New features:

• Allow pattern matching on multiple values.
• Add io.setformat, which allows us to set a default format for all echo statements.
• Add str->partition.
• Add format option for echo.
• Allow = syntax in tables.
• Add 'b' option to bool->tostr.
• Add bool->tobyte.
• Add table->setdefault.

C API:

• Add function to allow us to disable echo from the C API.
• Add YASL_getvargsstart to get us the starting index of the variadic arguments.
• Add YASL_floattostr to convert floats to string in the same way as float->tostr.

New Features:

• list->search and str->search now takes an additional optional parameter (the starting position).
• str->search now returns the end position of the found str (as well as the start).
• Allow no trailing new line at end of files.
• Add eval function.
• Add math.log2 and math.log10.

Bug Fixes:

• Fix bug with calling str->trim(whitespace).
• Clean up how io handles files with newlines on Windows.
• Fix error messages for all bool methods.
• Fix error where ref counting in upvals was not done correctly in some cases.

Internal Changes:

• Clean up directory structure
• Clean up tests for errors
• Start preliminary work on GC.

New Features:

• Added try function to allow recovery from errors.
• Add package.searchpath, to allow us to see what files we attempt to open with require.
• Add list->shuffle, to allow randomly reordering a list.
• Add list->has, str->has, and set->has for checking membership.

Bug Fixes:

• Slicing with invalid range now correctly shows error message instead of crashing.
• Fixed bug with str->replace(str, str, int) incorrectly not doing enough replacements.
• table->copy now correctly copies the metatable.

C API:

• Add YASLX_checknoptstrz, for checking for str/undef and filling in a default value.
• Deprecate YASL_popcstr, YASL_peekuserdata, and YASL_popuserdata.

Internal Changes:

• Most strs are now interned.

New Features:

• Add str.isupper and str.islower.
• Allow list.sort(fn), for sorting with a custom function.
• Add io.tmpfile.

Bug Fixes:

• str.count('') now returns the string length + 1.
• str.split('', int) is now correctly an error.
• str.split(0) now correctly handles leading whitespace.
• Fix bug with io.write crashing.

New Features:

• Add os.command, for running shell commands directly from YASL.
• Add os.clock, for getting approximate time since program start.
• Add os.getenv, for loading environment variables from YASL.

Bug Fixes:

• Correctly handle syntax errors with variables declared using -D flag.
• str.split(int) now correctly returns a list of length 1 when no splits occur.
• str.split(int) now correctly handles whitespace after the last split.
• str.split(0) no longer returns an empty list.

C API:

• Add YASLX_print_value_err.
• Add YASLX_print_err_bad_arg_type_n, to cut down on boilerplate with YASLX_print_err_bad_arg_type.
• Add YASLX_throw_value_err and YASLX_throw_type_err, to cut down on boilerplate with YASL_throw_err.
• Add YASLX_checknoptint, YASLX_checknoptfloat, YASLX_checknoptbool for checking if a value is the specific type or undef.
• Add YASL_checknstr.

Bug Fixes:

• Fixed bug introduced in v0.13.1 that caused incorrect handling of commandline arguments.
• Fixed crash when there is a syntax error while using the -D flag.
• Added function declarations for a few missing functions in yasl.h.

New Features:

• Allow formatting of expressions in interpolated strings.
• Allow defining global variables from the command line with the -D flag.

Bug Fixes:

• YASL_callfunction now works correctly with YASL functions (rather than only with C ones).
• return in the body of a match in a variadic function now works correctly.
• Fixed bug with comparison operators causing a crash when used with list, table, and set literals.

Breaking Changes:

• Add asserts to validate that global variables are valid YASL identifiers (previously allowed any string, which would be impossible to use if not a valid YASL identifier).
• list->search now looks from start of list (previously, looked from end due to bug).
• . no longer looks in the metatable.
• collections.table no longer adds an extra undef, instead it removes the last argument, so it matches with the literal table constructors better.
• (variadic) (a variadic pack surrounded by parentheses) now decays to a single expression.
• Short lambdas fn(...) -> ... no longer allow parentheses around the return for variadics.
• Only allow looking up metatables via mt.get for table, list, and userdata.
• Iteration now uses in instead of <-.

New Features:

• Add int->tochar and str->tobyte functions, to allow turning numeric codes to strings and vice-versa (e.g. a -> 97 and vice-versa).
• Add 'r', 'd', 'x', and 'b' formats for int->tostr.
• Add 'r' format to str->tostr.
• Forward format args for list->tostr, set->tostr, and table->tostr to their elements.
• Add str->isprint function to check for printable characters.

C API:

• Add YASLX_tablesetfunctions to allow adding multiple functions at once to a table from C.

Bug Fixes:

• YASLX_checknint and YASLX_checknfloat now correctly print out the type of the incorrect argument (previously, they always printed the type of the top of the stack).
• Fix bug with writing str containing '\0' to a file (previously, we used the C function strlen for this, resulting in incorrectly writing too short of a length).

Other Changes:

• Allow pure, consteval, constexpr, constfold and yield as identifier names (previously, they were reserved).

Bug Fixes:

• Fix Unicode output on Windows.

New Features:

• Add max_splits argument to str.split, to allow only splitting up to a certain number of times.
• Add mt.setself function.
• Add mt.lookup function.

Bug Fixes:

• Fixes bug where comprehension not used as the only expression on the stack produced wrong result.
• Fix handling of files using only LF on Windows.

Internal Changes:

• Update tests to use mt.lookup.