From 577cd82071ca06b1be8c99b086e00a21a0abc7d4 Mon Sep 17 00:00:00 2001
From: Angelo D <43831545+AngeloD2022@users.noreply.github.com>
Date: Wed, 24 May 2023 00:19:30 -0400
Subject: [PATCH] Added syntax simplification logic to AssignmentExpression,
 LocalAssignmentExpression, and SimpleForStatement regarding shorthand
 variable updating.

---
 src/jsxer/nodes/AssignmentExpression.cpp      | 19 +++++++++++++++-
 src/jsxer/nodes/LocalAssignmentExpression.cpp | 19 +++++++++++++++-
 src/jsxer/nodes/SimpleForStatement.cpp        | 22 ++++++++++++++++---
 3 files changed, 55 insertions(+), 5 deletions(-)

diff --git a/src/jsxer/nodes/AssignmentExpression.cpp b/src/jsxer/nodes/AssignmentExpression.cpp
index fff4e94..9bbfbc9 100644
--- a/src/jsxer/nodes/AssignmentExpression.cpp
+++ b/src/jsxer/nodes/AssignmentExpression.cpp
@@ -12,7 +12,24 @@ namespace jsxer::nodes {
         if (shorthand) {
             auto expr = std::dynamic_pointer_cast<BinaryExpression>(expression);
             string value_assigned = literal.empty() ? expr->get_op() : literal;
-            return variable->to_string() + ' ' + expr->get_op_name() + "= " + value_assigned;
+            string op = expr->get_op_name();
+
+            string result = variable->to_string();
+
+            bool is_negative = value_assigned[0] == '-';
+
+            // attempt to simplify the shorthand update expression with + and -...
+            if (op == "+" || op == "-") {
+                if (is_negative) {
+                    value_assigned = value_assigned.substr(1);
+                    op = op == "+" ? "-" : "+";
+                }
+                if (value_assigned == "1") {
+                    return result + op + op;
+                }
+            }
+            return result + ' ' + op + "= " + value_assigned;
+
         } else {
             string value_assigned = literal.empty() ? expression->to_string() : literal;
             return variable->to_string() + " = " + value_assigned;
diff --git a/src/jsxer/nodes/LocalAssignmentExpression.cpp b/src/jsxer/nodes/LocalAssignmentExpression.cpp
index 131d6b9..7064af2 100644
--- a/src/jsxer/nodes/LocalAssignmentExpression.cpp
+++ b/src/jsxer/nodes/LocalAssignmentExpression.cpp
@@ -19,8 +19,25 @@ namespace jsxer::nodes {
 
             // FIXME: i have a bad feeling about this one...
             string value_assigned = literal.empty() ? b->get_op() : literal;
+            string op = b->get_op_name();
 
-            result += var_name + ' ' + b->get_op_name() + "= " + value_assigned;
+            result += var_name;
+
+            bool is_negative = value_assigned[0] == '-';
+
+            // attempt to simplify the shorthand update expression with + and -...
+            if (op == "+" || op == "-") {
+                if (is_negative) {
+                    value_assigned = value_assigned.substr(1);
+                    op = op == "+" ? "-" : "+";
+                }
+                if (value_assigned == "1") {
+                    return result + op + op;
+                }
+            }
+            return result + ' ' + op + "= " + value_assigned;
+
+//            result += var_name + ' ' + b->get_op_name() + "= " + value_assigned;
         } else {
             string value_assigned = literal.empty() ? expression->to_string() : literal;
             result += var_name + " = " + value_assigned;
diff --git a/src/jsxer/nodes/SimpleForStatement.cpp b/src/jsxer/nodes/SimpleForStatement.cpp
index aea1bef..10fb835 100644
--- a/src/jsxer/nodes/SimpleForStatement.cpp
+++ b/src/jsxer/nodes/SimpleForStatement.cpp
@@ -18,8 +18,24 @@ namespace jsxer::nodes {
         result += "for (var ";
         result += varname + " = " + iteratorInitial + "; ";
         result += varname + ' ' + comparisonOperator + ' ' + upperBound->to_string() + "; ";
-        result += varname + " += " + stepSize;
-        result += ") { \n" + bodyInfo.create_body() + '}';
+
+        result += varname;
+
+        // attempt to simplify the update expression...
+        string op = "+";
+        bool is_negative = stepSize[0] == '-';
+        string value_assigned = is_negative ? stepSize.substr(1) : stepSize;
+
+        // we want to alter the operator to be functionally equivalent, such that the step value can be unsigned...
+        if (is_negative)
+            op = "-";
+        if (value_assigned == "1")
+            result += op + op;
+        else
+            result += " " + op + "= " + value_assigned;
+
+        result += ") {\n" + bodyInfo.create_body() + "\n}";
+
         return result;
     }
-}
\ No newline at end of file
+}