yummy

documentation/lang/Grammar.md

@@ -2,18 +2,21 @@
 Basically just an outline of how to type things out and how things work syntactically.
 $$
 \begin{align}
-    [\text{prog}] &\to [\text{stmt}]^* \\
+    [\text{Prog}] &\to [\text{Stmt}]^* \\
-    [\text{stmt}]^* &\to
+    [\text{Stmt}]^* &\to
     \begin{cases}
-        \text{exit}([\text{expr}]); \\
+        \text{exit}([\text{Expr}]); \\
-        \text{var}\space\text{ident} = [\text{expr}]; \\
+        \text{var}\space\text{ident} = [\text{Expr}]; \\
+        \text{if}\ ([\text{Expr}])\ [\text{Scope}] \\
+        [\text{Scope}] \\
     \end{cases} \\
-    [\text{expr}] &\to
+    [\text{Expr}] &\to
     \begin{cases}
-        \text{[Term]}
+        \text{[Term]} \\
         \text{[BinExpr]} \\
     \end{cases} \\
-    [\text{BinExpr}]
+    [\text{Scope}] &\to \{[\text{Stmt}]^*\} \\
+    [\text{BinExpr}] &\to
     \begin{cases}
         [\text[{Expr}]!] &prec=3\\
         [\text[{Expr}] ^ \text{[Expr]}] &prec=2\\

examples/compact/exitall.x

@@ -1,4 +1,11 @@
 var x = 1 + 2 * 3;
+{
+    var z = 2;
+    var y = 2;
+}
 var y = x - 3;
 var z = (3*5) / 3;
-exit(y + z);
+if (x) {
+    exit(y + z);
+}
+exit (1);

src/error.hxx

@@ -4,6 +4,7 @@
 #include <optional>
 
 namespace err {
+    // Compiler Errors
     inline void syntax(std::optional<std::string> err) {
         std::cerr << "xlang: \033[1;31merror:\033[0m \033[1;37mexpected '" << err.value() << "'\033[0m" << std::endl;
     }
@@ -40,6 +41,12 @@ namespace err {
         std::cerr << "xlang: \033[1;31merror:\033[0m \033[1;37mundeclared varible '" << err.value() << "'\033[0m" << std::endl;
     }
 
+    inline void scope() {
+        std::cerr << "xlang: \033[1;31merror:\033[0m \033[1;37minvalid scope\033[0m" << std::endl;
+    }
+
+
+    // Operator errors
     inline void nofile() {
         std::cerr << "xlang: \033[1;31merror:\033[0m \033[1;37mno input files\033[0m" << std::endl;
     }
@@ -47,4 +54,6 @@ namespace err {
     inline void help() {
         std::cerr << "xlang: \033[1;31merror:\033[0m \033[1;37mhelp no implemented... just... uhm... look at main.cxx?\033[0m" << std::endl;
     }
+
+    
 }

src/generation.hxx

@@ -3,7 +3,6 @@
 #include <optional>
 #include <vector>
 #include <cassert>
-#include <map>
 
 #include "parser.hxx"
 
@@ -13,6 +12,14 @@ public:
         // Erm!!!
     }
 
+    void gen_scope(const node::Scope* scope) {
+        begin_scope();
+        for (const node::Stmt* stmt : scope->stmts) {
+            gen_stmt(stmt);
+        }
+        end_scope();
+    }
+
     void gen_stmt(const node::Stmt* stmt) {
         struct StmtVisitor { // Visiting the homies
             Generator* gen;
@@ -24,13 +31,28 @@ public:
             }
 
             void operator()(const node::StmtVar* stmt_var) {
-                if (gen->m_vars.contains(stmt_var->ident.value.value())) {
+                auto it = std::find_if(gen->m_vars.cbegin(), gen->m_vars.cend(), [&](const Var& var){return var.name == stmt_var->ident.value.value();});
+                if (it != gen->m_vars.cend()) {
                     err::redefine(stmt_var->ident.value.value());
                     exit(EXIT_FAILURE);
                 }
-                gen->m_vars.insert({stmt_var->ident.value.value(), Var {.stack_loc = gen->m_stack_size}});
+                gen->m_vars.push_back({.name = stmt_var->ident.value.value(), .stack_loc = gen->m_stack_size});
                 gen->gen_expr(stmt_var->expr);
             }
+
+            void operator()(const node::StmtIf* stmt_if) const {
+                gen->gen_expr(stmt_if->expr);
+                gen->pop("rax");
+                std::string label = gen->create_label();
+                gen->m_output << "    test rax, rax\n";
+                gen->m_output << "    jz " << label << "\n";
+                gen->gen_scope(stmt_if->scope);
+                gen->m_output << "\n" << label << ":\n";
+            }
+
+            void operator()(const node::Scope* scope) {
+                gen->gen_scope(scope);
+            }
         };
 
         StmtVisitor visitor {.gen = this};
@@ -47,13 +69,13 @@ public:
             }
 
             void operator()(const node::TermIdent* term_ident) const {
-                if (!gen->m_vars.contains(term_ident->ident.value.value())) {
+                auto it = std::find_if(gen->m_vars.cbegin(), gen->m_vars.cend(), [&](const Var& var){return var.name == term_ident->ident.value.value();});
+                if (it == gen->m_vars.cend()) {
                     err::undeclared(term_ident->ident.value.value());
                     exit(EXIT_FAILURE);
                 }
-                const auto& var = gen->m_vars.at(term_ident->ident.value.value());
                 std::stringstream offset;
-                offset << "QWORD [rsp + " << (gen->m_stack_size - var.stack_loc - 1) * 8 << "]";
+                offset << "QWORD [rsp + " << (gen->m_stack_size - (*it).stack_loc - 1) * 8 << "]";
                 gen->push(offset.str());
             }
             void operator()(const node::TermParen* term_paren) const {
@@ -139,6 +161,26 @@ public:
     }
 private:
 
+    void begin_scope() {
+        m_scopes.push_back(m_vars.size());
+    }
+
+    void end_scope(){
+        size_t pop_count = m_vars.size() - m_scopes.back();
+        m_output << "    add rsp, " << pop_count * 8 << "\n";
+        m_stack_size -= pop_count;
+        for (int i = 0; i < pop_count; i++) {
+            m_vars.pop_back();
+        }
+        m_scopes.pop_back();
+    }
+
+    std::string create_label() {
+        std::stringstream ss;
+        ss << ".label" << m_label_count++;
+        return ss.str();
+    }
+
     void push(const std::string& reg) {
         m_output << "    push " << reg << "\n";
         m_stack_size++;
@@ -150,11 +192,14 @@ private:
     }
 
     struct Var {
+        std::string name;
         size_t stack_loc;
     };
 
     const node::Prog m_prog;
     std::stringstream m_output;
     size_t m_stack_size = 0;
-    std::map<std::string, Var> m_vars {};
+    std::vector<Var> m_vars {};
+    std::vector<size_t> m_scopes {};
+    int m_label_count = 0;
 };

src/parser.hxx

@@ -10,6 +10,7 @@
 
 namespace node {
     struct Expr;
+    struct Stmt;
 
     struct TermIntLit {
         Token int_lit;
@@ -55,6 +56,10 @@ namespace node {
         std::variant<Term*, BinExpr*> var;
     };
 
+    struct Scope {
+        std::vector<Stmt*> stmts;
+    };
+
     struct StmtExit {
         Expr* expr;
     };
@@ -64,8 +69,13 @@ namespace node {
         Expr* expr;
     };
 
+    struct StmtIf {
+        Expr* expr;
+        Scope* scope;
+    };
+
     struct Stmt {
-        std::variant<StmtExit*, StmtVar*> var;
+        std::variant<StmtExit*, StmtVar*, StmtIf*, Scope*> var;
     };
 
     struct Prog {
@@ -163,7 +173,7 @@ public:
                 sub->lhs = expr_lhs2;
                 sub->rhs = expr_rhs.value();
                 expr->var = sub;
-            } else if (op.type == TokenType::slash) {
+            } else if (op.type == TokenType::fslash) {
                 auto div = m_allocator.alloc<node::BinExprDiv>();
                 expr_lhs->var = term_lhs.value();
                 expr_lhs2->var = expr_lhs->var;
@@ -179,6 +189,18 @@ public:
         return expr_lhs;
     }
 
+    std::optional<node::Scope*> parse_scope() {
+        if (!try_consume(TokenType::open_curly).has_value()) {
+            return {};
+        }
+         auto scope = m_allocator.alloc<node::Scope>();
+        while (auto stmt = parse_stmt()) {
+            scope->stmts.push_back(stmt.value());
+        }
+        try_consume(TokenType::close_curly, "}");
+        return scope;
+    }
+
     std::optional<node::Stmt*> parse_stmt() {
         if (peek().has_value() && peek().value().type == TokenType::exit && peek(1).has_value() && peek(1).value().type == TokenType::open_paren) {
             consume();
@@ -187,7 +209,7 @@ public:
             if (auto node_expr = parse_expr()) {
                 stmt_exit->expr = node_expr.value();
             } else {
-                err::expression({});
+                err::expression("exit");
                 exit(EXIT_FAILURE);
             }
 
@@ -214,6 +236,34 @@ public:
             auto stmt = m_allocator.alloc<node::Stmt>();
             stmt->var = stmt_var;
             return stmt;
+        } else if (peek().has_value() && peek().value().type == TokenType::open_curly) {
+            if (auto scope = parse_scope()) {
+                auto stmt = m_allocator.alloc<node::Stmt>();
+                stmt->var = scope.value();
+                return stmt;
+            } else {
+                err::scope();
+                exit(EXIT_FAILURE);
+            }
+        } else if (auto if_ = try_consume(TokenType::if_)) {
+            try_consume(TokenType::open_paren, "(");
+            auto stmt_if = m_allocator.alloc<node::StmtIf>();
+            if (auto expr = parse_expr()) {
+                stmt_if->expr = expr.value();
+            } else {
+                err::expression("if");
+                exit(EXIT_FAILURE);
+            }
+            try_consume(TokenType::close_paren, ")");
+            if (auto scope = parse_scope()) {
+                stmt_if->scope = scope.value();
+            } else {
+                err::scope();
+                exit(EXIT_FAILURE);
+            }
+            auto stmt = m_allocator.alloc<node::Stmt>();
+            stmt->var = stmt_if;
+            return stmt;
         } else {
             return {};
         }

src/tokenization.hxx

@@ -5,6 +5,7 @@
 #include <sstream>
 #include <optional>
 #include <vector>
+#include <string>
 
 #include "error.hxx"
 
@@ -19,16 +20,21 @@ enum class TokenType {
     equals,
     plus,
     star,
-    slash,
+    fslash,
     minus,
     carrot,
     excl,
+    open_curly,
+    close_curly,
+    open_bracket,
+    close_bracket,
+    if_,
 };
 
 std::optional<int> bin_prec(TokenType type) {
     switch (type) {
         case TokenType::star:
-        case TokenType::slash:
+        case TokenType::fslash:
             return 1;
         case TokenType::plus:
         case TokenType::minus:
@@ -51,7 +57,6 @@ public:
     inline std::vector<Token> tokenize() {
         std::vector<Token> tokens;
         std::string buffer;
-
         while (peek().has_value()) {
             if (std::isalpha(peek().value())) {
                 buffer.push_back(consume());
@@ -64,6 +69,9 @@ public:
                 } else if (buffer == "var") {
                     tokens.push_back({.type = TokenType::var});
                     buffer.clear();
+                } else if (buffer == "if") {
+                    tokens.push_back({.type = TokenType::if_});
+                    buffer.clear();
                 } else {
                     tokens.push_back({.type = TokenType::ident, .value = buffer});
                     buffer.clear();
@@ -75,41 +83,32 @@ public:
                 }
                 tokens.push_back({.type = TokenType::int_lit, .value = buffer});
                 buffer.clear();
-            } else if (peek().value() == '(') {
-                consume();
-                tokens.push_back({.type = TokenType::open_paren});
-            } else if (peek().value() == ')') {
-                consume();
-                tokens.push_back({.type = TokenType::close_paren});
-            } else if (peek().value() == ';') {
-                consume();
-                tokens.push_back({.type = TokenType::semi});
-            } else if (peek().value() == '=') {
-                consume();
-                tokens.push_back({.type = TokenType::equals});
-            } else if (peek().value() == '+') {
-                consume();
-                tokens.push_back({.type = TokenType::plus});
-            } else if (peek().value() == '*') {
-                consume();
-                tokens.push_back({.type = TokenType::star});
-            } else if (peek().value() == '-') {
-                consume();
-                tokens.push_back({.type = TokenType::minus});
-            } else if (peek().value() == '/') {
-                consume();
-                tokens.push_back({.type = TokenType::slash});
-            } else if (peek().value() == '^') {
-                consume();
-                tokens.push_back({.type = TokenType::carrot});
-            } else if (peek().value() == '!') {
-                consume();
-                tokens.push_back({.type = TokenType::excl});
             } else if (std::isspace(peek().value())) {
                 consume();
-            }  else {
+            } else {
-                err::unknowntype(buffer);
+                char c = peek().has_value() ? *peek() : -1;
-                exit(EXIT_FAILURE);
+                if (c != -1) {
+                    switch(c) {
+                        case '(': tokens.push_back({.type = TokenType::open_paren}); break;
+                        case ')': tokens.push_back({.type = TokenType::close_paren}); break;
+                        case ';': tokens.push_back({.type = TokenType::semi}); break;
+                        case '=': tokens.push_back({.type = TokenType::equals}); break;
+                        case '+': tokens.push_back({.type = TokenType::plus}); break;
+                        case '*': tokens.push_back({.type = TokenType::star}); break;
+                        case '-': tokens.push_back({.type = TokenType::minus}); break;
+                        case '/': tokens.push_back({.type = TokenType::fslash}); break;
+                        case '^': tokens.push_back({.type = TokenType::carrot}); break;
+                        case '!': tokens.push_back({.type = TokenType::excl}); break;
+                        case '{': tokens.push_back({.type = TokenType::open_curly}); break;
+                        case '}': tokens.push_back({.type = TokenType::close_curly}); break;
+                        case '[': tokens.push_back({.type = TokenType::open_bracket}); break;
+                        case ']': tokens.push_back({.type = TokenType::close_bracket}); break;
+                        default:
+                            err::unknowntype(buffer);
+                            exit(EXIT_FAILURE);
+                    }
+                    consume();
+                }
             } 
         }
         // Return mah shit
@@ -130,6 +129,10 @@ private:
         return m_src.at(m_index++);
     }
 
+    constexpr unsigned int string_hash(const char* str, int h = 0) {
+        return !str[h] ? 5381 : (string_hash(str, h + 1) * 33) ^ str[h];
+    }
+
     const std::string m_src;
     size_t m_index = 0;
 };