1 files changed, 453 insertions, 0 deletions

diff --git a/src/lang/parse.cc b/src/lang/parse.cc
new file mode 100644
index 0000000..7e24a11
--- /dev/null
+++ b/src/lang/parse.cc
@@ -0,0 +1,453 @@
+/*************************************************************************
+ *
+ * HTCd - Copyright (C) 1998-2006 Henrik Rydberg
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <lang/env.h>
+
+static const charset escaped("%$[]{};");
+static const charset prename("\"'`^~*,_=!\\");
+static const charset spec("+-*/%<=>^_!~&|,?:;");
+static const charset spec_latex("+-*/<=>^_;");
+static const charset delim("\"{}()\\");
+static const charset delim_latex("{}()[]\\");
+static const charset specws=spec|delim|cset_ws;
+static const charset specws_latex=spec_latex|delim_latex|cset_ws;
+static const charset tokname=cset_alphareal;
+static const charset pretok=tokname|prename;
+
+const mstring begin_tag="begin",end_left="\\end{",end_right="}";
+
+int is_tokname(const sref& s) {
+  return s.back()!='.'&&pretok.test(s.front())&&s.right(1).find_not_of(tokname)<0;
+}
+
+int is_arglist(const sref& s)
+{
+  const char* p=s.begin(); int opt=0;
+  if(*p=='?') { ++p; opt=1; }
+  while(*p=='x') ++p;
+  while(*p=='r') ++p;
+  if(!opt&&*p=='?') ++p;
+  if(*p=='*') ++p;
+  return !*p;
+}
+
+///////////////////////////////////////////////////////////
+
+static sref getlocal(const sref& in) {
+  int w=0,i=0; for(;i<in.size();i++) {
+    if(in[i]=='[') w++;
+    else if(in[i]==']') w--;
+    else if(!w&&specws.test(in[i])) break;
+  }
+  return in.left(i);
+}
+
+static sref getname(const sref& in) {
+  int i=0;
+  if(pretok.test(*in)) {
+    int w=0;
+    for(i=1;i<in.size();i++) {
+      if(in[i]=='[') w++;
+      else if(in[i]==']') w--;
+      else if(!w&&!tokname.test(in[i])) break;
+    }
+  }
+  if(i>0&&in[i-1]=='.') return in.left(i-1);
+  else return in.left(i);
+}
+
+static int skip_quotes(const sref& in) throw(merror_t) {
+  int s=in.skip(cset_quotes);
+  if(s<0) THROW("parse: unmatched '\"'");
+  return s;
+}
+
+static int skip_braces(const sref& in) throw(merror_t) {
+  int s=in.skip(cset_braces);
+  if(s<0) THROW("parse: unmatched '{'");
+  return s;
+}
+
+static int skip_para(const sref& in) throw(merror_t) {
+  int s=in.skip(cset_para);
+  if(s<0) THROW("parse: unmatched '('");
+  return s;
+} 
+
+static int skip_indices(const sref& in) throw(merror_t) {
+  int s=in.skip(cset_indices);
+  if(s<0) THROW("parse: unmatched '['");
+  return s;
+} 
+
+static int skip_dollars(const sref& in) throw(merror_t) {
+  int s=in.skip(cset_dollars);
+  //if(s<0) THROW("parse: unmatched '$'");
+  return s;
+} 
+
+///////////////////////////////////////////////////////////
+
+static int count_args(const sref& in) throw(merror_t)
+{
+  sref e=in.right_first_not_of(cset_ws);
+  int s,n=0; while((s=skip_braces(e))>0||(s=skip_para(e))>0) {
+    e=e.adv(s).right_first_not_of(cset_ws); n++;
+  }
+  return n;
+}
+
+static int past_args(const sref& in) throw(merror_t)
+{
+  sref p=in,e=in.right_first_not_of(cset_ws);
+  int s; while((s=skip_braces(e))>0||(s=skip_para(e))>0) {
+    e=(p=e.adv(s)).right_first_not_of(cset_ws);
+  }
+  return p-in;
+}
+
+static int parse_args(Env& env,runnable_t* ftok,const sref& in,int inbegend) throw(merror_t)
+{
+  env.clear_args();
+  sref option,p=in,e=in.right_first_not_of(cset_ws);
+  int s,narg=0,carg=count_args(e);
+  while((s=e.skip(cset_braces))>0||(s==0&&(s=e.skip(cset_para))>0)) {
+    if(ftok->arg[narg]=='?'&&carg<ftok->arg.size()) narg++;
+    switch(ftok->arg[narg]){
+    case 'x': env.xpush(e.left(s)); break;
+    case 'r': case '*': env.rpush(e.left(s)); break;
+    case '?': option=e.left(s); break;
+    case 0: THROW("htc: too many args in "<<ftok->name);
+    default: THROW("htc: bad argument descriptor in "<<ftok->name);
+    }
+    e=(p=e.adv(s)).right_first_not_of(cset_ws);
+    if(ftok->arg[narg]!='*') narg++;
+  }
+  if(s<0) THROW("htc: unmatched parenthesis in function "<<ftok->name);
+  if(inbegend) {
+    mstring tag=end_left+ftok->name+end_right;
+    s=p.find(tag); if(s<0) THROW("htc: unmatched begin/end in function "<<ftok->name);
+    if(ftok->arg[narg]=='?'&&carg<ftok->arg.size()) narg++;
+    switch(ftok->arg[narg]){
+    case 'x': env.xpush(p.left(s)); break;
+    case 'r': case '*': env.rpush(p.left(s)); break;
+    case '?': option=p.left(s); break;
+    case 0: THROW("htc: too many args in begin/end "<<ftok->name);
+    default: THROW("htc: bad argument descriptor in "<<ftok->name);
+    }
+    p=p.adv(s+tag.size());
+  }
+  if(ftok->arg.find('?')>=0&&env.args<ftok->arg.size()) env.rpush(option);
+  return p-in;
+}
+
+int Env::check_arg(const runnable_t& ftok) const
+{
+  static const charset tag("xr?");
+  const char* p=ftok.arg.begin(); int x=0,r=0,o=0;
+  while(tag.test(*p)) {
+    switch(*p++) {
+    case 'x': x++; break;
+    case 'r': r++; break;
+    case '?': r++; o++; break;
+    }
+  }
+  if(*p=='*') { o++; ++p; }
+  if(*p||x!=xsize()||o>1||o==1&&rsize()<r||o==0&&r!=rsize()) return 0;
+  return 1;
+}
+
+///////////////////////////////////////////////////////////
+
+void Env::expr(mstream& out,const sref& in) throw(merror_t)
+{
+  expr_t x(in);
+  x.expand(*this);
+  x.eval(out,*this,OP_ALL);
+}
+
+void Env::xpush(const sref& in) throw(merror_t)
+{
+  expr_t* x=new expr_t(in(1,-3));
+  xarg.push_back(x); args++;
+  if(*in=='(') x->expand(*this); else x->status=OP_PARSE;
+  swrite sw(x->result);
+  eval(sw,x,0);
+}
+
+void Env::rpush(const sref& in) throw(merror_t)
+{
+  expr_t* x=new expr_t(in(1,-3));
+  rarg.push_back(x); args++;
+  if(*in=='(') x->expand(*this); else x->status=OP_PARSE;
+}
+
+///////////////////////////////////////////////////////////
+
+static int indent(sref& p) {
+  if(cset_newl.test(p.front())) { p=p.right_first_not_of(cset_ws); return 1; }
+  else return 0;
+}
+
+static int backindent(sref& p) {
+  if(cset_newl.test(p.leftand_last_not_of(cset_spaces).back())) {
+    p=p.leftand_last_not_of(cset_ws); return 1;
+  }
+  else return 0;
+}
+
+static int pastsemi(sref& p) {
+  int s=p.find_not_of(cset_spaces);
+  if(s>=0&&p[s]==';') return indent(p=p.adv(s+1)); else return 0;
+}
+
+static int past_func(const sref& in) throw(merror_t)
+{
+  sref e=getname(in.popf()),p=in.adv(e);
+  return p.adv(past_args(p))-in;
+}
+
+static int parse_func(mstream& out,Env& env,const sref& in,int& run) throw(merror_t)
+{
+  run=0; sref e=getname(in),p=in.adv(e);
+  mstring name;
+  swrite sw(name);
+  env.eval(sw,e,0);
+  if(env.is_arg(name)) {
+    //if(count_args(p)) THROW("htc: expected no argument after "<<name);
+    if(env.up) env.up->parg(out,atoi(name)-1);
+    return p-in;
+  }
+  int inbegend=0;
+  if(name==begin_tag) {
+    sref next=p.right_first_not_of(cset_ws);
+    int s=skip_braces(next);
+    if(s>0) { name=next(1,s-2); p=next.adv(s); inbegend=1; }
+  }
+  tok_t* tok=env.toks->get(name);
+  if(!tok) { if(!(tok=env.loc.get(name))||!tok->is_func()) tok=0; }
+  if(!tok) return 0;
+  if(!tok->is_runnable()) {
+    //if(count_args(p)) THROW("htc: expected no argument after "<<name);
+    if(env.is_clear(tok)) out<<tok->body;
+    return p-in;
+  }
+  runnable_t* ftok=(runnable_t*)tok;
+  if(env.is_clear(ftok)) {
+    p=p.adv(parse_args(env,ftok,p,inbegend));
+    run=1; env.eval(out,ftok,1);
+  }
+  else p=p.adv(past_args(p));
+  return p-in;
+}
+
+void Env::parse(mstream& out,const sref& in) throw(merror_t)
+{
+  static const charset sensors=escaped|cset_newl|'\\';
+  epilog.clear();
+  int s,run;
+  sref p=in;
+  indent(p);
+  backindent(p);
+  sref e=p;
+  while(*p) {
+    switch(*p) {
+    case ';':
+    case '}':
+    case ']':
+      out.put(*p);
+      p=p.popf();
+      break;
+    case '%':
+      if(p-e>0) { out.put(*p); p=p.popf(); }
+      else e=p=p.past_nl().right_first_not_of(cset_ws);
+      break;
+    case '\r':
+      p=p.popf();
+      break;
+    case '\n':
+      out.put(*p); p=p.popf();
+      if(cset_newl.test(*p.right_first_not_of(cset_spaces))) out<<para;
+      e=p=p.right_first_not_of(cset_ws);
+      break;
+    case '{':
+      if(mod&tok_t::PUBLIC){
+        if((s=skip_braces(p))>0) {
+          eval(out,p(1,s-2),0);
+          if(pastsemi(p=p.adv(s))) e=p;
+        }
+      }
+      else { out.put(*p); p=p.popf(); }
+      break;
+    case '[':
+      if(mod&tok_t::PUBLIC){
+        if((s=skip_indices(p))>0) {
+          expr(out,p(1,s-2));
+          if(pastsemi(p=p.adv(s))) e=p;
+        }
+      }
+      else { out.put(*p); p=p.popf(); }
+      break;
+    case '$':
+      if(mod&tok_t::PUBLIC){
+        if((s=skip_dollars(p))>0) {
+          latex_env(*this).expr(out,p(1,s-2));
+          if(pastsemi(p=p.adv(s))) e=p;
+        }
+      }
+      else { out.put(*p); p=p.popf(); }
+      break;
+    case '\\':
+      p=p.popf();
+      if(p.empty()) out.put('\\');
+      else if(escaped.test(*p)) { out.put(*p); p=p.popf(); }
+      else {
+        if((s=parse_func(out,*this,p,run))>0) { if(pastsemi(p=p.adv(s))) e=p; }
+        else out.put('\\');
+      }
+      break;
+    default:
+      if((s=p.find_of(sensors))>=0) { out<<p.left(s); p=p.adv(s); }
+      else { out<<p; p.clear(); }
+      break;
+    }
+  }
+  out<<epilog;
+}
+
+void Env::parse(mstream& out,expr_t* x) throw(merror_t)
+{
+  if(x->status&OP_PARSE) parse(out,x->expr);
+  else x->eval(out,*this,OP_ALL);
+}
+
+///////////////////////////////////////////////////////////
+
+void Env::eval(mstream& out,const sref& in,int child) throw(merror_t)
+{
+  Env nenv(*this); if(child) nenv.up=this;
+  nenv.parse(out,in);
+}
+
+void Env::eval(mstream& out,expr_t* x,int child) throw(merror_t)
+{
+  Env nenv(*this); if(child) nenv.up=this;
+  nenv.parse(out,x);
+}
+
+void Env::eval(mstream& out,runnable_t* ftok,int child) throw(merror_t)
+{
+  if(child&&!check_arg(*ftok)) THROW("htc: bad number of args; expected "<<*ftok);
+  if(ftok->is_binary()) ((binary_t*)ftok)->func(out,*this);
+  else if(ftok->is_func()) eval(out,&((func_t*)ftok)->x,child);
+  else THROW("htc: unknown runnable");
+}
+
+//////////////////////////////////////////////////////
+
+int Env::split(sref& first,sref& rest) throw(merror_t)
+{
+  int s;
+  rest=rest.right_first_not_of(cset_ws);
+  if(*rest=='\\') {
+    first=rest.left(past_func(rest));
+    rest=rest.adv(first);
+  }
+  else if(spec.test(*rest)) {
+    first=rest.left_first_not_of(spec);
+    rest=rest.adv(first);
+  }
+  else if((s=skip_quotes(rest))>0||(s=skip_braces(rest))>0) {
+    first=rest.left(s);
+    rest=rest.adv(first);
+  }
+  else if((s=skip_para(rest))>0) {
+    first=rest(1,s-2);
+    rest=rest.right(s);
+  }
+  else {
+    first=getlocal(rest);
+    rest=rest.adv(first);
+  }
+  return first.nempty();
+}
+
+void Env::term(mstream& out,expr_t* x) throw(merror_t)
+{
+  if(x->expr.empty()) x->status=0;
+  else if(*x->expr=='\"') { out<<x->expr(1,-3); x->status=0; }
+  else if(*x->expr=='{') { eval(out,x->expr(1,-3),0); x->status=0; }
+  else if(x->expr.find_not_of(cset_real)<0) { out<<x->expr; x->status=0; }
+  else if(*x->expr=='\\') {
+    sref p=x->expr.popf();
+    if(p.empty()) { out.put('\\'); x->status=0; }
+    else if(escaped.test(*p)) { out.put(*p); x->status=0; }
+    else {
+      int run;
+      if(parse_func(out,*this,p,run)>0) x->status=run?OP_LOCAL:OP_GLOBAL;
+      else { out.put('\\')<<x->expr; x->status=OP_NINIT; }
+    }
+  }
+  else {
+    mstring name;
+    swrite sw(name);
+    eval(sw,x->expr,0);
+    out<<gloc(name);
+    x->status=OP_LOCAL;
+  }
+}
+
+///////////////////////////////////////////////////////////////////
+
+int latex_env::split(sref& first,sref& rest) throw(merror_t)
+{
+  int s;
+  rest=rest.right_first_not_of(cset_ws);
+  if(*rest=='\\') {
+    first=rest.left(past_func(rest));
+    rest=rest.adv(first);
+  }
+  else if(spec.test(*rest)) {
+    first=rest.left_first_not_of(spec);
+    rest=rest.adv(first);
+  }
+  else if((s=skip_braces(rest))>0||(s=skip_para(rest))>0||(s=skip_indices(rest))>0) {
+    first=rest.left(s);
+    rest=rest.adv(first);
+  }
+  else {
+    first=rest.left_first_of(specws);
+    rest=rest.adv(first);
+  }
+  return first.nempty();
+}
+
+void latex_env::term(mstream& out,expr_t* x) throw(merror_t)
+{
+  if(x->expr.empty()) x->status=0;
+  else if(*x->expr=='\\') { eval(out,x->expr,0); x->status=0; }
+  else if(*x->expr=='{') { eval(out,x->expr(1,-3),0); x->status=0; }
+  else if(*x->expr=='('||*x->expr=='[') {
+    out.put(x->expr.front());
+    expr(out,x->expr(1,-3));
+    out.put(x->expr.back());
+    x->status=0;
+  }
+  else { out<<x->expr; x->status=0; }
+}