precedence stuff yay!

src/parser/parser.cpp

@@ -127,12 +127,13 @@ namespace Solstice {
     Node Parser::parseExpr(TT type) {
         auto left = getPreviousNode(output);
         if (!left.has_value()) {
-            throw std::runtime_error("Expecting expression on left of '+'");
+            throw std::runtime_error("Expecting expression on left of expression");
         }
+        Precedence leftPrec = getNodePrecedence(*left);
         Precedence precedence = getTokenPrecedence(Token(type));
         auto right = parseOneNode(precedence);
         if (!right.has_value()) {
-            throw std::runtime_error("Expecting expression on right of '+'");
+            throw std::runtime_error("Expecting expression on right of expression");
         }
 
         NodeType nodeType;
@@ -142,7 +143,19 @@ namespace Solstice {
             nodeType = tokToNodeType[type];
         }
 
-        return Node(nodeType, {*left, *right});    
+        if (leftPrec >= precedence) {
+            // enclose the left node inside this node 
+            return Node(nodeType, {*left, *right});    
+        } else {
+            // steal the right child of the left node and use it as our left value,
+            // then enclose ourself inside the left node
+            auto newLeft = left->children[1];
+            Node us{nodeType, {newLeft, *right}};
+
+            left->children[1] = us;
+            return *left;
+        }
+
     }
 
     Node Parser::parseLiteral() {
@@ -171,10 +184,36 @@ namespace Solstice {
         return Node(*id);
     }
 
+    Precedence Parser::getNodePrecedence(const Node& node) {
+        switch (node.type) {
+            case NodeType::Root:
+                return Precedence::Root;
+            case NodeType::Literal:
+            case NodeType::Identifier:
+                return Precedence::Identifier;
+            case NodeType::FunctionBind:
+            case NodeType::Bind:
+            case NodeType::Set:
+                return Precedence::Set;
+            case NodeType::Lambda:
+            case NodeType::FunctionCall:
+                return Precedence::Identifier;
+            case NodeType::Add:
+            case NodeType::Subtract:
+                return Precedence::Add;
+            case NodeType::Multiply:
+            case NodeType::Divide:
+                return Precedence::Multiply;
+            case NodeType::Equal:
+            case NodeType::NotEqual:
+            case NodeType::GreaterThan:
+            case NodeType::LesserThan:
+                return Precedence::Compare;
+
+        }
+    }
+
     Precedence Parser::getTokenPrecedence(const Token& token) {
-        static size_t braceCount = 0;
-        static size_t bracketCount = 0;
-        static size_t spikyBracketCount = 0;
         switch (token.type) {
             case TT::OpenCurly: {
                 braceCount++;
@@ -244,7 +283,7 @@ namespace Solstice {
         if (!next.has_value()) {
             return {};
         }
-        if (getTokenPrecedence(*next) >= precedence) {
+        if (getTokenPrecedence(*next) <= precedence) {
             return {};
         }
         consume();