# `sourcefile`
A library for concatenating source from multiple files, whilst keeping track of where each new file
and line starts.
# Examples
Assume the following file is at `partial1.py`
```python
x = 1
y = 1
```
and that the following file is at `partial2.py`
```python
x = 1
y = 1 oops
```
then the following code
```rust
extern crate sourcefile;
use sourcefile::SourceFile;
// Assume this function exists, error is offset of unexpected char.
fn parse(source: &str) -> Result<Ast, usize> {
// ...
}
fn main() {
let mut source = SourceFile::new();
source = source.add_file("./partial1.py");
source = source.add_file("./partial2.py");
let ast = match parse(&source.content) {
Ok(ast) => ast,
Err(offset) => {
let pos = source.resolve_offset(offset);
eprintln!("error compiling in \"{}\", line {}, col {}.",
pos.filename, pos.line + 1, pos.col + 1);
}
}
}
```
prints
```text
error compiling in "./partial2.py", line 2, col 7.
```