Initial

1 files changed, 68 insertions, 0 deletions

diff --git a/prelude.cpp b/prelude.cpp
new file mode 100644
index 0000000..eb503b0
--- /dev/null
+++ b/prelude.cpp
@@ -0,0 +1,68 @@
+#include <iostream>
+#include <sstream>
+#include <string>
+#include "error.h"
+#include "prelude.h"
+
+using namespace std;
+
+
+Environment prelude;
+
+const AST afterBootstrap=AST(R"RAW(
+(do
+	(def '. \f \g \x (f (g x)))
+	(def 'flip \f \a \b (f b a))
+	(def 'id \x x)
+	(def 'const \x \y x)
+	(def 'print (. putstr repr)))
+)RAW");
+
+class PreludeInit{
+public:
+	PreludeInit(Environment &intoEnv){
+		intoEnv.define("repr",AST::makeNative([](const AST &ast) -> AST {
+			stringstream ss;
+			ss<<ast;
+			String res=ss.str();
+			return AST::makeString(res);
+		}));
+
+		intoEnv.define("putstr",AST::makeNative([](const AST &ast) -> AST {
+			if(ast.type!=AST::Type::string){
+				throw TypeError("Argument to 'putstr' is not a String");
+			}
+			cout<<ast.strval<<endl;
+			return AST();
+		}));
+
+		intoEnv.define("def",[](Environment &env,const AST &arg1) -> AST {
+			return AST::makeNative([&env,arg1](const AST &arg2) -> AST {
+				if(arg1.type!=AST::Type::name){
+					throw TypeError("First argument to 'def' is not a Name");
+				}
+				env.define(arg1.nameval,arg2);
+				return AST();
+			});
+		});
+
+		intoEnv.define("do",AST::makeNative([](const AST&) -> AST {
+			throw logic_error("'do' stub called; this should not happen");
+		}));
+
+		intoEnv.define2("+",[](Environment&,const AST &arg1,const AST &arg2) -> AST {
+			if(arg1.type!=arg2.type){
+				throw TypeError("Unequal types in '+'");
+			}
+			if(arg1.type==AST::Type::number){
+				return AST::makeNumber(arg1.numval+arg2.numval);
+			} else if(arg1.type==AST::Type::string){
+				return AST::makeString(arg1.strval+arg2.strval);
+			} else {
+				throw TypeError("Arguments to '+' neither Number nor String");
+			}
+		});
+
+		intoEnv.run(afterBootstrap);
+	}
+} preludeInit(prelude);