leaf/src/parser/util.rs

89 lines
3.3 KiB
Rust

use std::fmt::Write;
use crate::parser::Expr;
pub fn display(e: &Expr) {
let result = fmt_expr(e, 0);
println!("{result}");
}
fn fmt_binop(left: &Expr, right: &Expr, op: &str, depth: usize) -> String {
format!(
"({} {} {})",
fmt_expr(left, depth),
op,
fmt_expr(right, depth)
)
}
fn fmt_expr(e: &Expr, depth: usize) -> String {
match e {
Expr::Assign(l, r) => fmt_binop(l, r, "=", depth),
Expr::AddAssign(l, r) => fmt_binop(l, r, "+=", depth),
Expr::SubtractAssign(l, r) => fmt_binop(l, r, "-=", depth),
Expr::MultiplyAssign(l, r) => fmt_binop(l, r, "*=", depth),
Expr::DivideAssign(l, r) => fmt_binop(l, r, "/=", depth),
Expr::Literal(l) => l.to_string(),
Expr::Call(l, r) => {
let mut result = fmt_expr(l, depth);
result.push('(');
let len = r.len();
for (i, e) in r.into_iter().enumerate() {
result.push_str(&fmt_expr(e, depth));
if i + 1 != len {
result.push_str(", ");
}
}
result.push(')');
result
}
Expr::If(c, t, f) => {
let mut result = format!("if ({}) ({})", fmt_expr(c, depth), fmt_expr(t, depth));
if let Some(f) = f {
let _ = write!(result, " else ({})", fmt_expr(f, depth));
}
result
}
Expr::Return(l) => format!("return ({})", fmt_expr(l, depth)),
Expr::Block(b) => {
let mut result = String::new();
let len = b.exprs.len();
for (i, expr) in b.exprs.iter().enumerate() {
result.push_str(&" ".repeat(depth));
result.push_str(&fmt_expr(expr, depth + 1));
if depth != 0 || i + 1 != len {
result.push('\n');
}
}
if depth != 0 {
result = format!("{{\n{result}{}}}", " ".repeat(depth - 1));
}
result
}
Expr::Func(a, e) => format!(
"(func({}) ({}))",
a.into_iter()
.map(|e| fmt_expr(e, depth))
.collect::<Vec<_>>()
.join(", "),
fmt_expr(e, depth)
),
Expr::Negate(l) => format!("(-{})", fmt_expr(l, depth)),
Expr::Not(l) => format!("(!{})", fmt_expr(l, depth)),
Expr::EqualTo(l, r) => fmt_binop(l, r, "==", depth),
Expr::NotEqualTo(l, r) => fmt_binop(l, r, "!=", depth),
Expr::And(l, r) => fmt_binop(l, r, "&&", depth),
Expr::Or(l, r) => fmt_binop(l, r, "||", depth),
Expr::LessThan(l, r) => fmt_binop(l, r, "<", depth),
Expr::LessThanOrEqualTo(l, r) => fmt_binop(l, r, "<=", depth),
Expr::GreaterThan(l, r) => fmt_binop(l, r, ">", depth),
Expr::GreaterThanOrEqualTo(l, r) => fmt_binop(l, r, ">=", depth),
Expr::Add(l, r) => fmt_binop(l, r, "+", depth),
Expr::Subtract(l, r) => fmt_binop(l, r, "-", depth),
Expr::Multiply(l, r) => fmt_binop(l, r, "*", depth),
Expr::Divide(l, r) => fmt_binop(l, r, "/", depth),
Expr::Exponent(l, r) => fmt_binop(l, r, "**", depth),
Expr::Modulo(l, r) => fmt_binop(l, r, "%", depth),
}
}