From ec773c08be9721b3cc667fd4a48d8a8854517dbc Mon Sep 17 00:00:00 2001
From: Krzosa Karol <krzosa.karol@gmail.com>
Date: Thu, 26 May 2022 18:57:15 +0200
Subject: [PATCH] Add init statement to if

---
 cgenerate.cpp   | 12 ++++++++++++
 lambdas.kl      |  4 ++--
 new_ast.cpp     | 22 ++++++++++++++++++++--
 new_parse.cpp   | 25 ++++++++++++++++++++++---
 new_resolve.cpp | 15 +++++++++++++++
 5 files changed, 71 insertions(+), 7 deletions(-)

diff --git a/cgenerate.cpp b/cgenerate.cpp
index e6ec256..d31a137 100644
--- a/cgenerate.cpp
+++ b/cgenerate.cpp
@@ -208,8 +208,20 @@ gen_ast(Ast *ast){
       Ast_End();
     }
 
+    Ast_Begin(AST_INIT, Ast_Init){
+      Sym *sym = resolved_get(node);
+      gen_simple_decl(sym->type, node->ident->intern_val);
+      if(node->expr){
+        gen(" = ");
+        gen_expr(node->expr);
+      }
+      gen(";");
+      Ast_End();
+    }
+
     Ast_Begin(AST_IF, Ast_If){
       For(node->ifs){
+        if(it[0]->init) gen_ast(it[0]->init);
         if(node->ifs.is_first(it)){
           genln("if(");
           gen_expr(it[0]->expr);
diff --git a/lambdas.kl b/lambdas.kl
index f6a7acc..d1ad82e 100644
--- a/lambdas.kl
+++ b/lambdas.kl
@@ -2,8 +2,8 @@
 if_stmt :: (cond: int): int
   CONSTANT :: 10
 
-  if      cond + CONSTANT
-    return cond + CONSTANT
+  if i := cond, cond + CONSTANT
+    return i + CONSTANT
   else if cond - CONSTANT
     return cond - CONSTANT
   else
diff --git a/new_ast.cpp b/new_ast.cpp
index 39deacd..dd25d3d 100644
--- a/new_ast.cpp
+++ b/new_ast.cpp
@@ -89,6 +89,7 @@ enum Ast_Kind{
   AST_COMPOUND_ITEM,
   AST_COMPOUND,
 
+  AST_INIT,
   AST_IF,
   AST_IF_NODE,
   AST_RETURN,
@@ -167,9 +168,16 @@ struct Ast_Return: Ast{
   Ast_Expr *expr;
 };
 
+struct Ast_Init: Ast{
+  Token_Kind op;
+  Ast_Atom *ident;
+  Ast_Expr *expr;
+};
+
 struct Ast_If_Node: Ast{
   Ast_Expr  *expr ;
   Ast_Block *block;
+  Ast_Init  *init;
 };
 
 struct Ast_If: Ast{
@@ -338,9 +346,19 @@ ast_if(Token *pos, Array<Ast_If_Node *> ifs){
 }
 
 function Ast_If_Node *
-ast_if_node(Token *pos, Ast_Expr *expr, Ast_Block *block){
+ast_if_node(Token *pos, Ast_Init *init, Ast_Expr *expr, Ast_Block *block){
   AST_NEW(If_Node, AST_IF_NODE, pos);
-  result->block = block;
+  result->block    = block;
+  result->expr     = expr;
+  result->init = init;
+  return result;
+}
+
+function Ast_Init *
+ast_init(Token *pos, Token_Kind op, Ast_Atom *ident, Ast_Expr *expr){
+  AST_NEW(Init, AST_INIT, pos);
+  result->op    = op;
+  result->ident = ident;
   result->expr  = expr;
   return result;
 }
diff --git a/new_parse.cpp b/new_parse.cpp
index 40c400a..7140cdf 100644
--- a/new_parse.cpp
+++ b/new_parse.cpp
@@ -196,8 +196,27 @@ parse_block(){
       else if(token_match_keyword(keyword_if)){
         Array<Ast_If_Node *> if_nodes = {scratch};
         Ast_Expr *expr = parse_expr();
+        Ast_Init *init_val = 0;
+
+        {
+          Token *token = token_get();
+          if(token_match(TK_Colon)){
+            if(expr->kind != AST_IDENT) parsing_error(token, "Failed to parse init stmt, expected left of [:] to be a token of kind [Identifier]");
+            if(token_match(TK_Assign)){
+              Ast_Expr *value = parse_expr();
+              assert(expr->kind == AST_IDENT);
+              init_val = ast_init(token, TK_Comma, (Ast_Atom *)expr, value);
+            }
+            else not_implemented;
+
+            if(token_match(TK_Comma)){
+              expr = parse_expr();
+            }
+          }
+        }
+
         Ast_Block *block = parse_block();
-        Ast_If_Node *if_node = ast_if_node(token, expr, block);
+        Ast_If_Node *if_node = ast_if_node(token, init_val, expr, block);
         if_nodes.add(if_node);
 
         while(token_is(SAME_SCOPE) && token_is_keyword(keyword_else, 1)){
@@ -206,12 +225,12 @@ parse_block(){
           if(token_match_keyword(keyword_if)){
             Ast_Expr *expr = parse_expr();
             Ast_Block *block = parse_block();
-            Ast_If_Node *if_node = ast_if_node(token, expr, block);
+            Ast_If_Node *if_node = ast_if_node(token, 0, expr, block);
             if_nodes.add(if_node);
           }
           else{
             Ast_Block *block = parse_block();
-            Ast_If_Node *if_node = ast_if_node(token, 0, block);
+            Ast_If_Node *if_node = ast_if_node(token, 0, 0, block);
             if_nodes.add(if_node);
             break;
           }
diff --git a/new_resolve.cpp b/new_resolve.cpp
index 8b7b1ec..c676d77 100644
--- a/new_resolve.cpp
+++ b/new_resolve.cpp
@@ -212,12 +212,27 @@ eval_stmt(Ast *ast, Ast_Resolved_Type *ret){
       Ast_End();
     }
 
+    Ast_Begin(AST_INIT, Ast_Init){
+      switch(node->op){
+        case TK_Comma:{
+          Operand op = eval_expr(node->expr);
+          Sym *sym = sym_new(SYM_Var, node->ident->intern_val, op.type, node);
+          sym_insert(sym);
+        }break;
+        invalid_default_case;
+      }
+      Ast_End();
+    }
+
     Ast_Begin(AST_IF, Ast_If){
       For(node->ifs){
         if(it[0]->expr) eval_expr(it[0]->expr);
+        if(it[0]->init) eval_stmt(it[0]->init, ret);
+        S64 scope_index = scope_push();
         For_It(it[0]->block->stmts, jt){
           eval_stmt(jt[0], ret);
         }
+        scope_pop(scope_index);
       }
       Ast_End();
     }