Const-correct parser.

git-svn-id: http://svn.drobilla.net/resp/resp@323 ad02d1e2-f140-0410-9f75-f8b11f17cedd

4 files changed, 13 insertions, 14 deletions

diff --git a/src/parse.cpp b/src/parse.cpp
index 420a8ea..43fb681 100644
--- a/src/parse.cpp
+++ b/src/parse.cpp
@@ -49,7 +49,7 @@ eat_char(Cursor& cur, istream& in, const char character)
 	THROW_IF(c != character, cur, (format("expected `%1%'") % character).str());
 }
 
-static AST*
+static const AST*
 read_string(Cursor& cur, istream& in)
 {
 	Cursor loc = cur;
@@ -83,10 +83,10 @@ read_line_comment(Cursor& cur, istream& in)
 	while (read_char(cur, in) != '\n') {}
 }
 
-static AST*
+static const AST*
 read_list(PEnv& penv, Cursor& cur, istream& in)
 {
-	List<ATuple, AST> list;
+	List<ATuple, const AST> list;
 
 	eat_char(cur, in, '(');
 	while (true) {
@@ -101,7 +101,7 @@ read_list(PEnv& penv, Cursor& cur, istream& in)
 	assert(false);
 }
 
-static AST*
+static const AST*
 read_special(Cursor& cur, istream& in)
 {
 	eat_char(cur, in, '#');
@@ -120,7 +120,7 @@ read_special(Cursor& cur, istream& in)
 	assert(false);
 }
 
-static AST*
+static const AST*
 read_number(Cursor& cur, istream& in)
 {
 	Cursor loc = cur;
@@ -139,7 +139,7 @@ read_number(Cursor& cur, istream& in)
 		return new ALiteral<float>(T_FLOAT, strtod(str.c_str(), NULL), loc);
 }
 
-static AST*
+static const AST*
 read_symbol(PEnv& penv, Cursor& cur, istream& in)
 {
 	string str;
@@ -155,7 +155,7 @@ read_symbol(PEnv& penv, Cursor& cur, istream& in)
 }
 	
 /// Read an expression from @a in
-AST*
+const AST*
 read_expression(PEnv& penv, Cursor& cur, istream& in)
 {
 	while (!cin.eof()) {
@@ -175,7 +175,7 @@ read_expression(PEnv& penv, Cursor& cur, istream& in)
 			throw Error(cur, "unexpected `)'");
 		case '#':
 		{
-			AST* ret = read_special(cur, in);
+			const AST* ret = read_special(cur, in);
 			if (ret)
 				return ret;
 			break;
diff --git a/src/repl.cpp b/src/repl.cpp
index ae49b00..114ff58 100644
--- a/src/repl.cpp
+++ b/src/repl.cpp
@@ -27,7 +27,7 @@
 using namespace std;
 
 static bool
-readParseType(CEnv& cenv, Cursor& cursor, istream& is, AST*& exp, const AST*& ast)
+readParseType(CEnv& cenv, Cursor& cursor, istream& is, const AST*& exp, const AST*& ast)
 {
 	try {
 		exp = read_expression(cenv.penv, cursor, is);
@@ -81,7 +81,7 @@ callPrintCollect(CEnv& cenv, CFunc f, const AST* result, const AType* resultT, b
 int
 eval(CEnv& cenv, Cursor& cursor, istream& is, bool execute)
 {
-	AST*       exp = NULL;
+	const AST* exp = NULL;
 	const AST* ast = NULL;
 
 	typedef list<const AST*> Parsed;
@@ -160,7 +160,7 @@ eval(CEnv& cenv, Cursor& cursor, istream& is, bool execute)
 int
 repl(CEnv& cenv)
 {
-	AST*         exp        = NULL;
+	const AST*   exp        = NULL;
 	const AST*   ast        = NULL;
 	const string replFnName = cenv.penv.gensymstr("_repl");
 	while (1) {
diff --git a/src/resp.cpp b/src/resp.cpp
index 9e959f5..e745455 100644
--- a/src/resp.cpp
+++ b/src/resp.cpp
@@ -143,7 +143,7 @@ main(int argc, char** argv)
 			try {
 				while (is.good() && !is.eof()) {
 					Cursor loc(*f);
-					AST* exp = read_expression(cenv->penv, loc, is);
+					const AST* exp = read_expression(cenv->penv, loc, is);
 					if (!exp || (exp->to_tuple() && exp->to_tuple()->tup_len() == 1))
 						break;
 					
diff --git a/src/resp.hpp b/src/resp.hpp
index aa4d624..459e923 100644
--- a/src/resp.hpp
+++ b/src/resp.hpp
@@ -119,7 +119,7 @@ ostream& operator<<(ostream& out, const Env<K,V>& env) {
 
 struct PEnv;
 struct AST;
-AST* read_expression(PEnv& penv, Cursor& cur, std::istream& in);
+const AST* read_expression(PEnv& penv, Cursor& cur, std::istream& in);
 
 
 /***************************************************************************
@@ -528,7 +528,6 @@ AST::operator==(const AST& rhs) const
 			}
 		return false; // never reached
 	}
-
 	case T_UNKNOWN:
 	case T_STRING:
 	case T_SYMBOL: