diff --git a/README.md b/README.md index 8a4e94a..9aa89b3 100644 --- a/README.md +++ b/README.md @@ -1,25 +1,27 @@ # interpreter -*interpreter* is a minimal scripting language aimed at low-spec embedded systems. +*interpreter* is a minimal scripting language aimed at low-memory embedded systems. -Many other scripting languages currently exist for embedded use, including Lua, Tcl, and BASIC; however, their implementations require certain system calls (e.g. read()/write()) that may not be available or used on an embedded device. As a result, *interpreter* was made with the goal to allow advanced scripts to be run in minimal conditions. This included things like having only a few built-in functions, and only loading script from C-strings one at a time. +Many other scripting languages currently exist for embedded use, including Lua, Tcl, and BASIC; however, their implementations require certain system calls (e.g. read()/write()) that may not be available or used on an embedded device. Additionally, their memory and/or non-volatile memory requirements may be too large for the targeted device. As a result, *interpreter* was made with the goal to allow advanced scripts to be run in minimal conditions. This included things like having only a few built-in functions, and only loading script from C-strings. To use *interpreter* with your own device, you will need some malloc/free implementation and a freestanding standard library. Newlib can work well for this, although functions like atoi() and snprintf() will probably need to be rewritten (if you don't have an \_sbrk defined). ### interpreter features: * Variable/function definition - in C and in script +* dynamic arrays * if/else conditionals * while loops * a solve function to parse strings at script runtime ### inconvenient features: * some code formatting is enforced due to parser limitation -* all variables are global +* all variables are global (i.e. scopes don't exist) * whitespace is not always ignored ### some TODO items: * add better error messages * better array support +* better string support * for loops * variable scopes @@ -27,9 +29,9 @@ To use *interpreter* with your own device, you will need some malloc/free implem This project can be made for the host system (```mv shell.c.bak shell.c; make```) or an ARM system (```mv shell.c shell.c.bak; make arm```). Make's ```-j``` argument may be used to multithread compilation. -To run on the host system, run ```./shell some_script_file```. Note that no IO functions are built in, so you must define your own. +To run on the host system, run ```./shell some_script_file```. Note that IO functions are **not** built in, so you must define your own. To use on an ARM device, simply link ```libinterp.a``` into your program and use the header files. See ```shell.c``` for an idea of how to the interpreter.   -This project is still in heavy development, so don't expect too much. See the wiki for a scripting guide. +This project is still in heavy development, so don't expect too much. See the wiki for a scripting guide.