Files
regorus/src/builtins/debugging.rs
Anand Krishnamoorthi 48982222c5 Ability to gather print statements (#179)
Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>
2024-03-11 16:44:05 -07:00

53 lines
1.4 KiB
Rust

// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.
use crate::ast::{Expr, Ref};
use crate::builtins;
use crate::lexer::Span;
use crate::value::Value;
use std::collections::HashMap;
use anyhow::{bail, Result};
// TODO: Should we avoid this limit?
const MAX_ARGS: u8 = std::u8::MAX;
pub fn register(m: &mut HashMap<&'static str, builtins::BuiltinFcn>) {
m.insert("print", (print, MAX_ARGS));
}
pub fn print_to_string(
span: &Span,
_params: &[Ref<Expr>],
args: &[Value],
_strict: bool,
) -> Result<String> {
if args.len() > MAX_ARGS as usize {
bail!(span.error("print supports up to 100 arguments"));
}
let mut msg = String::default();
for a in args {
match a {
Value::Undefined => msg += " <undefined>",
Value::String(s) => msg += &format!(" {s}"),
_ => msg += &format!(" {a}"),
};
}
Ok(msg)
}
// Symbol analyzer must ensure that vars used by print are defined before
// the print statement. Scheduler must ensure the above constraint.
// Additionally interpreter must allow undefined inputs to print.
fn print(span: &Span, params: &[Ref<Expr>], args: &[Value], strict: bool) -> Result<Value> {
let msg = print_to_string(span, params, args, strict)?;
if !msg.is_empty() {
eprintln!("{}", &msg[1..]);
}
Ok(Value::Bool(true))
}