) = csslex(p.cs);
+ if(c < 0)
+ p.eof = 1;
+ if(printdiag > 1)
+ sys->print("lex: %s v=%s s=%s\n", ptok(c), p.value, p.suffix);
+ return c;
+}
+
+Cparse.look(p: self ref Cparse): int
+{
+ c := p.get();
+ p.unget(c);
+ return c;
+}
+
+Cparse.unget(p: self ref Cparse, c: int)
+{
+ if(p.lookahead >= 0)
+ raise "css: internal error: Cparse.unget";
+ p.lookahead = c; # note that p.value and p.suffix are assumed to be those of c
+}
+
+Cparse.skipto(p: self ref Cparse, followset: string): int
+{
+ while((c := p.get()) >= 0)
+ for(i := 0; i < len followset; i++)
+ if(followset[i] == c){
+ p.unget(c);
+ return c;
+ }
+ return -1;
+}
+
+Cparse.synerr(p: self ref Cparse, s: string)
+{
+ p.cs.synerr(s);
+}
+
+#
+# stylesheet:
+# ["@charset" STRING ';']?
+# [CDO|CDC]* [import [CDO|CDC]*]*
+# [[ruleset | media | page ] [CDO|CDC]*]*
+# import:
+# "@import" [STRING|URL] [ medium [',' medium]*]? ';'
+# media:
+# "@media" medium [',' medium]* '{' ruleset* '}'
+# medium:
+# IDENT
+# page:
+# "@page" pseudo_page? '{' declaration [';' declaration]* '}'
+# pseudo_page:
+# ':' IDENT
+#
+
+stylesheet(p: ref Cparse): (ref Stylesheet, string)
+{
+ charset: string;
+ if(atkeywd(p, "@charset")){
+ if(itisa(p, STRING)){
+ charset = p.value;
+ itisa(p, ';');
+ }else
+ p.synerr("bad @charset declaration");
+ }
+ imports: list of ref Import;
+ while(atkeywd(p, "@import")){
+ c := p.get();
+ if(c == STRING || c == URL){
+ name := p.value;
+ media: list of string;
+ c = p.get();
+ if(c == IDENT){ # optional medium [, ...]
+ p.unget(c);
+ media = medialist(p);
+ }
+ imports = ref Import(name, media) :: imports;
+ }else
+ p.synerr("bad @import");
+ if(c != ';'){
+ p.synerr("missing ; in @import");
+ p.unget(c);
+ if(p.skipto(";}") < 0)
+ break;
+ }
+ }
+ imports = rev(imports);
+
+ stmts: list of ref Statement;
+ do{
+ while((c := p.get()) == ATKEYWORD)
+ case p.value {
+ "@media" => # medium[,medium]* { ruleset*}
+ media := medialist(p);
+ if(!itisa(p, '{')){
+ p.synerr("bad @media");
+ skipatrule("@media", p);
+ continue;
+ }
+ rules: list of ref Statement.Ruleset;
+ do{
+ rule := checkrule(p);
+ if(rule != nil)
+ rules = rule :: rules;
+ }while(!itisa(p, '}') && !p.eof);
+ stmts = ref Statement.Media(media, rev(rules)) :: stmts;
+ "@page" => # [:ident]? { declaration [; declaration]* }
+ pseudo: string;
+ if(itisa(p, PSEUDO))
+ pseudo = p.value;
+ if(!itisa(p, '{')){
+ p.synerr("bad @page");
+ skipatrule("@page", p);
+ continue;
+ }
+ decls := declarations(p);
+ if(!itisa(p, '}')){
+ p.synerr("unclosed @page declaration block");
+ skipatrule("@page", p);
+ continue;
+ }
+ stmts = ref Statement.Page(pseudo, decls) :: stmts;
+ * =>
+ skipatrule(p.value, p); # skip unknown or misplaced at-rule
+ }
+ p.unget(c);
+ rule := checkrule(p);
+ if(rule != nil)
+ stmts = rule :: stmts;
+ }while(!p.eof);
+ rl := stmts;
+ stmts = nil;
+ for(; rl != nil; rl = tl rl)
+ stmts = hd rl :: stmts;
+ return (ref Stylesheet(charset, imports, stmts), nil);
+}
+
+checkrule(p: ref Cparse): ref Statement.Ruleset
+{
+ (rule, err) := ruleset(p);
+ if(rule == nil){
+ if(err != nil){
+ p.synerr(sys->sprint("bad ruleset: %s", err));
+ p.get(); # make some progress
+ }
+ }
+ return rule;
+}
+
+medialist(p: ref Cparse): list of string
+{
+ media: list of string;
+ do{
+ c := p.get();
+ if(c != IDENT){
+ p.unget(c);
+ p.synerr("missing medium identifier");
+ break;
+ }
+ media = p.value :: media;
+ }while(itisa(p, ','));
+ return rev(media);
+}
+
+itisa(p: ref Cparse, expect: int): int
+{
+ if((c := p.get()) == expect)
+ return 1;
+ p.unget(c);
+ return 0;
+}
+
+atkeywd(p: ref Cparse, expect: string): int
+{
+ if((c := p.get()) == ATKEYWORD && p.value == expect)
+ return 1;
+ p.unget(c);
+ return 0;
+}
+
+skipatrule(name: string, p: ref Cparse)
+{
+ if(printdiag)
+ sys->print("skip unimplemented or misplaced %s\n", name);
+ if((c := p.get()) == '{'){ # block
+ for(nesting := '}' :: nil; nesting != nil && c >= 0; nesting = tl nesting){
+ while((c = p.cs.getc()) >= 0 && c != hd nesting)
+ case c {
+ '{' =>
+ nesting = '}' :: nesting;
+ '(' =>
+ nesting = ')' :: nesting;
+ '[' =>
+ nesting = ']' :: nesting;
+ '"' or '\'' =>
+ quotedstring(p.cs, c);
+ }
+ }
+ }else{
+ while(c >= 0 && c != ';')
+ c = p.get();
+ }
+}
+
+# ruleset:
+# selector [',' S* selector]* '{' S* declaration [';' S* declaration]* '}' S*
+
+ruleset(p: ref Cparse): (ref Statement.Ruleset, string)
+{
+ selectors: list of list of (int, list of ref Select);
+ c := -1;
+ do{
+ s := selector(p);
+ if(s == nil){
+ if(p.eof)
+ return (nil, nil);
+ p.synerr("expected selector");
+ if(p.skipto(",{}") < 0)
+ return (nil, nil);
+ c = p.look();
+ }else
+ selectors = s :: selectors;
+ }while((c = p.get()) == ',');
+ if(c != '{')
+ return (nil, "expected declaration block");
+ sl := selectors;
+ selectors = nil;
+ for(; sl != nil; sl = tl sl)
+ selectors = hd sl :: selectors;
+ decls := declarations(p);
+ if(!itisa(p, '}')){
+ p.synerr("unclosed declaration block");
+ }
+ return (ref Statement.Ruleset(selectors, decls), nil);
+}
+
+declarations(p: ref Cparse): list of ref Decl
+{
+ decls: list of ref Decl;
+ c: int;
+ do{
+ (d, e) := declaration(p);
+ if(d != nil)
+ decls = d :: decls;
+ else if(e != nil){
+ p.synerr("ruleset declaration: "+e);
+ if((c = p.skipto(";}")) < 0)
+ break;
+ }
+ }while((c = p.get()) == ';');
+ p.unget(c);
+ l := decls;
+ for(decls = nil; l != nil; l = tl l)
+ decls = hd l :: decls;
+ return decls;
+}
+
+# selector:
+# simple_selector [combinator simple_selector]*
+# combinator:
+# '+' S* | '>' S* | /* empty */
+#
+
+selector(p: ref Cparse): list of (int, list of ref Select)
+{
+ sel: list of (int, list of ref Select);
+ op := ' ';
+ while((s := selector1(p)) != nil){
+ sel = (op, s) :: sel;
+ if((c := p.look()) == '+' || c == '>')
+ op = p.get();
+ else
+ op = ' ';
+ }
+ l: list of (int, list of ref Select);
+ for(; sel != nil; sel = tl sel)
+ l = hd sel :: l;
+ return l;
+}
+
+#
+# simple_selector:
+# element_name? [HASH | class | attrib | pseudo]* S*
+# element_name:
+# IDENT | '*'
+# class:
+# '.' IDENT
+# attrib:
+# '[' S* IDENT S* [ [ '=' | INCLUDES | DASHMATCH ] S* [IDENT | STRING] S* ]? ']'
+# pseudo
+# ':' [ IDENT | FUNCTION S* IDENT? S* ')' ]
+
+selector1(p: ref Cparse): list of ref Select
+{
+ sel: list of ref Select;
+ c := p.get();
+ if(c == IDENT)
+ sel = ref Select.Element(p.value) :: sel;
+ else if(c== '*')
+ sel = ref Select.Any("*") :: sel;
+ else
+ p.unget(c);
+Sel:
+ for(;;){
+ c = p.get();
+ case c {
+ HASH =>
+ sel = ref Select.ID(p.value) :: sel;
+ CLASS =>
+ sel = ref Select.Class(p.value) :: sel;
+ '[' =>
+ if(!itisa(p, IDENT))
+ break;
+ name := p.value;
+ case c = p.get() {
+ '=' =>
+ sel = ref Select.Attrib(name, "=", optaval(p)) :: sel;
+ INCLUDES =>
+ sel = ref Select.Attrib(name, "~=", optaval(p)) :: sel;
+ DASHMATCH =>
+ sel = ref Select.Attrib(name, "|=", optaval(p)) :: sel;
+ * =>
+ sel = ref Select.Attrib(name, nil, nil) :: sel;
+ p.unget(c);
+ }
+ if((c = p.get()) != ']'){
+ p.synerr("bad attribute syntax");
+ p.unget(c);
+ break Sel;
+ }
+ PSEUDO =>
+ case c = p.get() {
+ IDENT =>
+ sel = ref Select.Pseudo(p.value) :: sel;
+ FUNCTION =>
+ name := p.value;
+ case c = p.get() {
+ IDENT =>
+ sel = ref Select.Pseudofn(name, lowercase(p.value)) :: sel;
+ ')' =>
+ p.unget(c);
+ sel = ref Select.Pseudofn(name, nil) :: sel;
+ * =>
+ p.synerr("bad pseudo-function syntax");
+ p.unget(c);
+ break Sel;
+ }
+ if((c = p.get()) != ')'){
+ p.synerr("missing ')' for pseudo-function");
+ p.unget(c);
+ break Sel;
+ }
+ * =>
+ p.synerr(sys->sprint("unexpected :pseudo: %s:%s", ptok(c), p.value));
+ p.unget(c);
+ break Sel;
+ }
+ * =>
+ p.unget(c);
+ break Sel;
+ }
+ # qualifiers must be adjacent to the first item, and each other
+ c = p.cs.getc();
+ p.cs.ungetc(c);
+ if(isspace(c))
+ break;
+ }
+ sl := sel;
+ for(sel = nil; sl != nil; sl = tl sl)
+ sel = hd sl :: sel;
+ return sel;
+}
+
+optaval(p: ref Cparse): ref Value
+{
+ case c := p.get() {
+ IDENT =>
+ return ref Value.Ident(' ', p.value);
+ STRING =>
+ return ref Value.String(' ', p.value);
+ * =>
+ p.unget(c);
+ return nil;
+ }
+}
+
+# declaration:
+# property ':' S* expr prio?
+# | /* empty */
+# property:
+# IDENT
+# prio:
+# IMPORTANT S* /* ! important */
+
+declaration(p: ref Cparse): (ref Decl, string)
+{
+ c := p.get();
+ if(c != IDENT){
+ p.unget(c);
+ return (nil, nil);
+ }
+ prop := lowercase(p.value);
+ c = p.get();
+ if(c != ':'){
+ p.unget(c);
+ return (nil, "missing :");
+ }
+ values := expr(p);
+ if(values == nil)
+ return (nil, "missing expression(s)");
+ prio := 0;
+ if(p.look() == IMPORTANT){
+ p.get();
+ prio = 1;
+ }
+ return (ref Decl(prop, values, prio), nil);
+}
+
+# expr:
+# term [operator term]*
+# operator:
+# '/' | ',' | /* empty */
+
+expr(p: ref Cparse): list of ref Value
+{
+ values: list of ref Value;
+ sep := ' ';
+ while((t := term(p, sep)) != nil){
+ values = t :: values;
+ if((c := p.look()) == '/' || c == ',')
+ sep = p.get(); # need something fancier here?
+ else
+ sep = ' ';
+ }
+ vl := values;
+ for(values = nil; vl != nil; vl = tl vl)
+ values = hd vl :: values;
+ return values;
+}
+
+#
+# term:
+# unary_operator? [NUMBER | PERCENTAGE | LENGTH | EMS | EXS | ANGLE | TIME | FREQ | function]
+# | STRING | IDENT | URI | RGB | UNICODERANGE | hexcolour
+# function:
+# FUNCTION expr ')'
+# unary_operator:
+# '-' | '+'
+# hexcolour:
+# HASH S*
+#
+# LENGTH, EMS, ... FREQ have been combined into UNIT here
+#
+# TO DO: UNICODERANGE
+
+term(p: ref Cparse, sep: int): ref Value
+{
+ prefix: string;
+ case p.look(){
+ '+' or '-' =>
+ prefix[0] = p.get();
+ }
+ c := p.get();
+ case c {
+ NUMBER =>
+ return ref Value.Number(sep, prefix+p.value);
+ PERCENTAGE =>
+ return ref Value.Percentage(sep, prefix+p.value);
+ UNIT =>
+ return ref Value.Unit(sep, prefix+p.value, p.suffix);
+ }
+ if(prefix != nil)
+ p.synerr("+/- before non-numeric");
+ case c {
+ STRING =>
+ return ref Value.String(sep, p.value);
+ IDENT =>
+ return ref Value.Ident(sep, lowercase(p.value));
+ URL =>
+ return ref Value.Url(sep, p.value);
+ HASH =>
+ # could check value: 3 or 6 hex digits
+ (r, g, b) := torgb(p.value);
+ if(r < 0)
+ return nil;
+ return ref Value.Hexcolour(sep, p.value, (r,g,b));
+ FUNCTION =>
+ name := p.value;
+ args := expr(p);
+ c = p.get();
+ if(c != ')'){
+ p.synerr(sys->sprint("missing ')' for function %s", name));
+ return nil;
+ }
+ if(name == "rgb"){
+ if(len args != 3){
+ p.synerr("wrong number of arguments to rgb()");
+ return nil;
+ }
+ r := colourof(hd args);
+ g := colourof(hd tl args);
+ b := colourof(hd tl tl args);
+ if(r < 0 || g < 0 || b < 0){
+ p.synerr("invalid rgb() parameters");
+ return nil;
+ }
+ return ref Value.RGB(sep, args, (r,g,b));
+ }
+ return ref Value.Function(sep, name, args);
+ * =>
+ p.unget(c);
+ return nil;
+ }
+}
+
+torgb(s: string): (int, int, int)
+{
+ case len s {
+ 3 =>
+ r := hex(s[0]);
+ g := hex(s[1]);
+ b := hex(s[2]);
+ if(r >= 0 && g >= 0 && b >= 0)
+ return ((r<<4)|r, (g<<4)|g, (b<<4)|b);
+ 6 =>
+ v := 0;
+ for(i := 0; i < 6; i++){
+ n := hex(s[i]);
+ if(n < 0)
+ return (-1, 0, 0);
+ v = (v<<4) | n;
+ }
+ return (v>>16, (v>>8)&16rFF, v&16rFF);
+ }
+ return (-1, 0, 0);
+}
+
+colourof(v: ref Value): int
+{
+ pick r := v {
+ Number =>
+ return clip(int r.value, 0, 255);
+ Percentage =>
+ # just the integer part
+ return clip((int r.value*255 + 50)/100, 0, 255);
+ * =>
+ return -1;
+ }
+}
+
+clip(v: int, l: int, u: int): int
+{
+ if(v < l)
+ return l;
+ if(v > u)
+ return u;
+ return v;
+}
+
+rev[T](l: list of T): list of T
+{
+ t: list of T;
+ for(; l != nil; l = tl l)
+ t = hd l :: t;
+ return t;
+}
+
+Clex: adt {
+ context: list of int; # characters
+ input: string;
+ lim: int;
+ n: int;
+ lineno: int;
+
+ new: fn(s: string, lno: int): ref Clex;
+ getc: fn(cs: self ref Clex): int;
+ ungetc: fn(cs: self ref Clex, c: int);
+ synerr: fn(nil: self ref Clex, s: string);
+};
+
+Clex.new(s: string, lno: int): ref Clex
+{
+ return ref Clex(nil, s, len s, 0, lno);
+}
+
+Clex.getc(cs: self ref Clex): int
+{
+ if(cs.context != nil){
+ c := hd cs.context;
+ cs.context = tl cs.context;
+ return c;
+ }
+ if(cs.n >= cs.lim)
+ return -1;
+ c := cs.input[cs.n++];
+ if(c == '\n')
+ cs.lineno++;
+ return c;
+}
+
+Clex.ungetc(cs: self ref Clex, c: int)
+{
+ cs.context = c :: cs.context;
+}
+
+Clex.synerr(cs: self ref Clex, s: string)
+{
+ if(printdiag)
+ sys->fprint(sys->fildes(2), "%d: err: %s\n", cs.lineno, s);
+}
+
+csslex(cs: ref Clex): (int, string, string)
+{
+ for(;;){
+ c := skipws(cs);
+ if(c < 0)
+ return (-1, nil, nil);
+ case c {
+ '<' =>
+ if(seq(cs, "!--"))
+ break; # <!-- ignore HTML comment start (CDO)
+ return (c, nil, nil);
+ '-' =>
+ if(seq(cs, "->"))
+ break; # --> ignore HTML comment end (CDC)
+ return (c, nil, nil);
+ ':' =>
+ c = cs.getc();
+ cs.ungetc(c);
+ if(isnamec(c, 0))
+ return (PSEUDO, nil, nil);
+ return (':', nil, nil);
+ '#' =>
+ c = cs.getc();
+ if(isnamec(c, 1))
+ return (HASH, name(cs, c), nil);
+ cs.ungetc(c);
+ return ('#', nil, nil);
+ '/' =>
+ if(subseq(cs, '*', 1, 0)){
+ comment(cs);
+ break;
+ }
+ return (c, nil, nil);
+ '\'' or '"' =>
+ return (STRING, quotedstring(cs, c), nil);
+ '0' to '9' or '.' =>
+ if(c == '.'){
+ d := cs.getc();
+ cs.ungetc(d);
+ if(!isdigit(d)){
+ if(isnamec(d, 1))
+ return (CLASS, name(cs, cs.getc()), nil);
+ return ('.', nil, nil);
+ }
+ # apply CSS2 treatment: .55 is a number not a class
+ }
+ val := number(cs, c);
+ c = cs.getc();
+ if(c == '%')
+ return (PERCENTAGE, val, "%");
+ if(isnamec(c, 0)) # use CSS2 interpetation
+ return (UNIT, val, lowercase(name(cs, c)));
+ cs.ungetc(c);
+ return (NUMBER, val, nil);
+ '\\' =>
+ d := cs.getc();
+ if(d >= ' ' && d <= '~' || islatin1(d)){ # probably should handle it in name
+ wd := name(cs, d);
+ return (IDENT, "\\"+wd, nil);
+ }
+ cs.ungetc(d);
+ return ('\\', nil, nil);
+ '@' =>
+ c = cs.getc();
+ if(isnamec(c, 0)) # @something
+ return (ATKEYWORD, "@"+lowercase(name(cs,c)), nil);
+ cs.ungetc(c);
+ return ('@', nil, nil);
+ '!' =>
+ c = skipws(cs);
+ if(isnamec(c, 0)){ # !something
+ wd := name(cs, c);
+ if(lowercase(wd) == "important")
+ return (IMPORTANT, nil, nil);
+ pushback(cs, wd);
+ }else
+ cs.ungetc(c);
+ return ('!', nil, nil);
+ '~' =>
+ if(subseq(cs, '=', 1, 0))
+ return (INCLUDES, "~=", nil);
+ return ('~', nil, nil);
+ '|' =>
+ if(subseq(cs, '=', 1, 0))
+ return (DASHMATCH, "|=", nil);
+ return ('|', nil, nil);
+ * =>
+ if(isnamec(c, 0)){
+ wd := name(cs, c);
+ d := cs.getc();
+ if(d != '('){
+ cs.ungetc(d);
+ return (IDENT, wd, nil);
+ }
+ val := lowercase(wd);
+ if(val == "url")
+ return (URL, url(cs), nil); # bizarre special case
+ return (FUNCTION, val, nil);
+ }
+ return (c, nil, nil);
+ }
+
+ }
+}
+
+skipws(cs: ref Clex): int
+{
+ for(;;){
+ while((c := cs.getc()) == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\f')
+ ;
+ if(c != '/')
+ return c;
+ c = cs.getc();
+ if(c != '*'){
+ cs.ungetc(c);
+ return '/';
+ }
+ comment(cs);
+ }
+}
+
+seq(cs: ref Clex, s: string): int
+{
+ for(i := 0; i < len s; i++)
+ if((c := cs.getc()) != s[i])
+ break;
+ if(i == len s)
+ return 1;
+ cs.ungetc(c);
+ while(i > 0)
+ cs.ungetc(s[--i]);
+ if(c < 0)
+ return -1;
+ return 0;
+}
+
+subseq(cs: ref Clex, a: int, t: int, e: int): int
+{
+ if((c := cs.getc()) != a){
+ cs.ungetc(c);
+ return e;
+ }
+ return t;
+}
+
+pushback(cs: ref Clex, wd: string)
+{
+ for(i := len wd; --i >= 0;)
+ cs.ungetc(wd[i]);
+}
+
+comment(cs: ref Clex)
+{
+ while((c := cs.getc()) != '*' || (c = cs.getc()) != '/')
+ if(c < 0) {
+ # end of file in comment
+ break;
+ }
+}
+
+number(cs: ref Clex, c: int): string
+{
+ s: string;
+ for(; isdigit(c); c = cs.getc())
+ s[len s] = c;
+ if(c != '.'){
+ cs.ungetc(c);
+ return s;
+ }
+ if(!isdigit(c = cs.getc())){
+ cs.ungetc(c);
+ cs.ungetc('.');
+ return s;
+ }
+ s[len s] = '.';
+ do{
+ s[len s] = c;
+ }while(isdigit(c = cs.getc()));
+ cs.ungetc(c);
+ return s;
+}
+
+name(cs: ref Clex, c: int): string
+{
+ s: string;
+ for(; isnamec(c, 1); c = cs.getc()){
+ s[len s] = c;
+ if(c == '\\'){
+ c = cs.getc();
+ if(isescapable(c))
+ s[len s] = c;
+ }
+ }
+ cs.ungetc(c);
+ return s;
+}
+
+isescapable(c: int): int
+{
+ return c >= ' ' && c <= '~' || isnamec(c, 1);
+}
+
+islatin1(c: int): int
+{
+ return c >= 16rA1 && c <= 16rFF; # printable latin-1
+}
+
+isnamec(c: int, notfirst: int): int
+{
+ return c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z' || c == '\\' ||
+ notfirst && (c >= '0' && c <= '9' || c == '-') ||
+ c >= 16rA1 && c <= 16rFF; # printable latin-1
+}
+
+isxdigit(c: int): int
+{
+ return c>='0' && c<='9' || c>='a'&&c<='f' || c>='A'&&c<='F';
+}
+
+isdigit(c: int): int
+{
+ return c >= '0' && c <= '9';
+}
+
+isspace(c: int): int
+{
+ return c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\f';
+}
+
+hex(c: int): int
+{
+ if(c >= '0' && c <= '9')
+ return c-'0';
+ if(c >= 'A' && c <= 'F')
+ return c-'A' + 10;
+ if(c >= 'a' && c <= 'f')
+ return c-'a' + 10;
+ return -1;
+}
+
+quotedstring(cs: ref Clex, delim: int): string
+{
+ s: string;
+ while((c := cs.getc()) != delim){
+ if(c < 0){
+ cs.synerr("end-of-file in string");
+ return s;
+ }
+ if(c == '\\'){
+ c = cs.getc();
+ if(c < 0){
+ cs.synerr("end-of-file in string");
+ return s;
+ }
+ if(isxdigit(c)){
+ # unicode escape
+ n := 0;
+ for(i := 0;;){
+ n = (n<<4) | hex(c);
+ c = cs.getc();
+ if(!isxdigit(c) || ++i >= 6){
+ if(!isspace(c))
+ cs.ungetc(c); # CSS2 ignores the first white space following
+ break;
+ }
+ }
+ s[len s] = n;
+ }else if(c == '\n'){
+ ; # escaped newline
+ }else if(isescapable(c))
+ s[len s] = c;
+ }else if(c)
+ s[len s] = c;
+ }
+ return s;
+}
+
+url(cs: ref Clex): string
+{
+ s: string;
+ c := skipws(cs);
+ if(c != '"' && c != '\''){ # not a quoted string
+ while(c != ' ' && c != '\n' && c != '\'' && c != '"' && c != ')'){
+ s[len s] = c;
+ c = cs.getc();
+ if(c == '\\'){
+ c = cs.getc();
+ if(c < 0){
+ cs.synerr("end of file in url parameter");
+ break;
+ }
+ if(c == ' ' || c == '\'' || c == '"' || c == ')')
+ s[len s] = c;
+ else{
+ cs.synerr("invalid escape sequence in url");
+ s[len s] = '\\';
+ s[len s] = c;
+ }
+ c = cs.getc();
+ }
+ }
+ cs.ungetc(c);
+# if(s == nil)
+# p.synerr("empty parameter to url");
+ }else
+ s = quotedstring(cs, c);
+ if((c = skipws(cs)) != ')'){
+ cs.synerr("unclosed parameter to url");
+ cs.ungetc(c);
+ }
+ return s;
+}
+
+lowercase(s: string): string
+{
+ for(i := 0; i < len s; i++)
+ if((c := s[i]) >= 'A' && c <= 'Z')
+ s[i] = c-'A' + 'a';
+ return s;
+}
generated by cgit v1.2.3 (git 2.46.0) at 2025-12-10 10:58:12 +0000