Add syntax parser and integrate lexical analysis

.gitignore

@@ -1 +1,3 @@
 .priv/
+build/
+programa.bl

CMakeLists.txt

@@ -1,5 +1,5 @@
-
 cmake_minimum_required(VERSION 3.20)
+
 project(BLCeti VERSION 0.1.0 LANGUAGES C)
 
 set(CMAKE_C_STANDARD 17)
@@ -9,6 +9,7 @@ set(CMAKE_C_EXTENSIONS OFF)
 add_executable(BL
     src/main.c
     src/lexer.c
+    src/parser.c
 )
 
 target_include_directories(BL PRIVATE include)

build/CMakeFiles/BL.dir/DependInfo.cmake

@@ -10,6 +10,7 @@ set(CMAKE_DEPENDS_LANGUAGES
 set(CMAKE_DEPENDS_DEPENDENCY_FILES
   "/home/benicio/Escritorio/BL-Ceti/src/lexer.c" "CMakeFiles/BL.dir/src/lexer.c.o" "gcc" "CMakeFiles/BL.dir/src/lexer.c.o.d"
   "/home/benicio/Escritorio/BL-Ceti/src/main.c" "CMakeFiles/BL.dir/src/main.c.o" "gcc" "CMakeFiles/BL.dir/src/main.c.o.d"
+  "/home/benicio/Escritorio/BL-Ceti/src/parser.c" "CMakeFiles/BL.dir/src/parser.c.o" "gcc" "CMakeFiles/BL.dir/src/parser.c.o.d"
   "" "BL" "gcc" "CMakeFiles/BL.dir/link.d"
   )
 

build/CMakeFiles/BL.dir/build.make

@@ -100,20 +100,36 @@ CMakeFiles/BL.dir/src/lexer.c.s: cmake_force
 	@$(CMAKE_COMMAND) -E cmake_echo_color "--switch=$(COLOR)" --green "Compiling C source to assembly CMakeFiles/BL.dir/src/lexer.c.s"
 	/usr/bin/cc $(C_DEFINES) $(C_INCLUDES) $(C_FLAGS) -S /home/benicio/Escritorio/BL-Ceti/src/lexer.c -o CMakeFiles/BL.dir/src/lexer.c.s
 
+CMakeFiles/BL.dir/src/parser.c.o: CMakeFiles/BL.dir/flags.make
+CMakeFiles/BL.dir/src/parser.c.o: /home/benicio/Escritorio/BL-Ceti/src/parser.c
+CMakeFiles/BL.dir/src/parser.c.o: CMakeFiles/BL.dir/compiler_depend.ts
+	@$(CMAKE_COMMAND) -E cmake_echo_color "--switch=$(COLOR)" --green --progress-dir=/home/benicio/Escritorio/BL-Ceti/build/CMakeFiles --progress-num=$(CMAKE_PROGRESS_3) "Building C object CMakeFiles/BL.dir/src/parser.c.o"
+	/usr/bin/cc $(C_DEFINES) $(C_INCLUDES) $(C_FLAGS) -MD -MT CMakeFiles/BL.dir/src/parser.c.o -MF CMakeFiles/BL.dir/src/parser.c.o.d -o CMakeFiles/BL.dir/src/parser.c.o -c /home/benicio/Escritorio/BL-Ceti/src/parser.c
+
+CMakeFiles/BL.dir/src/parser.c.i: cmake_force
+	@$(CMAKE_COMMAND) -E cmake_echo_color "--switch=$(COLOR)" --green "Preprocessing C source to CMakeFiles/BL.dir/src/parser.c.i"
+	/usr/bin/cc $(C_DEFINES) $(C_INCLUDES) $(C_FLAGS) -E /home/benicio/Escritorio/BL-Ceti/src/parser.c > CMakeFiles/BL.dir/src/parser.c.i
+
+CMakeFiles/BL.dir/src/parser.c.s: cmake_force
+	@$(CMAKE_COMMAND) -E cmake_echo_color "--switch=$(COLOR)" --green "Compiling C source to assembly CMakeFiles/BL.dir/src/parser.c.s"
+	/usr/bin/cc $(C_DEFINES) $(C_INCLUDES) $(C_FLAGS) -S /home/benicio/Escritorio/BL-Ceti/src/parser.c -o CMakeFiles/BL.dir/src/parser.c.s
+
 # Object files for target BL
 BL_OBJECTS = \
 "CMakeFiles/BL.dir/src/main.c.o" \
-"CMakeFiles/BL.dir/src/lexer.c.o"
+"CMakeFiles/BL.dir/src/lexer.c.o" \
+"CMakeFiles/BL.dir/src/parser.c.o"
 
 # External object files for target BL
 BL_EXTERNAL_OBJECTS =
 
 BL: CMakeFiles/BL.dir/src/main.c.o
 BL: CMakeFiles/BL.dir/src/lexer.c.o
+BL: CMakeFiles/BL.dir/src/parser.c.o
 BL: CMakeFiles/BL.dir/build.make
 BL: CMakeFiles/BL.dir/compiler_depend.ts
 BL: CMakeFiles/BL.dir/link.txt
-	@$(CMAKE_COMMAND) -E cmake_echo_color "--switch=$(COLOR)" --green --bold --progress-dir=/home/benicio/Escritorio/BL-Ceti/build/CMakeFiles --progress-num=$(CMAKE_PROGRESS_3) "Linking C executable BL"
+	@$(CMAKE_COMMAND) -E cmake_echo_color "--switch=$(COLOR)" --green --bold --progress-dir=/home/benicio/Escritorio/BL-Ceti/build/CMakeFiles --progress-num=$(CMAKE_PROGRESS_4) "Linking C executable BL"
 	$(CMAKE_COMMAND) -E cmake_link_script CMakeFiles/BL.dir/link.txt --verbose=$(VERBOSE)
 
 # Rule to build all files generated by this target.

build/CMakeFiles/BL.dir/cmake_clean.cmake

@@ -6,6 +6,8 @@ file(REMOVE_RECURSE
   "CMakeFiles/BL.dir/src/lexer.c.o.d"
   "CMakeFiles/BL.dir/src/main.c.o"
   "CMakeFiles/BL.dir/src/main.c.o.d"
+  "CMakeFiles/BL.dir/src/parser.c.o"
+  "CMakeFiles/BL.dir/src/parser.c.o.d"
 )
 
 # Per-language clean rules from dependency scanning.

build/CMakeFiles/BL.dir/link.d

@@ -4,6 +4,7 @@ BL: \
   /usr/lib/gcc/x86_64-pc-linux-gnu/16/crtbeginS.o \
   CMakeFiles/BL.dir/src/main.c.o \
   CMakeFiles/BL.dir/src/lexer.c.o \
+  CMakeFiles/BL.dir/src/parser.c.o \
   /usr/lib/gcc/x86_64-pc-linux-gnu/16/libgcc.a \
   /usr/lib/gcc/x86_64-pc-linux-gnu/16/libgcc_s_asneeded.so \
   /usr/lib/gcc/x86_64-pc-linux-gnu/16/libgcc_s_asneeded.so \
@@ -46,6 +47,8 @@ CMakeFiles/BL.dir/src/main.c.o:
 
 CMakeFiles/BL.dir/src/lexer.c.o:
 
+CMakeFiles/BL.dir/src/parser.c.o:
+
 /usr/lib/gcc/x86_64-pc-linux-gnu/16/libgcc.a:
 
 /usr/lib/gcc/x86_64-pc-linux-gnu/16/libgcc_s_asneeded.so:

build/CMakeFiles/BL.dir/link.txt

@@ -1 +1 @@
-/usr/bin/cc -Wl,--dependency-file=CMakeFiles/BL.dir/link.d CMakeFiles/BL.dir/src/main.c.o CMakeFiles/BL.dir/src/lexer.c.o -o BL
+/usr/bin/cc -Wl,--dependency-file=CMakeFiles/BL.dir/link.d CMakeFiles/BL.dir/src/main.c.o CMakeFiles/BL.dir/src/lexer.c.o CMakeFiles/BL.dir/src/parser.c.o -o BL

build/CMakeFiles/BL.dir/progress.make

@@ -1,4 +1,5 @@
 CMAKE_PROGRESS_1 = 1
 CMAKE_PROGRESS_2 = 2
 CMAKE_PROGRESS_3 = 3
+CMAKE_PROGRESS_4 = 4
 

build/CMakeFiles/BL.dir/src/main.c.o.d

@@ -3,11 +3,13 @@ CMakeFiles/BL.dir/src/main.c.o: \
  /home/benicio/Escritorio/BL-Ceti/include/lexer.h \
  /usr/lib/gcc/x86_64-pc-linux-gnu/16/include/stdbool.h \
  /usr/lib/gcc/x86_64-pc-linux-gnu/16/include/stddef.h \
- /usr/include/stdio.h /usr/include/bits/libc-header-start.h \
- /usr/include/features.h /usr/include/features-time64.h \
- /usr/include/bits/wordsize.h /usr/include/bits/timesize.h \
- /usr/include/sys/cdefs.h /usr/include/bits/long-double.h \
- /usr/include/gnu/stubs.h /usr/include/gnu/stubs-64.h \
+ /home/benicio/Escritorio/BL-Ceti/include/parser.h \
+ /home/benicio/Escritorio/BL-Ceti/include/lexer.h /usr/include/stdio.h \
+ /usr/include/bits/libc-header-start.h /usr/include/features.h \
+ /usr/include/features-time64.h /usr/include/bits/wordsize.h \
+ /usr/include/bits/timesize.h /usr/include/sys/cdefs.h \
+ /usr/include/bits/long-double.h /usr/include/gnu/stubs.h \
+ /usr/include/gnu/stubs-64.h \
  /usr/lib/gcc/x86_64-pc-linux-gnu/16/include/stdarg.h \
  /usr/include/bits/types.h /usr/include/bits/typesizes.h \
  /usr/include/bits/time64.h /usr/include/bits/types/__fpos_t.h \

build/CMakeFiles/Makefile2

@@ -85,12 +85,12 @@ clean: CMakeFiles/BL.dir/clean
 CMakeFiles/BL.dir/all:
 	$(MAKE) $(MAKESILENT) -f CMakeFiles/BL.dir/build.make CMakeFiles/BL.dir/depend
 	$(MAKE) $(MAKESILENT) -f CMakeFiles/BL.dir/build.make CMakeFiles/BL.dir/build
-	@$(CMAKE_COMMAND) -E cmake_echo_color "--switch=$(COLOR)" --progress-dir=/home/benicio/Escritorio/BL-Ceti/build/CMakeFiles --progress-num=1,2,3 "Built target BL"
+	@$(CMAKE_COMMAND) -E cmake_echo_color "--switch=$(COLOR)" --progress-dir=/home/benicio/Escritorio/BL-Ceti/build/CMakeFiles --progress-num=1,2,3,4 "Built target BL"
 .PHONY : CMakeFiles/BL.dir/all
 
 # Build rule for subdir invocation for target.
 CMakeFiles/BL.dir/rule: cmake_check_build_system
-	$(CMAKE_COMMAND) -E cmake_progress_start /home/benicio/Escritorio/BL-Ceti/build/CMakeFiles 3
+	$(CMAKE_COMMAND) -E cmake_progress_start /home/benicio/Escritorio/BL-Ceti/build/CMakeFiles 4
 	$(MAKE) $(MAKESILENT) -f CMakeFiles/Makefile2 CMakeFiles/BL.dir/all
 	$(CMAKE_COMMAND) -E cmake_progress_start /home/benicio/Escritorio/BL-Ceti/build/CMakeFiles 0
 .PHONY : CMakeFiles/BL.dir/rule
@@ -102,7 +102,7 @@ BL: CMakeFiles/BL.dir/rule
 # codegen rule for target.
 CMakeFiles/BL.dir/codegen:
 	$(MAKE) $(MAKESILENT) -f CMakeFiles/BL.dir/build.make CMakeFiles/BL.dir/codegen
-	@$(CMAKE_COMMAND) -E cmake_echo_color "--switch=$(COLOR)" --progress-dir=/home/benicio/Escritorio/BL-Ceti/build/CMakeFiles --progress-num=1,2,3 "Finished codegen for target BL"
+	@$(CMAKE_COMMAND) -E cmake_echo_color "--switch=$(COLOR)" --progress-dir=/home/benicio/Escritorio/BL-Ceti/build/CMakeFiles --progress-num=1,2,3,4 "Finished codegen for target BL"
 .PHONY : CMakeFiles/BL.dir/codegen
 
 # clean rule for target.

build/CMakeFiles/progress.marks

@@ -1 +1 @@
-3
+4

build/Makefile

@@ -222,6 +222,30 @@ src/main.c.s:
 	$(MAKE) $(MAKESILENT) -f CMakeFiles/BL.dir/build.make CMakeFiles/BL.dir/src/main.c.s
 .PHONY : src/main.c.s
 
+src/parser.o: src/parser.c.o
+.PHONY : src/parser.o
+
+# target to build an object file
+src/parser.c.o:
+	$(MAKE) $(MAKESILENT) -f CMakeFiles/BL.dir/build.make CMakeFiles/BL.dir/src/parser.c.o
+.PHONY : src/parser.c.o
+
+src/parser.i: src/parser.c.i
+.PHONY : src/parser.i
+
+# target to preprocess a source file
+src/parser.c.i:
+	$(MAKE) $(MAKESILENT) -f CMakeFiles/BL.dir/build.make CMakeFiles/BL.dir/src/parser.c.i
+.PHONY : src/parser.c.i
+
+src/parser.s: src/parser.c.s
+.PHONY : src/parser.s
+
+# target to generate assembly for a file
+src/parser.c.s:
+	$(MAKE) $(MAKESILENT) -f CMakeFiles/BL.dir/build.make CMakeFiles/BL.dir/src/parser.c.s
+.PHONY : src/parser.c.s
+
 # Help Target
 help:
 	@echo "The following are some of the valid targets for this Makefile:"
@@ -241,6 +265,9 @@ help:
 	@echo "... src/main.o"
 	@echo "... src/main.i"
 	@echo "... src/main.s"
+	@echo "... src/parser.o"
+	@echo "... src/parser.i"
+	@echo "... src/parser.s"
 .PHONY : help
 
 

include/parser.h

@@ -0,0 +1,18 @@
+#ifndef BL_CETI_PARSER_H
+#define BL_CETI_PARSER_H
+
+#include "lexer.h"
+
+#include <stdbool.h>
+#include <stddef.h>
+
+typedef struct {
+    char code[6];
+    char message[160];
+    size_t line;
+    size_t column;
+} BlParseError;
+
+bool bl_parse(const BlToken *tokens, size_t count, BlParseError *error);
+
+#endif

programa.bl

@@ -1,4 +1,7 @@
+cat > /tmp/bl-error.bl <<'EOF'
 fn main() {
-    let mensaje: String = "Hola desde BL-Ceti";
-    print(mensaje);
+    let numero: Int = ;
 }
+EOF
+
+./build/BL .C /tmp/bl-error.bl

src/main.c

@@ -1,5 +1,5 @@
-
 #include "lexer.h"
+#include "parser.h"
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -16,6 +16,7 @@ static char *read_file(const char *path, size_t *length)
 
     if (fseek(file, 0, SEEK_END) != 0) {
         fclose(file);
+        fprintf(stderr, "BL: no se pudo leer el archivo.\n");
         return NULL;
     }
 
@@ -23,6 +24,7 @@ static char *read_file(const char *path, size_t *length)
 
     if (size < 0 || fseek(file, 0, SEEK_SET) != 0) {
         fclose(file);
+        fprintf(stderr, "BL: no se pudo determinar el tamaño del archivo.\n");
         return NULL;
     }
 
@@ -46,6 +48,7 @@ static char *read_file(const char *path, size_t *length)
     buffer[read_count] = '\0';
     *length = read_count;
     fclose(file);
+
     return buffer;
 }
 
@@ -54,29 +57,48 @@ static int analyze_file(const char *path)
     size_t length = 0;
     char *source = read_file(path, &length);
 
-    if (source == NULL) return 1;
+    if (source == NULL) {
+        return 1;
+    }
 
-    BlLexResult result = {0};
-    bool success = bl_lex(source, length, &result);
+    BlLexResult lex_result = {0};
 
-    if (!success) {
+    if (!bl_lex(source, length, &lex_result)) {
         fprintf(stderr, "%s:%zu:%zu: error %s: %s\n",
                 path,
-                result.error.line,
-                result.error.column,
-                result.error.code,
-                result.error.message);
-        bl_lex_result_destroy(&result);
+                lex_result.error.line,
+                lex_result.error.column,
+                lex_result.error.code,
+                lex_result.error.message);
+
+        bl_lex_result_destroy(&lex_result);
         free(source);
         return 1;
     }
 
-    printf("BL-Ceti: analisis lexico correcto: %s\n", path);
-    printf("Tokens reconocidos: %zu\n",
-           result.count > 0 ? result.count - 1 : 0);
+    BlParseError parse_error = {0};
 
-    bl_lex_result_destroy(&result);
+    if (!bl_parse(lex_result.tokens, lex_result.count, &parse_error)) {
+        fprintf(stderr, "%s:%zu:%zu: error %s: %s\n",
+                path,
+                parse_error.line,
+                parse_error.column,
+                parse_error.code,
+                parse_error.message);
+
+        bl_lex_result_destroy(&lex_result);
         free(source);
+        return 1;
+    }
+
+    printf("BL-Ceti 0.1.0: analisis correcto: %s\n", path);
+    printf("Tokens reconocidos: %zu\n",
+           lex_result.count > 0 ? lex_result.count - 1 : 0);
+    printf("Sintaxis: correcta\n");
+
+    bl_lex_result_destroy(&lex_result);
+    free(source);
+
     return 0;
 }
 

src/parser.c

@@ -0,0 +1,639 @@
+#include "parser.h"
+
+#include <stdio.h>
+#include <string.h>
+
+typedef struct {
+    const BlToken *tokens;
+    size_t count;
+    size_t position;
+    BlParseError *error;
+    bool failed;
+} Parser;
+
+typedef struct {
+    bool identifier;
+    bool call;
+} ExprInfo;
+
+static const BlToken *current(Parser *parser)
+{
+    if (parser->position >= parser->count) {
+        return &parser->tokens[parser->count - 1];
+    }
+
+    return &parser->tokens[parser->position];
+}
+
+static bool check(Parser *parser, BlTokenType type)
+{
+    return current(parser)->type == type;
+}
+
+static const BlToken *advance(Parser *parser)
+{
+    const BlToken *token = current(parser);
+
+    if (token->type != BL_EOF) {
+        parser->position++;
+    }
+
+    return token;
+}
+
+static bool fail_at(Parser *parser, const BlToken *token,
+                    const char *code, const char *message)
+{
+    if (!parser->failed) {
+        parser->failed = true;
+
+        snprintf(parser->error->code, sizeof parser->error->code,
+                 "%s", code);
+        snprintf(parser->error->message, sizeof parser->error->message,
+                 "%s", message);
+
+        parser->error->line = token->line;
+        parser->error->column = token->column;
+    }
+
+    return false;
+}
+
+static bool expect(Parser *parser, BlTokenType type,
+                   const char *message)
+{
+    if (check(parser, type)) {
+        advance(parser);
+        return true;
+    }
+
+    return fail_at(parser, current(parser), "E1001", message);
+}
+
+static bool parse_expression(Parser *parser, ExprInfo *info);
+static bool parse_statement(Parser *parser);
+static bool parse_block(Parser *parser);
+
+static bool parse_type(Parser *parser, bool allow_void)
+{
+    BlTokenType type = current(parser)->type;
+
+    if (type == BL_INT_TYPE ||
+        type == BL_FLOAT_TYPE ||
+        type == BL_BOOL_TYPE ||
+        type == BL_STRING_TYPE) {
+        advance(parser);
+    return true;
+        }
+
+        if (allow_void && type == BL_VOID_TYPE) {
+            advance(parser);
+            return true;
+        }
+
+        return fail_at(parser, current(parser), "E1001",
+                       "Se esperaba un tipo valido.");
+}
+
+static bool parse_primary(Parser *parser, ExprInfo *info)
+{
+    const BlToken *token = current(parser);
+
+    info->identifier = false;
+    info->call = false;
+
+    switch (token->type) {
+        case BL_INTEGER:
+        case BL_FLOAT:
+        case BL_STRING:
+        case BL_TRUE:
+        case BL_FALSE:
+            advance(parser);
+            return true;
+
+        case BL_IDENTIFIER:
+            advance(parser);
+
+            if (check(parser, BL_LPAREN)) {
+                advance(parser);
+
+                if (!check(parser, BL_RPAREN)) {
+                    ExprInfo argument;
+
+                    if (!parse_expression(parser, &argument)) {
+                        return false;
+                    }
+
+                    while (check(parser, BL_COMMA)) {
+                        advance(parser);
+
+                        if (check(parser, BL_RPAREN)) {
+                            break;
+                        }
+
+                        if (!parse_expression(parser, &argument)) {
+                            return false;
+                        }
+                    }
+                }
+
+                if (!expect(parser, BL_RPAREN,
+                    "Se esperaba ')' al cerrar la llamada.")) {
+                    return false;
+                    }
+
+                    info->call = true;
+                return true;
+            }
+
+            info->identifier = true;
+            return true;
+
+        case BL_LPAREN: {
+            advance(parser);
+
+            ExprInfo inner;
+
+            if (!parse_expression(parser, &inner)) {
+                return false;
+            }
+
+            if (!expect(parser, BL_RPAREN,
+                "Se esperaba ')' en la expresion.")) {
+                return false;
+                }
+
+                return true;
+        }
+
+        default:
+            return fail_at(parser, token, "E1001",
+                           "Se esperaba una expresion.");
+    }
+}
+
+static bool parse_unary(Parser *parser, ExprInfo *info)
+{
+    if (check(parser, BL_MINUS) || check(parser, BL_NOT)) {
+        advance(parser);
+
+        if (!parse_unary(parser, info)) {
+            return false;
+        }
+
+        info->identifier = false;
+        info->call = false;
+        return true;
+    }
+
+    return parse_primary(parser, info);
+}
+
+static bool parse_cast(Parser *parser, ExprInfo *info)
+{
+    if (!parse_unary(parser, info)) {
+        return false;
+    }
+
+    while (check(parser, BL_AS)) {
+        advance(parser);
+
+        if (!parse_type(parser, false)) {
+            return false;
+        }
+
+        info->identifier = false;
+        info->call = false;
+    }
+
+    return true;
+}
+
+static bool parse_multiplication(Parser *parser, ExprInfo *info)
+{
+    if (!parse_cast(parser, info)) {
+        return false;
+    }
+
+    while (check(parser, BL_STAR) ||
+        check(parser, BL_SLASH) ||
+        check(parser, BL_PERCENT)) {
+        advance(parser);
+
+    ExprInfo right;
+
+    if (!parse_cast(parser, &right)) {
+        return false;
+    }
+
+    info->identifier = false;
+    info->call = false;
+        }
+
+        return true;
+}
+
+static bool parse_addition(Parser *parser, ExprInfo *info)
+{
+    if (!parse_multiplication(parser, info)) {
+        return false;
+    }
+
+    while (check(parser, BL_PLUS) || check(parser, BL_MINUS)) {
+        advance(parser);
+
+        ExprInfo right;
+
+        if (!parse_multiplication(parser, &right)) {
+            return false;
+        }
+
+        info->identifier = false;
+        info->call = false;
+    }
+
+    return true;
+}
+
+static bool is_relational(BlTokenType type)
+{
+    return type == BL_LESS ||
+    type == BL_LESS_EQUAL ||
+    type == BL_GREATER ||
+    type == BL_GREATER_EQUAL;
+}
+
+static bool parse_relation(Parser *parser, ExprInfo *info)
+{
+    if (!parse_addition(parser, info)) {
+        return false;
+    }
+
+    if (is_relational(current(parser)->type)) {
+        advance(parser);
+
+        ExprInfo right;
+
+        if (!parse_addition(parser, &right)) {
+            return false;
+        }
+
+        info->identifier = false;
+        info->call = false;
+
+        if (is_relational(current(parser)->type)) {
+            return fail_at(parser, current(parser), "E1005",
+                           "Las comparaciones relacionales no se pueden encadenar.");
+        }
+    }
+
+    return true;
+}
+
+static bool parse_equality(Parser *parser, ExprInfo *info)
+{
+    if (!parse_relation(parser, info)) {
+        return false;
+    }
+
+    if (check(parser, BL_EQUAL) || check(parser, BL_NOT_EQUAL)) {
+        advance(parser);
+
+        ExprInfo right;
+
+        if (!parse_relation(parser, &right)) {
+            return false;
+        }
+
+        info->identifier = false;
+        info->call = false;
+
+        if (check(parser, BL_EQUAL) || check(parser, BL_NOT_EQUAL)) {
+            return fail_at(parser, current(parser), "E1005",
+                           "Las comparaciones de igualdad no se pueden encadenar.");
+        }
+    }
+
+    return true;
+}
+
+static bool parse_and(Parser *parser, ExprInfo *info)
+{
+    if (!parse_equality(parser, info)) {
+        return false;
+    }
+
+    while (check(parser, BL_AND)) {
+        advance(parser);
+
+        ExprInfo right;
+
+        if (!parse_equality(parser, &right)) {
+            return false;
+        }
+
+        info->identifier = false;
+        info->call = false;
+    }
+
+    return true;
+}
+
+static bool parse_expression(Parser *parser, ExprInfo *info)
+{
+    if (!parse_and(parser, info)) {
+        return false;
+    }
+
+    while (check(parser, BL_OR)) {
+        advance(parser);
+
+        ExprInfo right;
+
+        if (!parse_and(parser, &right)) {
+            return false;
+        }
+
+        info->identifier = false;
+        info->call = false;
+    }
+
+    return true;
+}
+
+static bool is_assignment_operator(BlTokenType type)
+{
+    return type == BL_ASSIGN ||
+    type == BL_PLUS_ASSIGN ||
+    type == BL_MINUS_ASSIGN ||
+    type == BL_STAR_ASSIGN ||
+    type == BL_SLASH_ASSIGN ||
+    type == BL_PERCENT_ASSIGN;
+}
+
+static bool parse_variable(Parser *parser)
+{
+    advance(parser); /* let o var */
+
+    if (!expect(parser, BL_IDENTIFIER,
+        "Se esperaba un nombre de variable.")) {
+        return false;
+        }
+
+        if (check(parser, BL_COLON)) {
+            advance(parser);
+
+            if (!parse_type(parser, false)) {
+                return false;
+            }
+        }
+
+        if (!expect(parser, BL_ASSIGN,
+            "Se esperaba '=' para inicializar la variable.")) {
+            return false;
+            }
+
+            ExprInfo value;
+
+        if (!parse_expression(parser, &value)) {
+            return false;
+        }
+
+        return expect(parser, BL_SEMICOLON,
+                      "Se esperaba ';' al final de la declaracion.");
+}
+
+static bool parse_if(Parser *parser)
+{
+    advance(parser); /* if */
+
+    ExprInfo condition;
+
+    if (!parse_expression(parser, &condition)) {
+        return false;
+    }
+
+    if (!parse_block(parser)) {
+        return false;
+    }
+
+    if (check(parser, BL_ELSE)) {
+        advance(parser);
+
+        if (check(parser, BL_IF)) {
+            return parse_if(parser);
+        }
+
+        return parse_block(parser);
+    }
+
+    return true;
+}
+
+static bool parse_while(Parser *parser)
+{
+    advance(parser); /* while */
+
+    ExprInfo condition;
+
+    if (!parse_expression(parser, &condition)) {
+        return false;
+    }
+
+    return parse_block(parser);
+}
+
+static bool parse_return(Parser *parser)
+{
+    advance(parser); /* return */
+
+    if (!check(parser, BL_SEMICOLON)) {
+        ExprInfo value;
+
+        if (!parse_expression(parser, &value)) {
+            return false;
+        }
+    }
+
+    return expect(parser, BL_SEMICOLON,
+                  "Se esperaba ';' despues de return.");
+}
+
+static bool parse_simple_statement(Parser *parser)
+{
+    ExprInfo expression;
+
+    if (!parse_expression(parser, &expression)) {
+        return false;
+    }
+
+    if (is_assignment_operator(current(parser)->type)) {
+        if (!expression.identifier) {
+            return fail_at(parser, current(parser), "E1006",
+                           "El lado izquierdo de una asignacion debe ser una variable.");
+        }
+
+        advance(parser);
+
+        ExprInfo value;
+
+        if (!parse_expression(parser, &value)) {
+            return false;
+        }
+    } else if (!expression.call) {
+        return fail_at(parser, current(parser), "E1007",
+                       "Una sentencia de expresion debe ser una llamada a funcion.");
+    }
+
+    return expect(parser, BL_SEMICOLON,
+                  "Se esperaba ';' al final de la sentencia.");
+}
+
+static bool parse_statement(Parser *parser)
+{
+    switch (current(parser)->type) {
+        case BL_LET:
+        case BL_VAR:
+            return parse_variable(parser);
+
+        case BL_IF:
+            return parse_if(parser);
+
+        case BL_WHILE:
+            return parse_while(parser);
+
+        case BL_BREAK:
+        case BL_CONTINUE:
+            advance(parser);
+            return expect(parser, BL_SEMICOLON,
+                          "Se esperaba ';' despues de la sentencia.");
+
+        case BL_RETURN:
+            return parse_return(parser);
+
+        case BL_LBRACE:
+            return parse_block(parser);
+
+        case BL_IDENTIFIER:
+        case BL_INTEGER:
+        case BL_FLOAT:
+        case BL_STRING:
+        case BL_TRUE:
+        case BL_FALSE:
+        case BL_LPAREN:
+        case BL_MINUS:
+        case BL_NOT:
+            return parse_simple_statement(parser);
+
+        default:
+            return fail_at(parser, current(parser), "E1001",
+                           "Sentencia no valida.");
+    }
+}
+
+static bool parse_block(Parser *parser)
+{
+    if (!expect(parser, BL_LBRACE,
+        "Se esperaba '{' para comenzar el bloque.")) {
+        return false;
+        }
+
+        while (!check(parser, BL_RBRACE) &&
+            !check(parser, BL_EOF) &&
+            !parser->failed) {
+            if (!parse_statement(parser)) {
+                return false;
+            }
+            }
+
+            return expect(parser, BL_RBRACE,
+                          "Se esperaba '}' para cerrar el bloque.");
+}
+
+static bool parse_function(Parser *parser)
+{
+    advance(parser); /* fn */
+
+    if (!expect(parser, BL_IDENTIFIER,
+        "Se esperaba el nombre de la funcion.")) {
+        return false;
+        }
+
+        if (!expect(parser, BL_LPAREN,
+            "Se esperaba '(' despues del nombre de la funcion.")) {
+            return false;
+            }
+
+            if (!check(parser, BL_RPAREN)) {
+                for (;;) {
+                    if (!expect(parser, BL_IDENTIFIER,
+                        "Se esperaba el nombre del parametro.")) {
+                        return false;
+                        }
+
+                        if (!expect(parser, BL_COLON,
+                            "Se esperaba ':' despues del nombre del parametro.")) {
+                            return false;
+                            }
+
+                            if (!parse_type(parser, false)) {
+                                return false;
+                            }
+
+                            if (!check(parser, BL_COMMA)) {
+                                break;
+                            }
+
+                            advance(parser);
+
+                            if (check(parser, BL_RPAREN)) {
+                                break;
+                            }
+                }
+            }
+
+            if (!expect(parser, BL_RPAREN,
+                "Se esperaba ')' despues de los parametros.")) {
+                return false;
+                }
+
+                if (check(parser, BL_ARROW)) {
+                    advance(parser);
+
+                    if (!parse_type(parser, true)) {
+                        return false;
+                    }
+                }
+
+                return parse_block(parser);
+}
+
+bool bl_parse(const BlToken *tokens, size_t count, BlParseError *error)
+{
+    if (tokens == NULL || count == 0 || error == NULL) {
+        return false;
+    }
+
+    memset(error, 0, sizeof *error);
+
+    Parser parser = {
+        .tokens = tokens,
+        .count = count,
+        .position = 0,
+        .error = error,
+        .failed = false
+    };
+
+    while (!check(&parser, BL_EOF) && !parser.failed) {
+        if (!check(&parser, BL_FN)) {
+            return fail_at(&parser, current(&parser), "E1001",
+                           "En el nivel superior solo se permiten funciones.");
+        }
+
+        if (!parse_function(&parser)) {
+            return false;
+        }
+    }
+
+    return !parser.failed && check(&parser, BL_EOF);
+}