All code in Minilang is executed within a state. Each state has the following properties:
- Type
Every state is also a valid Minilang value (so they can be passed as first class values).
- Caller
The state that called this state.
- Context
Every state has an associated context (which may be shared across states).
- run
The function to call in order to run this state.
See /api/types for precise C structure definition of states.
Minilang code is run using a simple stack based virtual machine. There is a single register called RESULT which holds the most recent result.
Frame Layout| Field | Notes |
|---|---|
| Common state fields | Every closure frame is a valid state |
| Source name | For error reporting and debugging |
| Next instruction | For resuming after a call returns |
| Saved stack top | For resuming after a call returns |
| Current error handler | |
| Upvalues | For nested closures |
| Flags | |
| Schedule | For preemptive task switching |
| Debug state | Only present if frame is being debugged |
| Stack0 | Bottom of stack |
| Top of stack points to somewhere in this | |
| Stackn | Maximum stack |
| Instruction | Parameters | Description |
|---|---|---|
| RETURN | none | Switches to the calling state, passing the current value of RESULT. |
| SUSPEND | ||
| RESUME | ||
| NIL | ||
| SOME | ||
| IF | ||
| ELSE | ||
| PUSH | ||
| WITH | ||
| WITH_VAR | ||
| WITHX | ||
| POP | ||
| ENTER | ||
| EXIT | ||
| LOOP | ||
| TRY | ||
| CATCH | ||
| LOAD | ||
| LOAD_PUSH | ||
| VAR | ||
| VARX | ||
| LET | ||
| LETI | ||
| LETX | ||
| FOR | ||
| NEXT | ||
| VALUE | ||
| KEY | ||
| CALL | ||
| CONST_CALL | ||
| ASSIGN | ||
| LOCAL | ||
| LOCAL_PUSH | ||
| UPVALUE | ||
| LOCALX | ||
| TUPLE_NEW | ||
| TUPLE_SET | ||
| LIST_NEW | ||
| LIST_APPEND | ||
| MAP_NEW | ||
| MAP_INSERT | ||
| CLOSURE | ||
| PARTIAL_NEW | ||
| PARTIAL_SET |