From: Alexei Sheplyakov <varg@theor.jinr.ru>
Date: Sun, 14 Sep 2008 02:24:29 +0000 (+0400)
Subject: Use the new parser in the ex(const string&, lst&) ctor.
X-Git-Tag: release_1-5-0~59^2~4
X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=95bec2b8af126412b2e27b51e6bfd8d9ab18d5d7

Use the new parser in the ex(const string&, lst&) ctor.

Note: this is certainly not the optimal way to use the parser. It's provided
for backward compatibility only.
---

diff --git a/ginac/Makefile.am b/ginac/Makefile.am
index 17b272f2..2614c457 100644
--- a/ginac/Makefile.am
+++ b/ginac/Makefile.am
@@ -16,6 +16,7 @@ libginac_la_SOURCES = add.cpp archive.cpp basic.cpp clifford.cpp color.cpp \
   parser/builtin_fcns.cpp \
   parser/lexer.cpp \
   parser/lexer.hpp \
+  parser/parser_compat.cpp \
   parser/debug.hpp
   
 libginac_la_LDFLAGS = -version-info $(LT_VERSION_INFO) -release $(LT_RELEASE)
diff --git a/ginac/ex.cpp b/ginac/ex.cpp
index 377b15b4..7becb3e1 100644
--- a/ginac/ex.cpp
+++ b/ginac/ex.cpp
@@ -553,17 +553,6 @@ basic & ex::construct_from_double(double d)
 	return *bp;
 }
 
-ptr<basic> ex::construct_from_string_and_lst(const std::string &s, const ex &l)
-{
-	set_lexer_string(s);
-	set_lexer_symbols(l);
-	ginac_yyrestart(NULL);
-	if (ginac_yyparse())
-		throw (std::runtime_error(get_parser_error()));
-	else
-		return parsed_ex.bp;
-}
-	
 //////////
 // static member variables
 //////////
diff --git a/ginac/parser/parser_compat.cpp b/ginac/parser/parser_compat.cpp
new file mode 100644
index 00000000..d0723eed
--- /dev/null
+++ b/ginac/parser/parser_compat.cpp
@@ -0,0 +1,49 @@
+/// @file parser_compat.cpp Parser interface compatible with the old
+///       (bison/flex based) parser.
+#include "ex.h"
+#include "idx.h"
+#include "lst.h"
+#include "parser.hpp"
+#include <string>
+#include <iostream>
+
+namespace GiNaC
+{
+static symtab make_symtab(const ex& l);
+
+ptr<basic> ex::construct_from_string_and_lst(const std::string &s, const ex &l)
+{
+	static const bool strict = true;
+	symtab syms = make_symtab(l);
+	parser reader(syms, strict); 
+	ex parsed_ex = reader(s);
+	return parsed_ex.bp;
+}
+
+static std::string get_symbol_name(const ex & s);
+
+static symtab make_symtab(const ex& l)
+{
+	symtab syms;
+	if (is_exactly_a<lst>(l)) {
+		for (std::size_t i = 0; i < l.nops(); i++) {
+			const ex &o = l.op(i);
+			if (is_a<symbol>(o) || (is_a<idx>(o) && is_a<symbol>(o.op(0))))
+				syms[get_symbol_name(o)] = o;
+		}
+	}
+	return syms;
+}
+
+static std::string get_symbol_name(const ex & s)
+{
+	if (is_a<symbol>(s))
+		return ex_to<symbol>(s).get_name();
+	else if (is_a<idx>(s) && is_a<symbol>(s.op(0)))
+		return ex_to<symbol>(s.op(0)).get_name();
+	else
+		throw (std::invalid_argument("get_symbol_name(): unexpected expression type"));
+}
+
+}
+