✨ begin blocks.

.gitignore

@@ -3,3 +3,4 @@
 *\#*
 build
 doc/build
+vgcore.*

ccm/main.c

@@ -11,9 +11,10 @@ int main(int argc, char** argv)
         module_t module;
         module_init(&module);
 
-        module_load(&module, argv[1]);
+        status = module_load(&module, argv[1]);
 
-        if (!err_is_ok(&module.err))
+
+        if (status != 0 || !err_is_ok(&module.err))
         {
             err_print_stack_trace(&module.err);
             status = 1;

doc/grammar.bnf

@@ -2,6 +2,13 @@ MODULE ::= EXPR*
 EXPR ::=
 | OR
 | ASSERT
+| DECL
+| ASSIGN
+| BEGIN
+BEGIN ::= begin BLOCK end
+BLOCK ::= EXPR*
+ASSIGN ::= (ident|INDEX) assign EXPR
+DECL ::= (var|const) ident assign EXPR
 ASSERT ::= (assert_eq|assert_ne) tuple
 OR ::= AND (or AND)*
 AND ::= EQNE (and EQNE)*
@@ -21,7 +28,7 @@ LITERAL ::=
 | opar EXPR cpar
 ARRAY ::= osquare (EXPR (comma EXPR)*)? csquare
 INDEX ::= 
-| (TUPLE|str|ARRAY) osquare (EXPR (comma EXPR)*)? csquare
+| (TUPLE|str|ident|ARRAY) osquare (EXPR (comma EXPR)*)? csquare
 TUPLE ::=
 | opar EXPR+ cpar
-BUILTIN ::= num | bool | str
+BUILTIN ::= num | bool | str | ident

lib/CMakeLists.txt

@@ -17,6 +17,7 @@ add_library(ccm_lib
     prog.c
     compiler.c
     exec.c
+    sym.c
 )
 
 set_property(TARGET ccm_lib PROPERTY C_STANDARD 99)

lib/bytecode.h

@@ -9,7 +9,8 @@ G(OP_ADD), G(OP_SUB), G(OP_USUB), G(OP_MUL), \
 G(OP_DIV), G(OP_POW), G(OP_MOD), G(OP_MK_TUPLE), \
 G(OP_ASSERT_EQ), G(OP_ASSERT_NE), G(OP_BRF), G(OP_BR), \
 G(OP_NOT), G(OP_IN), G(OP_INDEX), G(OP_EQ), G(OP_LT), \
-G(OP_GT), G(OP_MK_ARRAY)
+G(OP_GT), G(OP_MK_ARRAY), G(OP_LOCAL_STORE),  \
+G(OP_LOCAL_LOAD), G(OP_ASTORE)
 
 CCM_ENUM_H(Opcode, OPCODES);
 

lib/ccm.c

@@ -4,11 +4,14 @@
 void ccm_init(ccm_t* self)
 {
     assert(self);
+    sym_init(&self->sym);
     vec_init(&self->values);
     vec_init(&self->stack);
     vec_init(&self->globals);
     err_init(&self->err);
     self->id_counter = 0;
+
+    sym_open_scope(&self->sym);
 }
 
 void ccm_entry_free(ccm_entry_t* self)
@@ -20,6 +23,7 @@ void ccm_entry_free(ccm_entry_t* self)
 void ccm_free(ccm_t* self)
 {
     assert(self);
+    sym_free(&self->sym);
     err_free(&self->err);
     vec_free_elements(&self->values, (void*) ccm_entry_free);
     vec_free(&self->values);
@@ -332,6 +336,26 @@ CCM ccm_top(ccm_t* self, int depth)
     return (CCM) self->stack.data[self->stack.size - 1 - depth];
 }
 
+void ccm_set(ccm_t* self, CCM value, int addr)
+{
+    assert(self);
+    while (addr >= (ssize_t) self->stack.size)
+    {
+        ccm_push(self, 0);
+    }
+
+    self->stack.data[addr] = (void*) value;
+}
+
+CCM ccm_get(ccm_t* self, int addr)
+{
+    assert(self);
+    assert(addr < (ssize_t) self->stack.size);
+    assert(addr >= 0);
+
+    return (CCM) self->stack.data[addr];
+}
+
 void ccm_in(ccm_t* self)
 {
     assert(self);

lib/ccm.h

@@ -5,6 +5,7 @@
 #include "vec.h"
 #include "value.h"
 #include "err.h"
+#include "sym.h"
 
 typedef size_t CCM;
 
@@ -14,6 +15,7 @@ typedef struct {
 } ccm_entry_t;
 
 typedef struct {
+    sym_t sym;
     err_t err;
     vec_t values;
     vec_t stack;
@@ -62,6 +64,8 @@ CCM ccm_to_ref(ccm_t* self, size_t value, int line);
 void ccm_push(ccm_t* self, CCM value);
 CCM ccm_pop(ccm_t* self);
 CCM ccm_top(ccm_t* self, int depth);
+void ccm_set(ccm_t* self, CCM value, int addr);
+CCM ccm_get(ccm_t* self, int addr);
 
 void ccm_in(ccm_t* self);
 void ccm_add(ccm_t* self);

lib/commons.h

@@ -9,7 +9,7 @@
 #include <ctype.h>
 #include <assert.h>
 
-#define CCM_STRLEN 256
+#define CCM_STRLEN 4096
 #define CCM_ENUM_ENUM(X) X
 #define CCM_ENUM_STR(X) #X
 

lib/compiler.c

@@ -5,6 +5,7 @@ void compiler_init(compiler_t* self, module_t* module)
     assert(self);
     err_init(&self->err);
     self->module = module;
+    self->loc_counter = 0;
 }
 
 void compiler_free(compiler_t* self)
@@ -27,9 +28,135 @@ void compiler_compile(compiler_t* self,
     }
 
     ccm_t* ccm = &self->module->ccm;
+    sym_t* sym = &self->module->sym;
 
     switch (node->kind)
     {
+        case NODE_BLOCK: {
+
+            sym_open_scope(sym);
+            for (size_t i=0; i<node->children.size; i++)
+            {
+                compiler_compile(
+                    self, 
+                    node->children.data[i], 
+                    prog
+                );
+            }
+
+            sym_close_scope(sym);
+        } break;
+
+        case NODE_BEGIN: {
+            compiler_compile(self, node->children.data[0], prog);
+        } break;
+        case NODE_ASSIGN: {
+            node_t* target = node->children.data[0];
+            node_t* expr = node->children.data[1];
+
+            if (target->kind == NODE_INDEX) {
+                node_t* ident = target->children.data[0];
+
+                sym_entry_t const* entry = sym_try_get_value(
+                    sym,
+                    ident->value
+                );
+
+
+                if (!entry) {
+                    err_push(&self->err, ident->line,
+                             "undefined array '%s'", ident->value);
+                    return;
+                }
+
+                if (entry->is_const) {
+                    err_push(&self->err, ident->line,
+                             "cannot assign value to constant '%s'",
+                             ident->value);
+                    return;
+                }
+                compiler_compile(self, expr, prog);
+                size_t indexes_count = target->children.size - 1;
+
+                for (size_t i=1; i<target->children.size; i++) {
+                    compiler_compile(
+                        self,
+                        target->children.data[i],
+                        prog
+                    );
+                }
+
+                prog_add_instr(prog, OP_PUSH, entry->local_addr);
+                prog_add_instr(prog, OP_ASTORE, indexes_count);
+            } else {
+                compiler_compile(self, expr, prog);
+                int status =
+                    sym_try_assign(
+                        sym, 
+                        target->value, self->loc_counter
+                    );
+
+                sym_entry_t* entry = sym_try_get_value(
+                    sym, 
+                    target->value
+                );
+
+                assert(entry);
+
+                if (entry->is_const) {
+                    err_push(&self->err, target->line,
+                             "cannot assign value to constant '%s'",
+                             target->value);
+                    return;
+                }
+                if (!status)
+                {
+                    err_push(&self->err, target->line,
+                             "cannot assign value to '%s'",
+                             target->value);
+                    return;
+                }
+
+                prog_add_instr(prog, OP_LOCAL_STORE, self->loc_counter);
+
+                self->loc_counter++;
+            }
+
+        } break;
+
+        case NODE_CONSTDECL:
+        case NODE_VARDECL: {
+            node_t const* ident = node->children.data[0];
+            node_t* expr = node->children.data[1];
+
+            compiler_compile(self, expr, prog);
+            int status =
+                sym_declare(
+                    sym, ident->value,
+                    self->loc_counter,
+                    node->kind == NODE_CONSTDECL
+                );
+            assert(status);
+            prog_add_instr(prog, OP_LOCAL_STORE, self->loc_counter);
+            self->loc_counter++;
+        } break;
+
+        case NODE_IDENT: {
+            char const* name = node->value;
+            sym_entry_t const* entry = sym_try_get_value(
+                sym, 
+                name
+            );
+
+            if (!entry) {
+                err_push(&self->err, node->line,
+                         "undefined '%s'", name);
+                return;
+            }
+
+            prog_add_instr(prog, OP_LOCAL_LOAD, entry->local_addr);
+        } break;
+
         case NODE_ARRAY: {
             for (size_t i=0; i<node->children.size; i++)
             {

lib/compiler.h

@@ -11,6 +11,7 @@
 typedef struct {
     module_t* module;
     err_t err;
+    int loc_counter;
 } compiler_t;
 
 void compiler_init(compiler_t* self, module_t* module);

lib/exec.c

@@ -44,6 +44,22 @@ void exec_instr(exec_t* self,
 
     switch (op)
     {
+        case OP_LOCAL_STORE: {
+            CCM value = ccm_pop(ccm);
+            int addr = param;
+
+            ccm_set(ccm, value, addr);
+            ccm_push(ccm, value);
+            self->pc++;
+        } break;
+
+        case OP_LOCAL_LOAD: {
+            int addr = param;
+            CCM value = ccm_get(ccm, addr);
+            ccm_push(ccm, value);
+            self->pc++;
+        } break;
+
         case OP_MK_ARRAY: {
             vec_t* vec = malloc(sizeof(vec_t));
             vec_init(vec);
@@ -54,7 +70,11 @@ void exec_instr(exec_t* self,
                 vec_push(vec, ccm_to_value(ccm, element));
             }
 
-            int line  = ((value_t*) vec->data[0])->line;
+            int line = 0;
+
+            if (vec->size > 0) {
+                line = ((value_t*) vec->data[0])->line;
+            }
 
             size_t addr = ccm_store_global(
                 ccm,
@@ -80,6 +100,36 @@ void exec_instr(exec_t* self,
             self->pc++;
         } break;
 
+        case OP_ASTORE: {
+            int addr = ccm_pop(ccm);
+            CCM ccm_gaddr = ccm_get(ccm, addr);
+            int gaddr = ccm_from_ref(ccm, ccm_gaddr);
+
+            CCM ccm_target = ccm_load_global(ccm, gaddr);
+            value_t* target = ccm_to_value(ccm, ccm_target);
+
+            int indexes[param];
+            memset(indexes, 0, param * sizeof(int));
+
+            for (int i=0; i<param; i++) {
+                CCM ccm_idx = ccm_pop(ccm);
+                int idx = ccm_from_num(ccm, ccm_idx);
+                indexes[param - 1 - i] = idx;
+            }
+
+            for (int i=0; i<param-1; i++)
+            {
+                target = target->data.array->data[indexes[i]];
+            }
+
+            CCM ccm_expr = ccm_pop(ccm);
+            value_t* expr = ccm_to_value(ccm, ccm_expr);
+            target->data.array->data[indexes[param - 1]]
+                = expr;
+            ccm_push(ccm, ccm_expr);
+            self->pc++;
+        } break;
+
         case OP_INDEX: {
             CCM ccm_target = ccm_pop(ccm);
 
@@ -165,16 +215,21 @@ void exec_instr(exec_t* self,
                 CCM ccm_result = ccm_from_value(ccm, result);
 
                 if (ccm_is_array(ccm, ccm_result)) {
-                    CCM ref = ccm_to_ref(ccm,
+                    CCM ref = ccm_to_ref(
+                        ccm,
                         ccm_store_global(ccm, ccm_result),
-                                         result->line);
+                        result->line
+                    );
                     ccm_push(ccm, ref);
                 } else {
                     ccm_push(ccm, ccm_result);
                 }
 
             } else {
-                assert(0);
+                value_t const* val = ccm_to_value(ccm, ccm_target);
+                err_push(&self->err, val->line,
+                         "not an array");
+                return;
             }
 
             self->pc++;
@@ -210,9 +265,6 @@ void exec_instr(exec_t* self,
 
         case OP_ASSERT_NE:
         case OP_ASSERT_EQ: {
-            // TODO: bug here
-            // [1] == [1] -> OK
-            // assert_eq ([1], [1]) -> Failed
             CCM val = ccm_pop(ccm);
             vec_t* values = ccm_from_tuple(ccm, val);
             assert(values->size == 2);
@@ -255,6 +307,13 @@ void exec_instr(exec_t* self,
                     "assertion failed: <%s> %s <%s>",
                     lhs, operator, rhs
                 );
+            } else {
+                ccm_push(ccm,
+                         ccm_to_boolean(
+                         ccm, 1,
+                         ((value_t*) values->data[0])->line
+                         )
+                );
             }
 
             self->pc++;

lib/lexer.c

@@ -32,6 +32,7 @@ void lexer_init(lexer_t* self)
     lexer_add_text(self, "%", NODE_MOD);
     lexer_add_text(self, "[", NODE_OSQUARE);
     lexer_add_text(self, "]", NODE_CSQUARE);
+    lexer_add_text(self, "=", NODE_ASSIGN);
 }
 
 void lexer_free(lexer_t* self)
@@ -170,6 +171,10 @@ node_t* lexer_try_new_next(lexer_t* self)
         }
     }
 
+    CCM_KEYWORD("begin", NODE_BEGIN, 0);
+    CCM_KEYWORD("end", NODE_END, 0);
+    CCM_KEYWORD("var", NODE_VAR, 0);
+    CCM_KEYWORD("const", NODE_CONST, 0);
     CCM_KEYWORD("assert_eq", NODE_ASSERT_EQ, 0);
     CCM_KEYWORD("assert_ne", NODE_ASSERT_NE, 0);
     CCM_KEYWORD("true", NODE_BOOL, 1);
@@ -179,7 +184,13 @@ node_t* lexer_try_new_next(lexer_t* self)
     CCM_KEYWORD("not", NODE_NOT, 0);
     CCM_KEYWORD("in", NODE_IN, 0);
 
+    if ( (node = lexer_try_new_ident(self)) )
+    {
+        return node;
+    }
+
     if (self->cursor < (ssize_t) strlen(self->source))
+
     {
         str_t s;
         str_init(&s);
@@ -441,3 +452,47 @@ node_t* lexer_try_new_str(lexer_t* self)
     return node;
 }
 
+node_t* lexer_try_new_ident(lexer_t* self)
+{
+    int cursor = self->cursor;
+    str_t value;
+    str_init(&value);
+
+    if (cursor >= (ssize_t) strlen(self->source)
+    || !lexer_is_ident_start(self, self->source[cursor]))
+    {
+        return NULL;
+    }
+
+    str_push(&value, self->source[cursor]);
+    cursor++;
+
+    while (cursor < (ssize_t) strlen(self->source)
+    && lexer_is_ident(self, self->source[cursor]))
+    {
+        str_push(&value, self->source[cursor]);
+        cursor++;
+    }
+
+    node_t* node = malloc(sizeof(node_t));
+    node_init(node, NODE_IDENT, value.value, self->line);
+    str_free(&value);
+    self->cursor = cursor;
+    return node;
+}
+
+int lexer_is_ident_start(lexer_t* lexer, char c)
+{
+    assert(lexer);
+
+    return isalpha(c)
+    || c == '_'
+    || c == '?'
+    || c == '!';
+}
+
+int lexer_is_ident(lexer_t* lexer, char c)
+{
+    return isdigit(c)
+    || lexer_is_ident_start(lexer, c);
+}

lib/lexer.h

@@ -54,4 +54,8 @@ node_t* lexer_try_new_text(lexer_t* self,
 
 node_t* lexer_try_new_num(lexer_t* self);
 node_t* lexer_try_new_str(lexer_t* self);
+node_t* lexer_try_new_ident(lexer_t* self);
+int lexer_is_ident_start(lexer_t* lexer, char c);
+int lexer_is_ident(lexer_t* lexer, char c);
+
 #endif

lib/module.c

@@ -10,12 +10,16 @@ void module_init(module_t* self)
     prog_init(&self->prog);
     err_init(&self->err);
     ccm_init(&self->ccm);
+    sym_init(&self->sym);
+    sym_open_scope(&self->sym);
 }
 
 void module_free(module_t* self)
 {
     assert(self);
     
+    sym_free(&self->sym);
+
     if (self->source)
     {
         free(self->source);
@@ -30,6 +34,7 @@ int module_load(module_t* self, char const* path)
 {
     assert(self);
     assert(path);
+    int status = 0;
 
     if (module_load_source(self, path) != 0)
     {
@@ -45,25 +50,33 @@ int module_load(module_t* self, char const* path)
     parser_init(&parser, &lexer);
 
     node_t* ast = parser_try_new_parse(&parser);
-    
     if (!err_is_ok(&lexer.err) || !err_is_ok(&parser.err))
     {
         err_print_stack_trace(&lexer.err);
         err_print_stack_trace(&parser.err);
         err_push(&self->err, lexer.line, "invalid module");
+        status = 1;
         goto free_parser;
     }
 
     if (!ast)
     {
+        status = 1;
         goto free_parser;
     }
 
     compiler_t compiler;
     compiler_init(&compiler, self);
-
     compiler_compile(&compiler, ast, &self->prog);
     
+    if (!err_is_ok(&compiler.err))
+    {
+        err_print_stack_trace(&compiler.err);
+        status = 1;
+        goto free_compiler;
+    }
+
+free_compiler:
     compiler_free(&compiler);
     node_free(ast);
     free(ast);
@@ -71,7 +84,7 @@ free_parser:
     parser_free(&parser);
     lexer_free(&lexer);
 
-    return 0;
+    return status;
 }
 
 int module_load_source(module_t* self, char const* path)

lib/module.h

@@ -5,12 +5,14 @@
 #include "prog.h"
 #include "err.h"
 #include "ccm.h"
+#include "sym.h"
 
 typedef struct {
     err_t err;
     char* source;
     prog_t prog;
     ccm_t ccm;
+    sym_t sym;
 } module_t;
 
 void module_init(module_t* self);

lib/node.h

@@ -13,7 +13,10 @@ G(NODE_ASSERT_EQ), G(NODE_ASSERT_NE), G(NODE_BOOL), \
 G(NODE_AND), G(NODE_OR), G(NODE_NOT), G(NODE_IN), \
 G(NODE_OSQUARE), G(NODE_CSQUARE), G(NODE_INDEX), \
 G(NODE_STR), G(NODE_LT), G(NODE_LE), G(NODE_GT), \
-G(NODE_GE), G(NODE_EQ), G(NODE_NE), G(NODE_ARRAY)
+G(NODE_GE), G(NODE_EQ), G(NODE_NE), G(NODE_ARRAY), \
+G(NODE_VAR), G(NODE_IDENT), G(NODE_ASSIGN), \
+G(NODE_VARDECL), G(NODE_CONST), G(NODE_CONSTDECL), \
+G(NODE_BEGIN), G(NODE_BLOCK), G(NODE_END)
 
 CCM_ENUM_H(NodeKind, NODE_KIND);
 

lib/parser.c

@@ -26,7 +26,21 @@ node_t* parser_try_new_parse(parser_t* self)
 
     if (self->lexer->cursor < (ssize_t)strlen(self->lexer->source))
     {
-        err_push(&self->err, res ? res->line : 0, "unexpected end");
+        str_t s;
+        str_init(&s);
+
+        while (self->lexer->cursor
+            < (ssize_t)strlen(self->lexer->source)
+            && !isspace(self->lexer->source[self->lexer->cursor]))
+        {
+            str_push(&s, self->lexer->source[self->lexer->cursor]);
+            self->lexer->cursor++;
+        }
+
+        err_push(&self->err, res ? res->line : 0,
+                 "unexpected end after '%s'", s.value);
+        str_free(&s);
+
     }
 
     return res;
@@ -121,15 +135,155 @@ node_t* parser_try_new_expr(parser_t* self)
 {
     assert(self);
 
+    if (lexer_peek_kind(self->lexer, NODE_VAR, 0)
+     || lexer_peek_kind(self->lexer, NODE_CONST, 0))
+    {
+        return CCM_TRY(parser_try_new_decl);
+    }
+
     if (lexer_peek_kind(self->lexer, NODE_ASSERT_EQ, 0)
         || lexer_peek_kind(self->lexer, NODE_ASSERT_NE, 0))
     {
         return CCM_TRY(parser_try_new_assert);
     }
 
+    if (lexer_peek_kind(self->lexer, NODE_BEGIN, 0))
+    {
+        return CCM_TRY(parser_try_new_begin);
+    }
+
+    node_t* assign = CCM_TRY(parser_try_new_assign);
+    if (assign) { return assign; }
+
     return CCM_TRY(parser_try_new_or);
 }
 
+node_t* parser_try_new_begin(parser_t* self)
+{
+    assert(self);
+
+    if (!lexer_peek_kind(self->lexer, NODE_BEGIN, 0))
+    {
+        return NULL;
+    }
+
+    lexer_consume_next(self->lexer, NODE_BEGIN);
+
+    node_t* node = malloc(sizeof(node_t));
+    node_init(node, NODE_BEGIN, "", self->lexer->line);
+    
+    node_t* block = CCM_TRY(parser_try_new_block);
+    node_push_new_child(node, block);
+
+    if (!block || !lexer_peek_kind(self->lexer, NODE_END, 0))
+    {
+        node_free(node); free(node);
+        return NULL;
+    }
+
+    lexer_consume_next(self->lexer, NODE_END);
+
+    return node;
+}
+
+node_t* parser_try_new_block(parser_t* self)
+{
+    assert(self);
+    node_t* node = malloc(sizeof(node_t));
+    node_init(node, NODE_BLOCK, "", self->lexer->line);
+
+    while (1) 
+    {
+        node_t* expr = CCM_TRY(parser_try_new_expr);
+        if (!expr) { break; }
+
+        node_push_new_child(node, expr);
+    }
+    
+    return node;
+}
+
+node_t* parser_try_new_assign(parser_t* self)
+{
+    assert(self);
+    node_t* target = CCM_TRY(parser_try_new_index);
+
+    if (!target && lexer_peek_kind(self->lexer, NODE_IDENT, 0)) {
+        target = lexer_try_new_next(self->lexer);
+    }
+
+    if (target == NULL) {
+        return NULL;
+    }
+
+    if (!lexer_peek_kind(self->lexer, NODE_ASSIGN, 0))
+    {
+        node_free(target); free(target);
+        return NULL;
+    }
+
+    lexer_consume_next(self->lexer, NODE_ASSIGN);
+    node_t* expr = CCM_TRY(parser_try_new_expr);
+
+    if (!expr)
+    {
+        node_free(target); free(target);
+        return NULL;
+    }
+
+    node_t* node = malloc(sizeof(node_t));
+    node_init(node, NODE_ASSIGN, "", self->lexer->line);
+    node_push_new_child(node, target);
+    node_push_new_child(node, expr);
+
+    return node;
+}
+
+node_t* parser_try_new_decl(parser_t* self)
+{
+    assert(self);
+
+    int is_const = 0;
+
+    if (lexer_peek_kind(self->lexer, NODE_VAR, 0)) {
+        lexer_consume_next(self->lexer, NODE_VAR);
+    } else if (lexer_peek_kind(self->lexer, NODE_CONST, 0)) {
+        lexer_consume_next(self->lexer, NODE_CONST);
+        is_const = 1;
+    } else {
+        return NULL;
+    }
+
+    if (!lexer_peek_kind(self->lexer, NODE_IDENT, 0))
+    {
+        return NULL;
+    }
+
+    node_t* ident = lexer_try_new_next(self->lexer);
+
+    if (!lexer_consume_next(self->lexer, NODE_ASSIGN))
+    {
+        node_free(ident); free(ident);
+        return NULL;
+    }
+
+    node_t* expr = CCM_TRY(parser_try_new_expr);
+    if (!expr)
+    {
+        node_free(ident); free(ident);
+        return NULL;
+    }
+
+    node_t* node = malloc(sizeof(node_t));
+    node_init(node, is_const ? NODE_CONSTDECL : NODE_VARDECL, 
+              "", self->lexer->line);
+
+    node_push_new_child(node, ident);
+    node_push_new_child(node, expr);
+
+    return node;
+}
+
 node_t* parser_try_new_assert(parser_t* self)
 {
     assert(self);
@@ -478,15 +632,12 @@ node_t* parser_try_new_literal(parser_t* self)
 {
     assert(self);
 
+    node_t* index = CCM_TRY(parser_try_new_index);
+    if (index) { return index; }
+
     if (lexer_peek_kind(self->lexer, NODE_OSQUARE, 0))
     {
         node_t* array = CCM_TRY(parser_try_new_array);
-
-        if (lexer_peek_kind(self->lexer, NODE_OSQUARE, 0))
-        {
-            return CCM_TRY_LL1(parser_try_new_index, array);
-        }
-
         return array;
     }
 
@@ -496,11 +647,6 @@ node_t* parser_try_new_literal(parser_t* self)
 
         if (tuple)
         {
-            if (lexer_peek_kind(self->lexer, NODE_OSQUARE, 0))
-            {
-                return CCM_TRY_LL1(parser_try_new_index, tuple);
-            }
-
             return tuple;
         }
 
@@ -526,13 +672,6 @@ node_t* parser_try_new_literal(parser_t* self)
         return expr;
     }
 
-    if (lexer_peek_kind(self->lexer, NODE_STR, 0)
-        && lexer_peek_kind(self->lexer, NODE_OSQUARE, 1))
-    {
-        node_t* target = CCM_TRY(parser_try_new_builtin);
-        return CCM_TRY_LL1(parser_try_new_index, target);
-    }
-
     return CCM_TRY(parser_try_new_builtin);
 }
 
@@ -543,6 +682,12 @@ node_t* parser_try_new_array(parser_t* self)
     node_t* node = malloc(sizeof(node_t));
     node_init(node, NODE_ARRAY, "", self->lexer->line);
     
+    if (!lexer_peek_kind(self->lexer, NODE_OSQUARE, 0))
+    {
+        node_free(node); free(node);
+        return NULL;
+    }
+
     lexer_consume_next(self->lexer, NODE_OSQUARE);
 
     int first = 1;
@@ -567,15 +712,50 @@ node_t* parser_try_new_array(parser_t* self)
         first = 0;
     }
 
+    if (!lexer_peek_kind(self->lexer, NODE_CSQUARE, 0))
+    {
+        node_free(node); free(node);
+        return NULL;
+    }
+
     lexer_consume_next(self->lexer, NODE_CSQUARE);
 
     return node;
 }
 
-node_t* parser_try_new_index(parser_t* self, node_t* target)
+node_t* parser_try_new_index(parser_t* self)
 {
     assert(self);
 
+    node_t* target = NULL;
+    
+    if (lexer_peek_kind(self->lexer, NODE_STR, 0)
+         || lexer_peek_kind(self->lexer, NODE_IDENT, 0))
+    {
+        target = lexer_try_new_next(self->lexer);
+    }
+
+    if (!target)
+    {
+        target = CCM_TRY(parser_try_new_tuple);
+    }
+
+    if (!target)
+    {
+        target = CCM_TRY(parser_try_new_array);
+    }
+
+    if (target == NULL)
+    {
+        return NULL;
+    }
+
+    if (!lexer_peek_kind(self->lexer, NODE_OSQUARE, 0))
+    {
+        node_free(target); free(target);
+        return NULL;
+    }
+
     lexer_consume_next(self->lexer, NODE_OSQUARE);
 
     node_t* node = malloc(sizeof(node_t));
@@ -589,6 +769,7 @@ node_t* parser_try_new_index(parser_t* self, node_t* target)
         if (!element)
         {
             node_free(node); free(node);
+            node_free(target); free(target);
             return NULL;
         }
 
@@ -600,6 +781,13 @@ node_t* parser_try_new_index(parser_t* self, node_t* target)
         }
     }
 
+    if (!lexer_peek_kind(self->lexer, NODE_CSQUARE, 0))
+    {
+        node_free(node); free(node);
+        node_free(target); free(target);
+        return NULL;
+    }
+
     lexer_consume_next(self->lexer, NODE_CSQUARE);
 
     return node;
@@ -611,13 +799,15 @@ node_t* parser_try_new_tuple(parser_t* self)
     node_t* node = malloc(sizeof(node_t));
     node_init(node, NODE_TUPLE, "", self->lexer->line);
 
-    if (!lexer_consume_next(self->lexer, NODE_OPAR))
+    if (!lexer_peek_kind(self->lexer, NODE_OPAR, 0))
     {
         node_free(node);
         free(node);
         return NULL;
     }
 
+    lexer_consume_next(self->lexer, NODE_OPAR);
+
     node_t* lhs = CCM_TRY(parser_try_new_expr);
 
     if (!lhs)
@@ -648,6 +838,13 @@ node_t* parser_try_new_tuple(parser_t* self)
         contains_more_than_one_expr = 1;
     }
 
+    if (!lexer_peek_kind(self->lexer, NODE_CPAR, 0))
+    {
+        node_free(node);
+        free(node);
+        return NULL;
+    }
+
     lexer_consume_next(self->lexer, NODE_CPAR);
 
     if (!contains_more_than_one_expr)
@@ -671,6 +868,7 @@ node_t* parser_try_new_builtin(parser_t* self)
             node->kind == NODE_NUM
             || node->kind == NODE_BOOL
             || node->kind == NODE_STR
+            || node->kind == NODE_IDENT
         )
     )
     {

lib/parser.h

@@ -25,6 +25,10 @@ int parser_ensure(parser_t* self, node_t* node, NodeKind kind);
 
 node_t* parser_try_new_module(parser_t* self);
 node_t* parser_try_new_expr(parser_t* self);
+node_t* parser_try_new_begin(parser_t* self);
+node_t* parser_try_new_block(parser_t* self);
+node_t* parser_try_new_assign(parser_t* self);
+node_t* parser_try_new_decl(parser_t* self);
 node_t* parser_try_new_assert(parser_t* self);
 node_t* parser_try_new_or(parser_t* self);
 node_t* parser_try_new_and(parser_t* self);
@@ -38,7 +42,7 @@ node_t* parser_try_new_pow(parser_t* self);
 node_t* parser_try_new_in(parser_t* self);
 node_t* parser_try_new_literal(parser_t* self);
 node_t* parser_try_new_array(parser_t* self);
-node_t* parser_try_new_index(parser_t* self, node_t* target);
+node_t* parser_try_new_index(parser_t* self);
 node_t* parser_try_new_tuple(parser_t* self);
 node_t* parser_try_new_builtin(parser_t* self);
 

lib/sym.c

@@ -0,0 +1,157 @@
+#include "sym.h"
+
+void sym_init(sym_t* self)
+{
+    assert(self);
+    self->env = NULL;
+}
+
+void sym_free(sym_t* self)
+{
+    assert(self);
+
+    if (self->env)
+    {
+        sym_free_env(self, self->env);
+        free(self->env);
+    }
+
+}
+
+void sym_free_env(sym_t* self, env_t* env)
+{
+    assert(self);
+    assert(env);
+
+    if (env->parent)
+    {
+        sym_free_env(self, env->parent);
+        free(env->parent);
+    }
+
+    for (size_t i=0; i<env->entries.size; i++)
+    {
+        sym_entry_t* entry = env->entries.data[i];
+        free(entry->name);
+        free(entry);
+    }
+
+    vec_free(&env->entries);
+}
+
+void sym_open_scope(sym_t* self)
+{
+    assert(self);
+    env_t* env = malloc(sizeof(env_t));
+    env->parent = NULL;
+    vec_init(&env->entries);
+
+    if (self->env == NULL) {
+        self->env = env;
+    } else {
+        env->parent = self->env;
+        self->env = env;
+    }
+}
+
+void sym_close_scope(sym_t* self)
+{
+    assert(self);
+    assert(self->env);
+
+    for (size_t i=0; i<self->env->entries.size; i++)
+    {
+        sym_entry_t* entry = self->env->entries.data[i];
+        free(entry->name);
+        free(entry);
+    }
+
+    vec_free(&self->env->entries);
+    env_t* parent = self->env->parent;
+    free(self->env);
+    self->env = parent;
+}
+
+
+int sym_declare(sym_t* self,
+                char const* name,
+                int addr,
+                int is_const)
+{
+    assert(self);
+    assert(self->env);
+    assert(name);
+
+    if (sym_try_get_env_value(self,self->env, name) != NULL)
+    {
+        return 0;
+    }
+
+    sym_entry_t* entry = malloc(sizeof(sym_entry_t));
+    entry->name = strdup(name);
+    entry->local_addr = addr;
+    entry->is_const = is_const;
+    vec_push(&self->env->entries, entry);
+    return 1;
+}
+
+int sym_try_assign(sym_t* self,
+                   char const* name,
+                   int addr)
+{
+    assert(self);
+    assert(name);
+    sym_entry_t* entry = sym_try_get_value(self, name);
+
+    if (!entry) { return 0; }
+
+    entry->local_addr = addr;
+
+    return 1;
+}
+
+sym_entry_t* sym_try_get_value(sym_t* self, char const* name)
+{
+    assert(self);
+    assert(name);
+
+    env_t* env = self->env;
+
+    while (env)
+    {
+        sym_entry_t* entry = sym_try_get_env_value(
+            self,
+            env,
+            name
+        );
+
+        if (entry)
+        {
+            return entry;
+        }
+
+        env = env->parent;
+    }
+
+    return NULL;
+}
+
+sym_entry_t* sym_try_get_env_value(sym_t* self,
+                                   env_t* env,
+                                   char const* name)
+{
+    assert(self); assert(env); assert(name);
+
+    for (size_t i=0; i<env->entries.size; i++)
+    {
+        sym_entry_t const* entry =
+            ((sym_entry_t*) env->entries.data[i]);
+
+        if (strcmp(entry->name, name) == 0)
+        {
+            return env->entries.data[i];
+        }
+    }
+
+    return NULL;
+}

lib/sym.h

@@ -0,0 +1,44 @@
+#ifndef CCM_SYM_H
+#define CCM_SYM_H
+
+#include "commons.h"
+#include "vec.h"
+#include "value.h"
+
+typedef struct {
+    char* name;
+    int local_addr;
+    int is_const;
+} sym_entry_t;
+
+typedef struct env {
+    vec_t entries;
+    struct env* parent;
+} env_t;
+
+typedef struct {
+    env_t* env;
+} sym_t;
+
+void sym_init(sym_t* self);
+void sym_free(sym_t* self);
+void sym_free_env(sym_t* self, env_t* env);
+
+void sym_open_scope(sym_t* self);
+void sym_close_scope(sym_t* self);
+
+int sym_declare(sym_t* self,
+                char const* name,
+                int addr,
+                int is_const);
+
+int sym_try_assign(sym_t* self,
+                   char const* name,
+                   int addr);
+
+sym_entry_t* sym_try_get_value(sym_t* self, char const* name);
+sym_entry_t* sym_try_get_env_value(sym_t* self,
+                                   env_t* env,
+                                   char const* name);
+
+#endif

tests/block.ccm

@@ -0,0 +1,36 @@
+var a = 12
+
+begin
+    a = 32
+end
+
+assert_eq (32, a)
+
+# SHADOWING
+# =========
+
+var b = 34
+
+begin
+    var b = "bim"
+    assert_eq ("bim", b)
+end
+
+assert_eq(34, b)
+
+# NESTED BLOCKS
+# =============
+var c = "hello"
+
+begin
+    var c = "world"
+    begin
+        var c = "pizza"
+        c = "cat"
+        assert_eq ("cat", c)
+    end
+    assert_eq ("world", c)
+end
+
+assert_eq ("hello", c)
+

tests/var.ccm

@@ -0,0 +1,33 @@
+# DECLARATION
+# ===========
+var a = 32
+assert_eq (32, a)
+
+var b = a + 1
+assert_eq(33, b)
+
+var c = (var d = 3)
+assert_eq(3, c)
+assert_eq(3, d)
+
+var e = [1, 2]
+assert_eq (2, e[-1])
+
+var f = [2, 3]
+var g = 1
+
+assert_eq (3, f[g])
+
+# ASSIGN
+# ======
+var h = 34
+h = 37
+assert_eq (37, h)
+
+var i = [2, 3, 4]
+i[2] = 7
+assert_eq ([2, 3, 7], i)
+
+var j = [[1, 2], [3, 4]]
+j[1, 0] = 99
+assert_eq ([[1, 2], [99, 4]], j)