implemented str_slice

include/tlibc/collections/Array.h

@@ -38,11 +38,12 @@ static inline Array_ Array_copy(Array_ src){
 
 #define struct_castTo_Array(STRUCT_PTR) Array_construct_size((STRUCT_PTR), sizeof(*STRUCT_PTR))
 
+///@return a[0..n]
 static inline Array(u8) Array_sliceBefore(Array(u8) a, u32 n){
     return Array_construct_size(a.data, n);
 }
 
-
+///@return a[n...]
 static inline Array(u8) Array_sliceAfter(Array(u8) a, u32 n){
     return Array_construct_size((u8*)a.data + n, a.size - n);
 }

include/tlibc/errors.h

@@ -93,4 +93,4 @@ typedef struct Result_ {
     }\
 } while(0)
 
-#define try_assert(EXPR) if(!(EXPR)) { Return RESULT_ERROR((#EXPR), false); } 
+#define try_assert(EXPR) if(!(EXPR)) { Return RESULT_ERROR(("try_assert(" #EXPR ")"), false); } 

include/tlibc/filesystem.h

@@ -62,6 +62,10 @@ Result(FILE*) file_open(cstr file_name, cstr fopen_mode);
 Result(FILE*) file_openOrCreateReadWrite(cstr file_name);
 
 bool file_exists(cstr path);
+
+///@return current position in file
+Result(i64) file_tellPos(FILE* f);
+///@return total size of file
 Result(i64) file_getSize(FILE* f);
 
 
@@ -71,6 +75,7 @@ typedef enum SeekOrigin {
     SeekOrigin_End = SEEK_END,
 } SeekOrigin;
 
+/// @brief changes current position in file 
 Result(void) file_seek(FILE* f, i64 offset, SeekOrigin origin);
 
 

include/tlibc/string/str.h

@@ -59,3 +59,14 @@ str hex_to_str(Array(u8) buf, bool uppercase);
 
 /// @brief removes blank characters from start and end of the line
 void str_trim(str* line, bool set_zero_at_end);
+
+
+///@return s[0..n]
+static inline str str_sliceBefore(str s, u32 n){
+    return str_construct(s.data, n, false);
+}
+
+///@return s[n...]
+static inline str str_sliceAfter(str s, u32 n){
+    return str_construct(s.data + n, s.size - n, s.isZeroTerminated);
+}

src/filesystem/file.c

@@ -47,7 +47,7 @@ Result(FILE*) file_openOrCreateReadWrite(cstr file_name){
 
 
 
-Result(i64) file_getSize(FILE* f){
+Result(i64) file_tellPos(FILE* f){
     i64 r = IFWIN(_ftelli64, ftello64)(f);
     if(r < 0){
         return RESULT_ERROR_ERRNO();
@@ -64,6 +64,18 @@ Result(void) file_seek(FILE* f, i64 offset, SeekOrigin origin){
     return RESULT_VOID;
 }
 
+Result(i64) file_getSize(FILE* f){
+    Deferral(4);
+    // get current position
+    try(i64 original_pos, i, file_tellPos(f));
+    // seek to end
+    try_void(file_seek(f, 0, SeekOrigin_End));
+    try(i64 size, i, file_tellPos(f));
+    // restore original position
+    try_void(file_seek(f, original_pos, SeekOrigin_Start));
+    Return RESULT_VALUE(i, size);
+}
+
 
 Result(void) file_writeStructs(FILE* f, const void* src, u64 struct_size, u64 count){
     u64 r = fwrite(src, struct_size, count, f);