Also fixed a minor bug with printing, and removed the ability to
configure the parser.
Added and updated QUICKSTART.md as a quick way to get people started.
There's some broken scripts under 'scripts/' that require functions to
work properly.
I've ripped out the deep copying, and flattened the bucket usage, but
this results in no memory being freed or reused for the lifetime of the
program.
This is shown most clearly with this script:
```toy
fn makeCounter() {
var counter: int = 0;
fn increment() {
return ++counter;
}
return increment;
}
var tally = makeCounter();
while (true) {
var result = tally();
if (result >= 10_000_000) {
break;
}
}
```
The number of calls vs amount of memory consumed is:
```
function calls -> memory used in megabytes
1_000 -> 0.138128
10_000 -> 2.235536
100_000 -> 21.7021
1_000_000 -> 216.1712
10_000_000 -> 1520.823
```
Obviously this needs to be fixed, as ballooning to gigabytes of memory
in only a moment isn't practical. That will be the next task - to find
some way to free memory that isn't needed anymore.
See #163, #160
I build a self-referential system, then tried to copy only parts. I need
to step back and adjust my approach.
'Toy_private_deepCopyValue' and 'Toy_private_deepCopyScope' need to be
ripped out, and I need to simply accept there will be only one instance
of 'Toy_Bucket' that isn't freed until the top-level VM is.
I need an hour's break before I'll tackle this again.
See #163
Functions are having issues with being copied around, especially
between buckets, leading to the scopes getting looped. The program gets
stuck in 'incrementRefCount()'.
It's past my time limit, so I'll keep working on it tomorrow with a
fresh mind.
All function stuff is still untested.
See #163
If a string exists in the data, instead of being written, the function
'emitCStringToData()' will instead return the address of the match
within the data section.
Then, I can search the jump table for that address, and use the existing
jump entry or append a new one.
Fixes#168
Parameter lists are read manually, rather than delegating to
parsePrecedence, because that was causing issues.
function bodies are read as block-level statements, just like the entire
files.
They're no-ops in compilation for now, and param types aren't parsed.
'return' keyword needs to be implemented.
Was distracted by bugfixes in v2 and v2-docs.
The 'source' directory compiles, but the repl and tests are almost
untouched so far. There's no guarantee that the code in 'source' is
correct, so I'm branching this for a short time, until I'm confident the
whole project passes the CI again.
I'm adjusting the concepts of routines and bytecode to make them more
consistent, and tweaking the VM so it loads from an instance of
'Toy_Module'.
* 'Toy_ModuleBuilder' (formally 'Toy_Routine')
This is where the AST is compiled, producing a chunk of memory that can
be read by the VM. This will eventually operate on individual
user-defined functions as well.
* 'Toy_ModuleBundle' (formally 'Toy_Bytecode')
This collects one or more otherwise unrelated modules into one chunk of
memory, stored in sequence. It is also preprended with the version data for
Toy's reference implementation:
For each byte in the bytecode:
0th: TOY_VERSION_MAJOR
1st: TOY_VERSION_MINOR
2nd: TOY_VERSION_PATCH
3rd: (the number of modules in the bundle)
4th and onwards: TOY_VERSION_BUILD
TOY_VERSION_BUILD has always been a null terminated C-string, but from
here on, it begins at the word-alignment, and continues until the first
word-alignment after the null terminator.
As for the 3rd byte listed, since having more than 256 modules in one
bundle seems unlikely, I'm storing the count here, as it was otherwise
unused. This is a bit janky, but it works for now.
* 'Toy_Module'
This new structure represents a single complete unit of operation, such
as a single source file, or a user-defined function. It is divided into
three main sections, with various sub-sections.
HEADER (all members are unsigned ints):
total module size in bytes
jumps count
param count
data count
subs count
code addr
jumps addr (if jumps count > 0)
param addr (if param count > 0)
data addr (if data count > 0)
subs addr (if subs count > 0)
BODY:
<raw opcodes, etc.>
DATA:
jumps table
uint array, pointing to addresses in 'data' or 'subs'
param table
uint array, pointing to addresses in 'data'
data
heterogeneous data, including strings
subs
an array of modules, using recursive logic
The reference implementation as a whole uses a lot of recursion, so this
makes sense.
The goal of this rework is so 'Toy_Module' can be added as a member of
'Toy_Value', as a simple and logical way to handle functions. I'll
probably use the union pattern, similarly to Toy_String, so functions
can be written in C and Toy, and used without needing to worry which is
which.
Variable declaration was also causing this issue.
It was caused by a value being left on the stack after these statements.
It wasn't a quick fix, as chained assignments depended on it. Now, the
assignment opcode has a configuration option, indicating if the last
value should be left on the stack or not.
This also means the benchmark in 'scripts/benchpress.toy' will no longer
cause a stack overflow.
Fixed#171
