about summary refs log tree commit diff
path: root/tvix/eval/src/eval.rs
blob: e6199e00b0e2b815497dfd32d8642b9777f1b608 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
use std::{path::PathBuf, rc::Rc};

use crate::{
    builtins::global_builtins,
    errors::{Error, ErrorKind, EvalResult},
    observer::{DisassemblingObserver, NoOpObserver, TracingObserver},
    value::Value,
};

/// Runtime options for the Tvix interpreter
#[derive(Debug, Clone, Copy, Default)]
#[cfg_attr(feature = "repl", derive(clap::Parser))]
pub struct Options {
    /// Dump the raw AST to stdout before interpreting
    #[cfg_attr(feature = "repl", clap(long, env = "TVIX_DISPLAY_AST"))]
    display_ast: bool,

    /// Dump the bytecode to stdout before evaluating
    #[cfg_attr(feature = "repl", clap(long, env = "TVIX_DUMP_BYTECODE"))]
    dump_bytecode: bool,

    /// Trace the runtime of the VM
    #[cfg_attr(feature = "repl", clap(long, env = "TVIX_TRACE_RUNTIME"))]
    trace_runtime: bool,
}

pub fn interpret(code: &str, location: Option<PathBuf>, options: Options) -> EvalResult<Value> {
    let mut codemap = codemap::CodeMap::new();
    let file = codemap.add_file(
        location
            .as_ref()
            .map(|p| p.to_string_lossy().to_string())
            .unwrap_or_else(|| "[tvix-repl]".into()),
        code.into(),
    );
    let codemap = Rc::new(codemap);

    let parsed = rnix::ast::Root::parse(code);
    let errors = parsed.errors();

    if !errors.is_empty() {
        for err in errors {
            eprintln!("parse error: {}", err);
        }
        return Err(Error {
            kind: ErrorKind::ParseErrors(errors.to_vec()),
            span: file.span,
        });
    }

    // If we've reached this point, there are no errors.
    let root_expr = parsed
        .tree()
        .expr()
        .expect("expression should exist if no errors occured");

    if options.display_ast {
        println!("{:?}", root_expr);
    }

    let result = if options.dump_bytecode {
        crate::compiler::compile(
            root_expr,
            location,
            file.clone(),
            global_builtins(),
            &mut DisassemblingObserver::new(codemap.clone(), std::io::stderr()),
        )
    } else {
        crate::compiler::compile(
            root_expr,
            location,
            file.clone(),
            global_builtins(),
            &mut NoOpObserver::default(),
        )
    }?;

    for warning in result.warnings {
        warning.fancy_format_stderr(&codemap);
    }

    for error in &result.errors {
        error.fancy_format_stderr(&codemap);
    }

    if let Some(err) = result.errors.last() {
        return Err(err.clone());
    }

    let result = if options.trace_runtime {
        crate::vm::run_lambda(&mut TracingObserver::new(std::io::stderr()), result.lambda)
    } else {
        crate::vm::run_lambda(&mut NoOpObserver::default(), result.lambda)
    };

    if let Err(err) = &result {
        err.fancy_format_stderr(&codemap);
    }

    result
}