From 03deaf70dde4181373c2c3c44e8bbb0ba6718b41 Mon Sep 17 00:00:00 2001
From: tomsmeding <hallo@tomsmeding.nl>
Date: Tue, 8 Sep 2015 19:14:27 +0200
Subject: make scopes ACTUALLY WORK nicely

---
 functions.cpp | 40 +++++++++++++++++++++++++++++-----------
 1 file changed, 29 insertions(+), 11 deletions(-)

diff --git a/functions.cpp b/functions.cpp
index 9655e5a..8bd4053 100644
--- a/functions.cpp
+++ b/functions.cpp
@@ -1,11 +1,12 @@
 #include <iostream>
 #include <fstream>
 #include <unordered_map>
-#include <unordered_set>
+// #include <unordered_set>
 #include <vector>
 #include <stack>
 #include <string>
 #include <functional>
+#include <cmath>
 #include <unistd.h>
 #include <fcntl.h>
 
@@ -18,7 +19,10 @@ extern char **g_argv;
 
 #define BUILTIN_GUARD_STACKSIZE(nm,sz) {if(S.size()<(sz))throw string("Builtin '" nm "' needs " #sz " stack item")+(sz==1?"":"s");}
 
-stack<unordered_set<string>> scopestack;
+stack<unordered_map<string,pair<Stackitem,bool>>> scopestack;
+//Each stack frame contains the variables local to the stack frame. The bool is
+//whether it was already present in the previous frame, and the Stackitem
+//is the value held by the previous frame, if any.
 
 //please extern this shit with const!
 unordered_map<string,function<void(vector<Stackitem>&,unordered_map<string,Stackitem>&)>> builtins={
@@ -213,11 +217,17 @@ unordered_map<string,function<void(vector<Stackitem>&,unordered_map<string,Stack
 		if(!name.isstr)throw string("Second argument to 'store' not a string");
 		auto it=variables.find(name.strval);
 		bool exists=it!=variables.end();
+		if(scopestack.size()&&scopestack.top().find(name.strval)==scopestack.top().end()){
+			if(exists)
+				scopestack.top()[name.strval]={move(variables[name.strval]),true};
+			else
+				scopestack.top()[name.strval]={Stackitem(),false};
+		}
 		//insert_or_assign is C++17 sadly
-		/*if(exists)variables.insert(it,make_pair(name.strval,move(S.back())));
-		else*/ variables[name.strval]=move(S.back());
+		/*if(exists)variables.insert_or_assign(it,make_pair(name.strval,move(S.back())));
+		else variables[name.strval]=move(S.back());*/
+		variables[name.strval]=move(S.back());
 		S.pop_back();
-		if(scopestack.size()&&!exists)scopestack.top().insert(name.strval);
 	}},
 	{"gstore",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
 		BUILTIN_GUARD_STACKSIZE("gstore",2)
@@ -241,17 +251,19 @@ unordered_map<string,function<void(vector<Stackitem>&,unordered_map<string,Stack
 		variables[name.strval].intval=0;
 	}},
 	{"enterscope",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
-		//cerr<<"scope enter"<<endl;
+		BUILTIN_GUARD_STACKSIZE("enterscope",0)
 		scopestack.emplace();
 	}},
 	{"leavescope",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
+		BUILTIN_GUARD_STACKSIZE("leavescope",0)
 		if(scopestack.size()<1)throw string("Scope stack empty while requesting scope leave");
-		//cerr<<"scope leave: ";
-		for(const string &varname : scopestack.top()){
-			variables.erase(varname);
-			//cerr<<varname<<' ';
+		for(const pair<string,pair<Stackitem,bool>> &var : scopestack.top()){
+			if(var.second.second){
+				variables[var.first]=move(var.second.first);
+			} else {
+				variables.erase(var.first);
+			}
 		}
-		//cerr<<endl;
 		scopestack.pop();
 	}},
 	//positive n: roll OFF top to bottom; negative n: roll off bottom ONTO top
@@ -323,6 +335,12 @@ unordered_map<string,function<void(vector<Stackitem>&,unordered_map<string,Stack
 		S.back().intval=(int)S.back().strval[0];
 		S.back().strval="";
 	}},
+	{"sleep",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
+		BUILTIN_GUARD_STACKSIZE("sleep",1)
+		if(S.back().isstr)throw string("Argument to 'sleep' not a number");
+		usleep(S.back().intval);
+		S.pop_back();
+	}},
 	{"stackdump",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
 		BUILTIN_GUARD_STACKSIZE("stackdump",0)
 		cerr<<"STACKDUMP: ";
-- 
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