From 08131d3e4ead2205593c9391f480289741cffa61 Mon Sep 17 00:00:00 2001
From: VaclavT <vaclavt@gmail.com>
Date: Sat, 15 May 2021 23:43:24 +0200
Subject: [PATCH] MlValue::is_string added

---
 ml.cpp | 6 +++++-
 ml.h   | 7 ++++---
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/ml.cpp b/ml.cpp
index 77792a2..2b64e98 100644
--- a/ml.cpp
+++ b/ml.cpp
@@ -168,7 +168,7 @@ std::vector<std::string> MlValue::get_used_atoms() {
 }
 
 // Is this a builtin function?
-bool MlValue::is_builtin() {
+bool MlValue::is_builtin() const {
 	return type == BUILTIN;
 }
 
@@ -176,6 +176,10 @@ bool MlValue::is_number() const {
 	return type == INT || type == FLOAT;
 }
 
+bool MlValue::is_string() const {
+	return type == STRING;
+}
+
 // Get the "truthy" boolean value of this value.
 bool MlValue::as_bool() const {
 	return type != NIL && *this != MlValue(0l);	// TODO remove 0 as false
diff --git a/ml.h b/ml.h
index e0a96b3..056276c 100644
--- a/ml.h
+++ b/ml.h
@@ -136,17 +136,18 @@ public:
 
     std::vector<std::string> get_used_atoms();
 
-    // Is this a builtin function?
-    bool is_builtin();
-
     // Apply this as a function to a list of arguments in a given environment.
     MlValue apply(std::vector<MlValue> args, MlEnvironment &env);
 
     // Evaluate this value as lisp code.
     MlValue eval(MlEnvironment &env);
 
+    bool is_builtin() const;
+
     bool is_number() const;
 
+    bool is_string() const;
+
     // Get the boolean value of this value.
     bool as_bool() const;