From 8c87404928e86741a9c409c04e276f73a3e3b00a Mon Sep 17 00:00:00 2001
From: "[GPL]Ed" <sanduedi309@gmail.com>
Date: Mon, 29 May 2023 14:50:23 +0000
Subject: [PATCH] Change substitution rules for arrays (better
 security+optimization), add array lexical scoping

---
 doc/man1/let.1      |  9 ++++++---
 examples/unique.zrc | 29 +++++++++++++++++++++++++++++
 src/config.hpp      |  2 +-
 src/dispatch.hpp    | 24 ++++++++++++++++++------
 src/subst.hpp       |  4 ++--
 5 files changed, 56 insertions(+), 12 deletions(-)
 create mode 100755 examples/unique.zrc

diff --git a/doc/man1/let.1 b/doc/man1/let.1
index debff14..f2f4153 100644
--- a/doc/man1/let.1
+++ b/doc/man1/let.1
@@ -6,15 +6,18 @@ let \- Use a lexical scoping block
 .SH DESCRIPTION
 The first argument of
 .I let
-must be a list representing the variables that will return to their original value after executing the second argument, which is a "code block".
+must be a list representing the variables that will return to their original value after executing the second argument, which is a "code block". If a variable's name begins with `A,...`, then the utility stores a backup of the associative array of the same name.
 .SH EXAMPLE
 .EX
 	set var1 = value
 	set var2 = value
-	let {var1 var2} {
+	set arr(1) = x
+	set arr(2) = y
+	let {var1 var2 A,arr} {
+		array delete arr
 		set var1 = a
 		set var2 = b
 	}
 	#The original values were preserved!
-	echo $var1 $var2
+	echo $var1 $var2 $arr(1)
 .EE
diff --git a/examples/unique.zrc b/examples/unique.zrc
new file mode 100755
index 0000000..ea3108d
--- /dev/null
+++ b/examples/unique.zrc
@@ -0,0 +1,29 @@
+#!/usr/lib/zrc/bin/zrc
+alias str string
+
+fn unique {
+	let {count line A,map} {
+		set count = 0
+		until {[read line]} {
+			switch $map($line) {
+				case '' {
+					inc count
+					set map($line) = 1
+				}
+				case 1 {
+					inc count -1
+					set map($line) = 2
+				}	
+			}
+		}
+		echo $count
+	}
+}
+
+if {$argc == 2} {
+	unique
+} else {
+	for {set i = 2} {$i < $argc} {inc i} {
+		unique < $argv($i)
+	}
+}
diff --git a/src/config.hpp b/src/config.hpp
index f496d9d..3db2acc 100644
--- a/src/config.hpp
+++ b/src/config.hpp
@@ -3,4 +3,4 @@
 
 static std::string errmsg         = "syntax error: ";
 static std::string default_prompt = "zrc% ";
-static std::string ver            = "zrc v0.2";
+static std::string ver            = "zrc v0.3";
diff --git a/src/dispatch.hpp b/src/dispatch.hpp
index 63da58f..530ad71 100644
--- a/src/dispatch.hpp
+++ b/src/dispatch.hpp
@@ -493,18 +493,30 @@ Command(let) {
 		syntax_error("<var list> <block>");
 
 	WordList vars;
-	std::map<std::string, Variable> hm;
+	std::map<std::string, Array> a_hm_bak;
+	std::map<std::string, Scalar> s_hm_bak;
 	/* empty */ {
 		NullFin;
 		vars = tokenize(argv[1], fin);
 	}
-	for (std::string const& str : vars.wl)
-		hm[str] = getvar(str);
+	for (std::string str : vars.wl) {
+		if (str[0] == 'A' && str[1] == ',') {
+			str.erase(0, 2);
+			a_hm_bak[str] = a_hm[str];
+		} else {
+			s_hm_bak[str] = getvar(str);
+		}
+	}
 	eval(argv[2]);
-	for (std::string const& str : vars.wl)
-		setvar(str, hm[str]);
+	for (std::string& str : vars.wl) {
+		if (str[0] == 'A' && str[1] == ',') {
+			str.erase(0, 2);
+			a_hm[str] = a_hm_bak[str];
+		} else {
+			setvar(str, s_hm_bak[str]);
+		}
+	}
 	NoReturn;
-	
 }
 
 /** Sourcing scripts into current session **/
diff --git a/src/subst.hpp b/src/subst.hpp
index 9ba9b00..906c41f 100644
--- a/src/subst.hpp
+++ b/src/subst.hpp
@@ -117,13 +117,13 @@ str_subst(std::string& str)
 					tmp1 += str[i];
 					if (str[i] == '(') {
 						ITERATE_PAREN('(',')');
-						str_subst(tmp2);
 						tmp1 += tmp2+")";
 						arr_ok = true;
 						break;
 					}
 				}
-				str_subst(tmp1);
+				if (!arr_ok)
+					str_subst(tmp1);
 				res += get_var(tmp1);
 				if (!arr_ok)
 					--i;