added nil, true, false and parenthesis expressions

3 files changed, 42 insertions, 12 deletions

diff --git a/colm/colm.lm b/colm/colm.lm
index 0b581e20..9668b041 100644
--- a/colm/colm.lm
+++ b/colm/colm.lm
@@ -13,6 +13,10 @@ lex
 	token ELSE / 'else' /
 	token IN / 'in' /
 
+	token NIL / 'nil' /
+	token TRUE / 'true' /
+	token FALSE / 'false' /
+
 	token id / 
 		( 'a' .. 'z' | 'A' .. 'Z' | '_' ) .
 		( 'a' .. 'z' | 'A' .. 'Z' | '0' .. '9' | '_' ) *
@@ -161,11 +165,18 @@ def expr_stmt
 	[CodeExpr: code_expr]
 
 def code_expr
+	[CodeFactor: code_factor]
+
+def code_factor
 	[Number: number]
 |	[Lit: lit]
 |	[VarRef: var_ref POPEN CodeExprList: code_expr* PCLOSE]
 |	[VarRef: var_ref]
-|	[PARSE opt_capture TypeRef: type_ref opt_field_init accumulate]
+|	[Parse: PARSE opt_capture TypeRef: type_ref opt_field_init accumulate]
+|	[Nil: NIL]
+|	[True: TRUE]
+|	[False: FALSE]
+|	[POPEN ParenCodeExpr: code_expr PCLOSE]
 
 def type_ref
 	[RegionQual: region_qual Id: id OptRepeat: opt_repeat]
diff --git a/colm/loadsrc.cc b/colm/loadsrc.cc
index 97e46475..c9d5d5c7 100644
--- a/colm/loadsrc.cc
+++ b/colm/loadsrc.cc
@@ -350,36 +350,36 @@ LangVarRef *LoadSource::walkVarRef( var_ref varRef )
 	return langVarRef;
 }
 
-LangExpr *LoadSource::walkCodeExpr( code_expr codeExpr )
+LangExpr *LoadSource::walkCodeFactor( code_factor codeFactor )
 {
 	LangExpr *expr = 0;
-	if ( codeExpr.VarRef() != 0 ) {
-		var_ref varRef = codeExpr.VarRef();
+	if ( codeFactor.VarRef() != 0 ) {
+		var_ref varRef = codeFactor.VarRef();
 		LangVarRef *langVarRef = walkVarRef( varRef );
 		LangTerm *term;
-		if ( codeExpr.CodeExprList() == 0 ) {
+		if ( codeFactor.CodeExprList() == 0 ) {
 			term = LangTerm::cons( internal, LangTerm::VarRefType, langVarRef );
 		}
 		else {
-			ExprVect *exprVect = walkCodeExprList( codeExpr.CodeExprList() );
+			ExprVect *exprVect = walkCodeExprList( codeFactor.CodeExprList() );
 			term = LangTerm::cons( internal, langVarRef, exprVect );
 		}
 
 		expr = LangExpr::cons( term );
 	}
-	else if ( codeExpr.Number() != 0 ) {
-		String number = codeExpr.Number().text().c_str();
+	else if ( codeFactor.Number() != 0 ) {
+		String number = codeFactor.Number().text().c_str();
 		LangTerm *term = LangTerm::cons( InputLoc(), LangTerm::NumberType, number );
 		expr = LangExpr::cons( term );
 	}
-	else if ( codeExpr.Lit() != 0 ) {
-		String lit = codeExpr.Lit().text().c_str();
+	else if ( codeFactor.Lit() != 0 ) {
+		String lit = codeFactor.Lit().text().c_str();
 		LangTerm *term = LangTerm::cons( internal, LangTerm::StringType, lit );
 		expr = LangExpr::cons( term );
 	}
-	else {
+	else if ( codeFactor.Parse() != 0 ) {
 		/* The type we are parsing. */
-		type_ref typeRefTree = codeExpr.TypeRef();
+		type_ref typeRefTree = codeFactor.TypeRef();
 		TypeRef *typeRef = walkTypeRef( typeRefTree );
 
 		LangVarRef *varRef = LangVarRef::cons( internal, new QualItemVect, String("stdin") );
@@ -392,9 +392,26 @@ LangExpr *LoadSource::walkCodeExpr( code_expr codeExpr )
 
 		expr = parseCmd( internal, false, objField, typeRef, 0, list );
 	}
+	else if ( codeFactor.Nil() != 0 ) {
+		expr = LangExpr::cons( LangTerm::cons( internal, LangTerm::NilType ) );
+	}
+	else if ( codeFactor.True() != 0 ) {
+		expr = LangExpr::cons( LangTerm::cons( internal, LangTerm::TrueType ) );
+	}
+	else if ( codeFactor.False() != 0 ) {
+		expr = LangExpr::cons( LangTerm::cons( internal, LangTerm::FalseType ) );
+	}
+	else if ( codeFactor.ParenCodeExpr() != 0 ) {
+		expr = walkCodeExpr( codeFactor.ParenCodeExpr() );
+	}
 	return expr;
 }
 
+LangExpr *LoadSource::walkCodeExpr( code_expr codeExpr )
+{
+	return walkCodeFactor( codeExpr.CodeFactor() );
+}
+
 LangStmt *LoadSource::walkExprStmt( expr_stmt &exprStmt )
 {
 	LangStmt *stmt;
diff --git a/colm/loadsrc.h b/colm/loadsrc.h
index 2d46fe2e..5f374890 100644
--- a/colm/loadsrc.h
+++ b/colm/loadsrc.h
@@ -55,6 +55,7 @@ struct lang_stmt_list;
 struct elsif_list;
 struct elsif_clause;
 struct optional_else;
+struct code_factor;
 
 struct LoadSource
 :
@@ -91,6 +92,7 @@ struct LoadSource
 	LangStmt *walkElsifList( elsif_list elsifList );
 	LangStmt *walkStatement( statement Statement );
 	LangStmt *walkPrintStmt( print_stmt &PrintStmt );
+	LangExpr *walkCodeFactor( code_factor codeFactor );
 	LangStmt *walkExprStmt( expr_stmt &ExprStmt );
 	QualItemVect *walkQual( qual &Qual );
 	LangVarRef *walkVarRef( var_ref varRef );