Add conditional statements parsing

src/include/parser.h

@@ -14,7 +14,9 @@ Instruction -> Statement | ExprStatement; | Expr; | ;
 
 Statement ->
     | { Prog }
+    | If (Expr) Instruction
     | If (Expr) Instruction Else Instruction
+
 ExprStatement -> 
     | Type ParIdentifier = Expr // AssignedDeclaration
     | Type ParIdentifier // Declaration
@@ -74,7 +76,9 @@ enum class NodeType {
     LIncr, //                 -> ++ParIdentifier 
     RIncr, //                 -> ParIdentifier++
     LDecr, //                 -> --ParIdentifier
-    RDecr //                  -> ParIdentifier--
+    RDecr, //                 -> ParIdentifier--
+    If, //                    -> If (Expr) Instruction
+    IfElse //                 -> If (Expr) Instruction Else Instruction
 };
 
 struct InnerNode;
@@ -127,6 +131,11 @@ public:
 */
 Node parse(vector<Token> tokens);
 
+/**
+ * Parse something derivated from Prog
+*/
+ParseReturn parse_prog(vector<Token> tokens);
+
 /**
  * Parse something derivated from Instruction
 */

src/parser.cpp

@@ -12,7 +12,7 @@ CodePosition null_pos = {
 };
 
 
-const char* _node_names[] = {"Prog", "Epsilon", "AssignedDeclaration", "Declaration", "Plus", "Minus", "Mult", "Div", "Mod", "UnaryMinus", "UnaryPlus", "Assignment", "LIncr", "RIncr", "LDecr", "RDecr"};
+const char* _node_names[] = {"Prog", "Epsilon", "AssignedDeclaration", "Declaration", "Plus", "Minus", "Mult", "Div", "Mod", "UnaryMinus", "UnaryPlus", "Assignment", "LIncr", "RIncr", "LDecr", "RDecr", "If", "IfElse"};
 void _debug_print_tree(const Node& node, int depth, const string& prefix = "") {
     if (holds_alternative<InnerNode>(node)) {
         const InnerNode& innerNode = get<InnerNode>(node);
@@ -57,12 +57,25 @@ Node parse(vector<Token> tokens) {
         throw SyntaxError("Input must not be empty", null_pos);
     }
 
+    ParseReturn ret = parse_prog(tokens);
 
-    // At least 1 instruction
-    ParseReturn ret = parse_instruction(tokens);
-    tokens = ret.tokens;
+    if (ret.tokens.size() != 0) {
+        CodePosition pos = ret.tokens.back().pos;
+        throw SyntaxError("Unable to parse", pos);
+    }
 
-    Node node = ret.node;
+    return ret.node;
+}
+
+
+ParseReturn parse_prog(vector<Token> tokens) {
+    vector<Node> children;
+    InnerNode epsilon_node = {
+        .type=NodeType::Epsilon,
+        .children=children,
+        .pos=null_pos
+    };
+    Node node = epsilon_node;
 
     try {
         while (tokens.size() != 0) {
@@ -70,6 +83,9 @@ Node parse(vector<Token> tokens) {
             tokens = ret.tokens;
             
             if (!holds_alternative<InnerNode>(ret.node) || get<InnerNode>(ret.node).type != NodeType::Epsilon) {
+                if (holds_alternative<InnerNode>(node) && get<InnerNode>(node).type == NodeType::Epsilon) {
+                    node = ret.node; // Remove base epsilon node
+                } else {
                     InnerNode new_node = {
                         .type=NodeType::Prog,
                         .children={node, ret.node},
@@ -78,13 +94,16 @@ Node parse(vector<Token> tokens) {
                     node = new_node;
                 }
             }
-        return node;
-    } catch (const ParseException& pex) {
-        CodePosition pos = tokens.back().pos;
-        throw SyntaxError("Unable to parse", pos);
         }
+    } catch (const ParseException& pex) {}
+
+    return {
+        .node=node,
+        .tokens=tokens
+    };
 }
 
+
 ParseReturn parse_instruction(vector<Token> tokens) {
     try { //* Instruction -> Statement
         ParseReturn ret = parse_statement(tokens);
@@ -140,9 +159,95 @@ ParseReturn parse_instruction(vector<Token> tokens) {
 }
 
 ParseReturn parse_statement(vector<Token> tokens) {
-    (void)tokens;
-    // Aucune règle
+    if (tokens.size() < 2) // 'If' / 'For' '(' at least
         throw ParseException();
+
+    switch (tokens.back().type) {
+        case TokenType::If: {
+            CodePosition pos = tokens.back().pos;
+
+            tokens.pop_back();
+            if (tokens.back().type != TokenType::LParenthese) // Opening (
+                throw SyntaxError("Missing '('", tokens.back().pos);
+
+            tokens.pop_back();
+            ParseReturn ret = parse_expr(tokens); // Expr
+            
+            int nb_tok = ret.tokens.size(); // Closing )
+            if (nb_tok == 0 || ret.tokens.back().type != TokenType::RParenthese)
+                throw SyntaxError(
+                    "Missing ')'",
+                    nb_tok == 0 ? tokens.back().pos : ret.tokens.back().pos
+                );
+
+            ret.tokens.pop_back();
+            tokens = ret.tokens;
+            Node expr = ret.node;
+
+            ret = parse_instruction(tokens); // Instruction1
+            tokens = ret.tokens;
+            Node instruction1 = ret.node;
+
+            if (tokens.size() == 0 || tokens.back().type != TokenType::Else) { //* -> If (Expr) Instruction
+                InnerNode node = {
+                    .type=NodeType::If,
+                    .children={expr, instruction1},
+                    .pos=pos
+                };
+                return {
+                    .node=node,
+                    .tokens=tokens
+                };
+            }
+
+            tokens.pop_back(); // Else
+            ret = parse_instruction(tokens); // Instruction2
+            tokens = ret.tokens;
+            Node instruction2 = ret.node;
+
+            InnerNode node = {
+                .type=NodeType::IfElse,
+                .children={expr, instruction1, instruction2},
+                .pos=pos
+            };
+            return {
+                .node=node,
+                .tokens=tokens
+            };
+        }
+        case TokenType::LCurlyBracket: {
+            tokens.pop_back();
+            
+            ParseReturn ret = parse_prog(tokens);
+            if ( // No expression parsed, the next token is not a '}'
+                    holds_alternative<InnerNode>(ret.node) &&
+                    get<InnerNode>(ret.node).type == NodeType::Epsilon &&
+                    tokens.back().type != TokenType::RCurlyBracket
+                )
+                throw SyntaxError(
+                    "Invalid Syntax. Missing ';' ?",
+                    tokens.back().pos
+                );
+            
+            int nb_tok = ret.tokens.size();
+            if (nb_tok == 0 || ret.tokens.back().type != TokenType::RCurlyBracket)
+                throw SyntaxError(
+                    "Missing '}'",
+                    nb_tok == 0 ? tokens.back().pos : ret.tokens.back().pos
+                );
+
+            tokens = ret.tokens;
+            tokens.pop_back();
+
+            return {
+                .node=ret.node,
+                .tokens=tokens
+            };
+
+        }
+        default:
+            throw ParseException();
+    }
 }
 
 ParseReturn parse_expr_statement(vector<Token> tokens) {

src/tokenize.cpp

@@ -109,6 +109,16 @@ vector<Token> tokenize(vector<string> input, int initial_line) {
                 tokens.emplace_back(token);
                 j += m.str().length();
             }
+            else if (str.starts_with("if")) {
+                Token token = { .type = TokenType::If, .pos = pos };
+                tokens.emplace_back(token);
+                j += 2;
+            }
+            else if (str.starts_with("else")) {
+                Token token = { .type = TokenType::Else, .pos = pos };
+                tokens.emplace_back(token);
+                j += 4;
+            }
             else if (regex_search(str, m, IDENTIFIER_REGEX, regex_constants::match_continuous)) {
                 Token token = {
                     .type = TokenType::Identifier,
@@ -188,16 +198,6 @@ vector<Token> tokenize(vector<string> input, int initial_line) {
                 tokens.emplace_back(token);
                 j += 1;
             }
-            else if (str.starts_with("if")) {
-                Token token = { .type = TokenType::If, .pos = pos };
-                tokens.emplace_back(token);
-                j += 2;
-            }
-            else if (str.starts_with("else")) {
-                Token token = { .type = TokenType::Else, .pos = pos };
-                tokens.emplace_back(token);
-                j += 4;
-            }
             else if (isspace(str[0])) {
                 j += 1;
             }