ast_printer: fix children printing

- add scope ids for debug purposes
 - add children to parent on Scope.createChild
 - types: add validation of if's condition expr type
 - types: add scopes to ifs

src/ast_printer.zig

@@ -370,7 +370,7 @@ fn prettyType(typ: SymbolUnderlyingType) []const u8 {
 }
 
 pub fn printScope(scope: *Scope, ident: usize) void {
-    print(ident, "scope at addr {}\n", &scope);
+    print(ident, "scope '{}' at addr {}\n", scope.id, &scope);
 
     var it = scope.env.iterator();
     while (it.next()) |kv| {
@@ -378,7 +378,7 @@ pub fn printScope(scope: *Scope, ident: usize) void {
     }
 
     for (scope.children.toSlice()) |child| {
-        printScope(scope, ident + 1);
+        printScope(child, ident + 1);
     }
 }
 

src/comp_ctx.zig

@@ -39,8 +39,9 @@ pub const Scope = struct {
     children: ScopeList,
 
     allocator: *std.mem.Allocator,
+    id: ?[]const u8 = null,
 
-    pub fn create(allocator: *std.mem.Allocator, parent: ?*Scope) !*Scope {
+    pub fn create(allocator: *std.mem.Allocator, parent: ?*Scope, id: ?[]const u8) !*Scope {
         var scope = try allocator.create(Scope);
 
         scope.* = Scope{
@@ -48,12 +49,15 @@ pub const Scope = struct {
             .env = Environment.init(allocator),
             .children = ScopeList.init(allocator),
             .allocator = allocator,
+            .id = id,
         };
         return scope;
     }
 
-    pub fn createChild(self: *@This()) !*Scope {
+    pub fn createChild(self: *@This(), id: ?[]const u8) !*Scope {
-        return try @This().create(self.allocator, self);
+        var child = try @This().create(self.allocator, self, id);
+        try self.children.append(child);
+        return child;
     }
 
     pub fn deinit(self: *const @This()) void {
@@ -135,12 +139,14 @@ pub const CompilationContext = struct {
     }
 
     /// Create a new scope out of the current one and set it as the current.
-    pub fn bumpScope(self: *@This()) !void {
+    pub fn bumpScope(self: *@This(), scope_id: ?[]const u8) !void {
         if (self.current_scope == null) {
             @panic("can't bump scope from null");
         }
 
-        var child = try self.current_scope.?.createChild();
+        std.debug.warn("==scope bump== '{}'\n", scope_id);
+
+        var child = try self.current_scope.?.createChild(scope_id);
         self.current_scope = child;
     }
 
@@ -155,6 +161,14 @@ pub const CompilationContext = struct {
             @panic("can't dump scope from null");
         }
 
+        const parent_id: ?[]const u8 = if (self.current_scope.?.parent == null) null else self.current_scope.?.parent.?.id;
+
+        std.debug.warn(
+            "==scope dump== {} to {}\n",
+            self.current_scope.?.id,
+            parent_id,
+        );
+
         self.current_scope = self.current_scope.?.parent;
     }
 

src/types.zig

@@ -88,6 +88,14 @@ pub const TypeSolver = struct {
         }
     }
 
+    pub fn expectSymUnType(self: *@This(), symbol_type: comp.SymbolUnderlyingType, wanted_type: comp.SymbolUnderlyingTypeEnum) !void {
+        var actual_type = comp.SymbolUnderlyingTypeEnum(symbol_type);
+        if (actual_type != wanted_type) {
+            std.debug.warn("Expected {}, got {}\n", wanted_type, actual_type);
+            return CompileError.TypeError;
+        }
+    }
+
     // TODO make return type optional and so, skip exprs that
     // fail to be fully resolved, instead of returning CompileError
     pub fn resolveExprType(
@@ -235,17 +243,21 @@ pub const TypeSolver = struct {
 
             // If create two scopes for each branch of the if
             .If => |ifstmt| {
-                _ = try self.resolveExprType(ctx, ifstmt.condition);
+                var cond_type = try self.resolveExprType(ctx, ifstmt.condition);
+                try self.expectSymUnType(cond_type, .Bool);
 
-                // TODO assert condition's type is bool
+                try ctx.bumpScope("if_then");
 
-                // TODO bump-dump scope
                 for (ifstmt.then_branch.toSlice()) |then_stmt| {
                     try self.stmtPass(ctx, then_stmt);
                 }
 
+                ctx.dumpScope();
+
                 if (ifstmt.else_branch) |else_branch| {
-                    // TODO bump-dump scope
+                    try ctx.bumpScope("if_else");
+                    defer ctx.dumpScope();
+
                     for (else_branch.toSlice()) |else_stmt| {
                         try self.stmtPass(ctx, else_stmt);
                     }
@@ -287,7 +299,7 @@ pub const TypeSolver = struct {
                 self.setErrContext("function {}", decl.func_name.lexeme);
                 var ret_type = self.resolveGlobalType(ctx, decl.return_type.lexeme);
 
-                std.debug.warn("resolved fn {} type: {}\n", decl.func_name.lexeme, ret_type);
+                std.debug.warn("start analysis of fn {} ret_type: {}\n", decl.func_name.lexeme, ret_type);
 
                 var parameters = comp.TypeList.init(self.allocator);
                 for (decl.params.toSlice()) |param| {
@@ -298,7 +310,7 @@ pub const TypeSolver = struct {
 
                 // for a function, we always create a new root scope for it
                 // and force-set it into the current context
-                var scope = try comp.Scope.create(self.allocator, null);
+                var scope = try comp.Scope.create(self.allocator, null, "function");
                 errdefer scope.deinit();
 
                 // we must always start from a null current scope,
@@ -314,15 +326,6 @@ pub const TypeSolver = struct {
                 ctx.dumpScope();
                 std.debug.assert(ctx.current_scope == null);
 
-                // TODO scopes: down scope
-
-                // TODO symbols and scope resolution, that's
-                // its own can of worms
-                var symbols = comp.SymbolTable.init(self.allocator);
-
-                // TODO go through body, resolve statements, expressions
-                // and everything else
-
                 if (ret_type != null and parameters.len == decl.params.len) {
                     try ctx.insertFn(decl, ret_type.?, parameters, scope);
                 }