impl scopes more or less properly

builtins.c

@@ -1,6 +1,8 @@
 #include "lisp.h"
 
-Node *lisp_function_addition(Nodes *args) {
+Node *lisp_function_addition(Nodes *args, Scopes *scopes) {
+    (void)(scopes);
+
     if (args->count != 2) {
         printf("'+' expects two arguments!\n");
         return NULL;
@@ -20,3 +22,16 @@ Node *lisp_function_addition(Nodes *args) {
     node->as_number = a + b;
     return node;
 }
+
+Node *lisp_function_println(Nodes *args, Scopes *scopes) {
+    if (args->count != 1) {
+        printf("'+' expects one argument!\n");
+        return NULL;
+    }
+
+    Node *result = eval(&args->items[0], scopes);
+    node_print(*result);
+    printf("\n");
+
+    return result;
+}

lisp.c

@@ -1,16 +1,13 @@
 #include "lisp.h"
 
-static LispFunction globalScope[] = {
-    (LispFunction){.name = (Nob_String_View){.items = "+", .count = 1},
-                   .apply = lisp_function_addition}};
+static Scope globalScope = {0};
 
-static Node *lisp_function_lookup(Nob_String_View name) {
-    for (size_t i = 0; i < NOB_ARRAY_LEN(globalScope); i++) {
-        if (nob_sv_eq(globalScope[i].name, name)) {
-            Node *node = malloc(sizeof(Node));
-            node->kind = NODE_KIND_FUNCTION;
-            node->as_function = globalScope[i];
-            return node;
+static Node *scope_lookup(Scopes *scopes, Nob_String_View name) {
+    nob_da_foreach(Scope, scope, scopes) {
+        nob_da_foreach(ScopeObject, scopeObject, scope) {
+            if (nob_sv_eq(name, scopeObject->name)) {
+                return &scopeObject->node;
+            }
         }
     }
 
@@ -18,6 +15,44 @@ static Node *lisp_function_lookup(Nob_String_View name) {
     return NULL;
 }
 
+void build_scopes(Scopes *scopes) {
+    // clang-format off
+    Nob_String_View obj_name = (Nob_String_View){
+        .items = "+",
+        .count = 1
+    };
+    ScopeObject obj = (ScopeObject){
+        .name = obj_name,
+        .node = (Node){
+            .kind = NODE_KIND_FUNCTION,
+            .as_function = {
+                .name = obj_name,
+                .apply = lisp_function_addition
+            }
+        }
+    };
+    nob_da_append(&globalScope, obj);
+
+    obj_name = (Nob_String_View){
+        .items = "println",
+        .count = 7
+    };
+    obj = (ScopeObject){
+        .name = obj_name,
+        .node = (Node){
+            .kind = NODE_KIND_FUNCTION,
+            .as_function = {
+                .name = obj_name,
+                .apply = lisp_function_println
+            }
+        }
+    };
+    nob_da_append(&globalScope, obj);
+    // clang-format on
+
+    nob_da_append(scopes, globalScope);
+}
+
 const char *token_kind_name(TokenKind kind) {
     switch (kind) {
     case TOKEN_KIND_PAR_LEFT:
@@ -54,8 +89,8 @@ void node_print(Node node) {
         printf(")");
     } break;
     case NODE_KIND_FUNCTION: {
-        LispFunction func = node.as_function;
-        printf(SV_Fmt, SV_Arg(func.name));
+        Nob_String_View func_name = node.as_function.name;
+        printf(SV_Fmt, SV_Arg(func_name));
     } break;
     }
 }
@@ -180,15 +215,15 @@ Node *parse(Tokens *tokens) {
     return node;
 }
 
-Node *eval(Node *node) {
-    if (node == NULL)
+Node *eval(Node *node, Scopes *scopes) {
+    if (node == NULL || scopes == NULL)
         return NULL;
 
     switch (node->kind) {
     case NODE_KIND_NUMBER:
         return node;
     case NODE_KIND_SYMBOL: {
-        return lisp_function_lookup(node->as_symbol);
+        return scope_lookup(scopes, node->as_symbol);
     }
     case NODE_KIND_LIST: {
         Nodes *children = node->as_list;
@@ -196,16 +231,15 @@ Node *eval(Node *node) {
             return node;
 
         Node *head = &children->items[0];
-        Node *func_node = eval(head);
+        Node *func_node = eval(head, scopes);
 
         Nodes *args = malloc(sizeof(Nodes));
         for (size_t i = 1; i < children->count; i++) {
-            nob_da_append(args, *eval(&children->items[i]));
+            nob_da_append(args, *eval(&children->items[i], scopes));
         }
 
         if (func_node->kind == NODE_KIND_FUNCTION) {
-            LispFunction func = func_node->as_function;
-            return func.apply(args);
+            return func_node->as_function.apply(args, scopes);
         }
 
         printf("Not a function: '");

lisp.h

@@ -30,22 +30,22 @@ typedef enum e_NodeKind {
 
 typedef struct s_Node Node;
 typedef struct s_Nodes Nodes;
+typedef struct s_Scopes Scopes;
 
-typedef Node *(*lisp_function_ptr)(Nodes *args);
-typedef struct s_LispFunction {
-    Nob_String_View name;
-    lisp_function_ptr apply;
-} LispFunction;
+typedef Node *(*LispFunction)(Nodes *args, Scopes *scopes);
 
-typedef struct s_Node {
+struct s_Node {
     NodeKind kind;
     union {
         Nob_String_View as_symbol;
         Nodes *as_list;
         long long as_number;
-        LispFunction as_function;
+        struct {
+            Nob_String_View name;
+            LispFunction apply;
+        } as_function;
+    };
 };
-} Node;
 
 struct s_Nodes {
     Node *items;
@@ -53,14 +53,34 @@ struct s_Nodes {
     size_t capacity;
 };
 
+typedef struct s_ScopeObject {
+    Nob_String_View name;
+    Node node;
+} ScopeObject;
+
+// TODO: use hashtable
+typedef struct s_Scope {
+    ScopeObject *items;
+    size_t count;
+    size_t capacity;
+} Scope;
+
+struct s_Scopes {
+    Scope *items;
+    size_t count;
+    size_t capacity;
+};
+
 const char *token_kind_name(TokenKind kind);
 void node_print(Node node);
 
+void build_scopes(Scopes *scopes);
 void tokenize(Nob_String_View content, Tokens *tokens);
 Node *parse(Tokens *tokens);
-Node *eval(Node *node);
+Node *eval(Node *node, Scopes *scopes);
 
 // builtins
-Node *lisp_function_addition(Nodes *args);
+Node *lisp_function_addition(Nodes *args, Scopes *scopes);
+Node *lisp_function_println(Nodes *args, Scopes *scopes);
 
 #endif // LISP_H

main.c

@@ -37,11 +37,15 @@ int main(int argc, char **argv) {
     }
 #endif
 
+    Scopes scopes = {0};
+    build_scopes(&scopes);
+
     Node *result = parse(&tokens);
     if (result == NULL)
         return 1;
 
-    result = eval(result);
+    result = eval(result, &scopes);
+    printf("= ");
     node_print(*result);
     printf("\n");