add better string and number parsing to sexp. cleaning, more tests

pull/21/head
Ondřej Hruška 4 years ago
parent 548addc78c
commit 1f2dbaa81d
Signed by: MightyPork
GPG Key ID: 2C5FD5035250423D
  1. 4
      README.md
  2. 2
      crsn/Cargo.toml
  3. 0
      crsn/crsn-sexp/.gitignore
  4. 0
      crsn/crsn-sexp/Cargo.toml
  5. 1
      crsn/crsn-sexp/LICENSE
  6. 19
      crsn/crsn-sexp/README.md
  7. 12
      crsn/crsn-sexp/src/error.rs
  8. 444
      crsn/crsn-sexp/src/lib.rs
  9. 45
      crsn/crsn-sexp/src/test.rs
  10. 72
      crsn/src/asm/parse/parse_data.rs
  11. 24
      crsn/src/asm/parse/sexp_expect.rs
  12. 2
      crsn/src/builtin/defs.rs
  13. 2
      crsn/src/builtin/exec.rs
  14. 22
      crsn/src/builtin/parse.rs
  15. 1
      crsn/src/lib.rs
  16. 9
      crsn/src/utils/mod.rs
  17. 6
      crsn_stdio/src/lib.rs
  18. 2
      examples/stacks.csn
  19. 10
      examples/stdio.csn
  20. 24
      launcher/src/main.rs
  21. 9
      lib/spanned_sexp/README.md
  22. 324
      lib/spanned_sexp/src/lib.rs

@ -374,7 +374,7 @@ Many instructions have two forms:
(asl DST B) (asl DST B)
; Delete an object by its handle. Objects are used by some extensions. ; Delete an object by its handle. Objects are used by some extensions.
(drop @REG) (del @REG)
``` ```
## Stacks Module ## Stacks Module
@ -398,7 +398,7 @@ This module defines data stacks. Stacks can be shared by routines by passing a h
(rpop DST @REG) (rpop DST @REG)
``` ```
To delete a stack, drop its handle - `(drop @REG)` To delete a stack, use the `del` instruction - `(del @REG)`
## Screen module ## Screen module

@ -6,7 +6,7 @@ edition = "2018"
publish = false publish = false
[dependencies] [dependencies]
sexp = { path = "../lib/spanned_sexp" } sexp = { path = "crsn-sexp" }
thiserror = "1.0.20" thiserror = "1.0.20"
anyhow = "1.0.32" anyhow = "1.0.32"
dyn-clonable = "0.9.0" dyn-clonable = "0.9.0"

@ -1,4 +1,5 @@
Copyright (c) 2015 Clark Gaebel <cg.wowus.cg@gmail.com> Copyright (c) 2015 Clark Gaebel <cg.wowus.cg@gmail.com>
Copyright (c) 2020 Ondřej Hruška <ondra@ondrovo.com>
Permission is hereby granted, free of charge, to any person obtaining a copy Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal of this software and associated documentation files (the "Software"), to deal

@ -0,0 +1,19 @@
CRSN Sexp
=========
This is an updated and extended version of the "sexp" crate by Clark Gaebel: [https://github.com/cgaebel/sexp](https://github.com/cgaebel/sexp).
## Changes from "cgaebel/sexp"
- Updated to the 2018 Rust edition (that is, removed `try!()` and such)
- All parsed atoms now track their source location. This enables better error reporting in subsequent parsing and processing.
- Quoted strings now support C-style escapes other than `\"`, such as `\n`, `\t` and `\\`.
- Unrecognized escapes result in the slash being removed and the next character being taken literally. Use `\\` to enter a backslash.
- Added special parsing of "character literals" that use single quotes (`'A'`) and may contain backslash escapes (`'\n'`).
- This does not interfere with "apostrophe tokens" like `'foo`, that becomes an unquoted string atom.
- Added "quoted string", "unsigned" and "character" atom types
- Added parsing for `0x123`, `#ff00ff` and `0b123456`
- Numeric literals may now contain underscores to separate digit groups
- Numbers are preferably parsed as the unsigned atom (u64). The signed atom (i64) is only used for negative numbers.
.

@ -63,23 +63,23 @@ pub(crate) fn get_line_and_column(s: &str, pos: usize) -> SourcePosition {
} }
#[cold] #[cold]
fn err_impl(message: &'static str, s: &str, pos: &usize) -> Err { fn err_impl(message: &'static str, s: &str, pos: usize) -> Err {
Box::new(Error { Box::new(Error {
message, message,
pos: get_line_and_column(s, *pos), pos: get_line_and_column(s, pos),
}) })
} }
/// Build an error with span information /// Build an error with span information
pub(crate) fn err<T>(message: &'static str, s: &str, pos: &usize) -> ERes<T> { pub(crate) fn err<T>(message: &'static str, s: &str, pos: usize) -> ERes<T> {
Err(err_impl(message, s, pos)) Err(err_impl(message, s, pos))
} }
/// Build a span /// Build a span
pub(crate) fn spos(s: &str, pos: &usize) -> SourcePosition { pub(crate) fn spos(s: &str, pos: usize) -> SourcePosition {
if *pos >= s.len() { if pos >= s.len() {
Default::default() Default::default()
} else { } else {
get_line_and_column(s, *pos) get_line_and_column(s, pos)
} }
} }

@ -0,0 +1,444 @@
//! A lightweight, self-contained s-expression parser and data format.
//! Use `parse` to get an s-expression from its string representation, and the
//! `Display` trait to serialize it, potentially by doing `sexp.to_string()`.
#![deny(unsafe_code)]
#[macro_use]
extern crate log;
use std::borrow::Cow;
use std::fmt;
use std::str::{self, FromStr};
use error::{ERes, err, spos};
pub use error::Error;
pub use error::SourcePosition;
#[cfg(test)]
mod test;
mod error;
/// A single data element in an s-expression. Floats are excluded to ensure
/// atoms may be used as keys in ordered and hashed data structures.
///
/// All strings must be valid utf-8.
#[derive(Debug, PartialEq, Clone, PartialOrd)]
pub enum Atom {
/// Simple string atom
S(String),
/// Quoted string
QS(String),
/// Character literal (with single quotes)
C(char),
/// Signed integer (normally only used for negative values)
I(i64),
/// Unsigned integer
U(u64),
/// Float
F(f64),
}
/// An s-expression is either an atom or a list of s-expressions. This is
/// similar to the data format used by lisp.
#[derive(Debug, Clone)]
pub enum Sexp {
/// Atom
Atom(Atom, SourcePosition),
/// List of expressions
List(Vec<Sexp>, SourcePosition),
}
impl Sexp {
pub fn pos(&self) -> &SourcePosition {
match self {
Sexp::List(_, pos) | Sexp::Atom(_, pos) => pos
}
}
/// Check fi thsi Sexp is an atom
pub fn is_atom(&self) -> bool {
match self {
Sexp::Atom(_, _) => true,
_ => false,
}
}
/// Check fi thsi Sexp is a list
pub fn is_list(&self) -> bool {
match self {
Sexp::List(_, _) => true,
_ => false,
}
}
}
impl PartialEq for Sexp {
fn eq(&self, other: &Self) -> bool {
match (self, other) {
(Sexp::Atom(a, _), Sexp::Atom(b, _)) => {
a == b
}
(Sexp::List(a, _), Sexp::List(b, _)) => {
a == b
}
_ => false
}
}
}
fn without_underscores(s: &str) -> Cow<str> {
if s.contains('_') {
s.chars()
.filter(|c| *c != '_')
.collect::<String>().into()
} else {
s.into()
}
}
fn atom_of_string(s: String) -> Atom {
if s.starts_with('#') {
match u64::from_str_radix(&without_underscores(&s[1..]), 16) {
Ok(u) => return Atom::U(u),
Err(_) => {}
};
}
if s.starts_with("0x") {
match u64::from_str_radix(&without_underscores(&s[2..]), 16) {
Ok(u) => return Atom::U(u),
Err(_) => {}
};
}
if s.starts_with("0b") {
match u64::from_str_radix(&without_underscores(&s[2..]), 2) {
Ok(u) => return Atom::U(u),
Err(_) => {}
};
}
if !s.starts_with('_') {
let filtered = without_underscores(&s);
match FromStr::from_str(&filtered) {
Ok(u) => return Atom::U(u),
Err(_) => {}
};
match FromStr::from_str(&filtered) {
Ok(i) => return Atom::I(i),
Err(_) => {}
};
match FromStr::from_str(&filtered) {
Ok(f) => return Atom::F(f),
Err(_) => {}
};
}
Atom::S(s)
}
// returns the char it found, and the new pos if you wish to consume that char
fn peek(s: &str, pos: usize) -> ERes<(char, usize)> {
trace!("peek {}", pos);
if pos == s.len() { return err("unexpected eof", s, pos); }
if s.is_char_boundary(pos) {
let ch = s[pos..].chars().next().unwrap();
let next = pos + ch.len_utf8();
Ok((ch, next))
} else {
// strings must be composed of valid utf-8 chars.
unreachable!()
}
}
// returns the char it found, and the new pos if you wish to consume that char
fn peekn(s: &str, nth: usize, pos: usize) -> Option<(char, usize)> {
trace!("peekn {}", pos);
if nth == 0 {
panic!("peekn with nth=0");
}
if s.is_char_boundary(pos) {
let mut iter = s[pos..].chars();
let mut bytelen = 0;
for n in 0..nth {
if let Some(ch) = iter.next() {
bytelen += ch.len_utf8();
if n == (nth - 1) {
return Some((ch, pos + bytelen));
}
} else {
return None;
}
}
unreachable!()
} else {
// strings must be composed of valid utf-8 chars.
unreachable!()
}
}
fn expect(s: &str, pos: &mut usize, c: char) -> ERes<()> {
trace!("expect {}", pos);
let (ch, next) = peek(s, *pos)?;
*pos = next;
if ch == c {
Ok(())
} else {
err("unexpected character", s, *pos)
}
}
fn consume_until_newline(s: &str, pos: &mut usize) -> ERes<()> {
loop {
if *pos == s.len() {
return Ok(());
}
let (ch, next) = peek(s, *pos)?;
*pos = next;
if ch == '\n' {
return Ok(());
}
}
}
// zero or more spaces
fn zspace(s: &str, pos: &mut usize) -> ERes<()> {
trace!("zspace {}", pos);
loop {
if *pos == s.len() {
return Ok(());
}
let (ch, next) = peek(s, *pos)?;
if ch == ';' {
consume_until_newline(s, pos)?
} else if ch.is_whitespace() {
*pos = next;
} else {
return Ok(());
}
}
}
fn parse_quoted_atom(s: &str, quote: char, pos: &mut usize) -> ERes<Atom> {
trace!("parse_quoted_atom {}", pos);
let pos0 = *pos;
let mut cs: String = String::new();
expect(s, pos, quote)?;
loop {
let (ch, next) = peek(s, *pos)?;
if ch == quote {
*pos = next;
break;
} else if ch == '\\' {
let (postslash, nextnext) = peek(s, next)?;
match postslash {
'r' => cs.push('\r'),
'n' => cs.push('\n'),
't' => cs.push('\t'),
other => cs.push(other)
}
*pos = nextnext;
} else {
cs.push(ch);
*pos = next;
}
}
if quote == '\'' {
// This is a character literal
if cs.chars().count() == 1 {
return Ok(Atom::C(cs.chars().next().unwrap()));
} else {
return err("Too long character literal!", s, pos0);
}
}
// Do not try i64 conversion, since this atom was explicitly quoted.
Ok(Atom::QS(cs))
}
fn parse_unquoted_atom(s: &str, pos: &mut usize) -> ERes<Atom> {
trace!("parse_unquoted_atom {}", pos);
let mut cs: String = String::new();
loop {
if *pos == s.len() { break; }
let (c, next) = peek(s, *pos)?;
if c == ';' {
consume_until_newline(s, pos)?;
break;
}
if c.is_whitespace() || c == '(' || c == ')' {
break;
}
cs.push(c);
*pos = next;
}
Ok(atom_of_string(cs))
}
fn parse_atom(s: &str, pos: &mut usize) -> ERes<Atom> {
trace!("parse_atom {}", pos);
let (ch, _) = peek(s, *pos)?;
if ch == '"' {
return parse_quoted_atom(s, ch, pos);
} else if ch == '\'' {
if let Some(('\\', _)) = peekn(s, 2, *pos) {
if let Some(('\'', _)) = peekn(s, 4, *pos) {
// Character literal with an escape sequence
return parse_quoted_atom(s, '\'', pos);
}
} else if let Some(('\'', _)) = peekn(s, 3, *pos) {
// Simple character literal
return parse_quoted_atom(s, '\'', pos);
}
}
parse_unquoted_atom(s, pos)
}
fn parse_list(s: &str, pos: &mut usize) -> ERes<Vec<Sexp>> {
trace!("parse_list {}", pos);
zspace(s, pos)?;
expect(s, pos, '(')?;
let mut sexps: Vec<Sexp> = Vec::new();
loop {
zspace(s, pos)?;
let (c, next) = peek(s, *pos)?;
if c == ')' {
*pos = next;
break;
}
sexps.push(parse_sexp(s, pos)?);
}
zspace(s, pos)?;
Ok(sexps)
}
fn parse_sexp(s: &str, pos: &mut usize) -> ERes<Sexp> {
trace!("parse_sexp {}", pos);
zspace(s, pos)?;
let (c, _) = peek(s, *pos)?;
let r = if c == '(' {
Ok(Sexp::List(parse_list(s, pos)?, spos(s, *pos)))
} else {
Ok(Sexp::Atom(parse_atom(s, pos)?, spos(s, *pos)))
};
zspace(s, pos)?;
r
}
/// Constructs an atomic s-expression from a string.
pub fn atom_s(s: &str) -> Sexp {
Sexp::Atom(Atom::S(s.to_owned()), Default::default())
}
/// Constructs an atomic s-expression from a string.
pub fn atom_qs(s: &str) -> Sexp {
Sexp::Atom(Atom::QS(s.to_owned()), Default::default())
}
/// Constructs an atomic s-expression from an int.
pub fn atom_i(i: i64) -> Sexp {
Sexp::Atom(Atom::I(i), Default::default())
}
/// Constructs an atomic s-expression from an unsigned int.
pub fn atom_u(u: u64) -> Sexp {
Sexp::Atom(Atom::U(u), Default::default())
}
/// Constructs an atomic s-expression from a char
pub fn atom_c(c: char) -> Sexp {
Sexp::Atom(Atom::C(c), Default::default())
}
/// Constructs an atomic s-expression from a float.
pub fn atom_f(f: f64) -> Sexp {
Sexp::Atom(Atom::F(f), Default::default())
}
/// Constructs a list s-expression given a slice of s-expressions.
pub fn list(xs: &[Sexp]) -> Sexp {
Sexp::List(xs.to_owned(), Default::default())
}
/// Reads an s-expression out of a `&str`.
#[inline(never)]
pub fn parse(s: &str) -> Result<Sexp, Box<Error>> {
let mut pos = 0;
let ret = parse_sexp(s, &mut pos)?;
if pos == s.len() {
Ok(ret)
} else {
err("unrecognized post-s-expression data", s, pos)
}
}
fn quote(s: &str) -> String {
s.chars().fold(String::new(), |mut s, ch| {
match ch {
'\'' | '\\' | '"' => {
s.push('\\');
s.push(ch);
}
'\n' => {
s.push_str("\\n");
}
'\r' => {
s.push_str("\\n");
}
'\t' => {
s.push_str("\\t");
}
other => {
s.push(other);
}
}
s
})
}
impl fmt::Display for Atom {
fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
match *self {
Atom::QS(ref s) => write!(f, "\"{}\"", quote(s)),
Atom::S(ref s) => write!(f, "{}", s),
Atom::C(c) => write!(f, "'{}'", quote(&c.to_string())),
Atom::I(i) => write!(f, "{}", i),
Atom::U(u) => write!(f, "{}", u),
Atom::F(d) => write!(f, "{}", d),
}
}
}
impl fmt::Display for Sexp {
fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
match *self {
Sexp::Atom(ref a, _) => write!(f, "{}", a),
Sexp::List(ref xs, _) => {
write!(f, "(")?;
for (i, x) in xs.iter().enumerate() {
let s = if i == 0 { "" } else { " " };
write!(f, "{}{}", s, x)?;
}
write!(f, ")")
}
}
}
}

@ -3,16 +3,33 @@ use super::error::get_line_and_column;
#[test] #[test]
fn test_hello_world() { fn test_hello_world() {
let parsed = parse("(hello #ffcc00 'c' ' ' '\\\\' '\\n' 'not_a_char 0xf_f 0b01_01 18_446_744_073_709_551_615 9223372036854775807 9223372036854775808 -42\n\t -4.0 \"world\") ; comment").unwrap();
assert_eq!( assert_eq!(
parse("(hello -42\n\t -4.0 \"world\") ; comment").unwrap(), parsed,
list(&[atom_s("hello"), atom_i(-42), atom_f(-4.0), atom_s("world")])); list(&[
atom_s("hello"),
atom_u(0xffcc00),
atom_c('c'),
atom_c(' '),
atom_c('\\'),
atom_c('\n'),
atom_s("'not_a_char"),
atom_u(255),
atom_u(0b0101),
atom_u(18_446_744_073_709_551_615),
atom_u(9223372036854775807),
atom_u(9223372036854775808),
atom_i(-42),
atom_f(-4.0),
atom_qs("world")
]));
} }
#[test] #[test]
fn test_escaping() { fn test_escaping() {
assert_eq!( assert_eq!(
parse("(\"\\\"\\q\" \"1234\" 1234)").unwrap(), parse(r#"("\"\\q\t\n\r " "1234" 1234)"#).unwrap(),
list(&[atom_s("\"\\q"), atom_s("1234"), atom_i(1234)])); list(&[atom_qs("\"\\q\t\n\r "), atom_qs("1234"), atom_u(1234)]));
} }
#[test] #[test]
@ -20,7 +37,7 @@ fn test_pp() {
let s = "(hello world (what is (up) (4 6.4 you \"123\\\\ \\\"\")))"; let s = "(hello world (what is (up) (4 6.4 you \"123\\\\ \\\"\")))";
let sexp = parse(s).unwrap(); let sexp = parse(s).unwrap();
assert_eq!(s, sexp.to_string()); assert_eq!(s, sexp.to_string());
assert_eq!(s, format!("{:?}", sexp)); assert_eq!(s, format!("{}", sexp));
} }
#[test] #[test]
@ -36,7 +53,7 @@ fn test_tight_parens() {
#[test] #[test]
fn test_space_in_atom() { fn test_space_in_atom() {
let sexp = list(&[atom_s("hello world")]); let sexp = list(&[atom_qs("hello world")]);
let sexp_as_string = sexp.to_string(); let sexp_as_string = sexp.to_string();
assert_eq!("(\"hello world\")", sexp_as_string); assert_eq!("(\"hello world\")", sexp_as_string);
assert_eq!(sexp, parse(&sexp_as_string).unwrap()); assert_eq!(sexp, parse(&sexp_as_string).unwrap());
@ -68,3 +85,19 @@ fn sexp_size() {
use std::mem; use std::mem;
assert_eq!(mem::size_of::<Sexp>(), mem::size_of::<isize>() * 6); assert_eq!(mem::size_of::<Sexp>(), mem::size_of::<isize>() * 6);
} }
#[test]
fn test_peek() {
assert_eq!(('a', 1), peek("ahoj", 0).unwrap());
assert_eq!(('j', 4), peek("ahoj", 3).unwrap());
assert!(peek("ahoj", 4).is_err());
}
#[test]
fn test_peekn() {
assert_eq!(Some(('a', 1)), peekn("ahoj", 1, 0));
assert_eq!(Some(('h', 2)), peekn("ahoj", 2, 0));
assert_eq!(Some(('j', 4)), peekn("ahoj", 4, 0));
assert_eq!(Some(('o', 3)), peekn("ahoj", 1, 2));
assert_eq!(None, peekn("ahoj", 3, 2));
}

@ -78,36 +78,26 @@ pub fn parse_data_disp(tok: Sexp, pcx: &ParserContext) -> Result<DataDisp, CrsnE
Sexp::Atom(Atom::I(val), _pos) => { Sexp::Atom(Atom::I(val), _pos) => {
Ok(DataDisp::Immediate(unsafe { std::mem::transmute(val) })) Ok(DataDisp::Immediate(unsafe { std::mem::transmute(val) }))
} }
Sexp::Atom(Atom::F(val), _pos) => {
Ok(DataDisp::Immediate(unsafe { std::mem::transmute(val) }))
}
Sexp::Atom(Atom::U(val), _pos) => {
Ok(DataDisp::Immediate(val))
}
Sexp::Atom(Atom::C(val), _pos) => {
Ok(DataDisp::Immediate(val as u64))
}
Sexp::Atom(Atom::QS(_s), pos) => {
Err(CrsnError::Parse("Quoted string not expected here".into(), pos))
}
Sexp::List(_list, pos) => {
Err(CrsnError::Parse("List not expected here".into(), pos))
}
Sexp::Atom(Atom::S(s), pos) => { Sexp::Atom(Atom::S(s), pos) => {
if s == "_" { if s == "_" {
return Ok(DataDisp::Discard); return Ok(DataDisp::Discard);
} }
if s.starts_with('\'') && s.ends_with('\'') {
if s.chars().count() == 3 {
let ch = s.chars().nth(1).unwrap();
if ch == '\'' {
return Err(CrsnError::Parse("Use '\\'' for apos".into(), pos));
}
return Ok(DataDisp::Immediate(ch as u64));
} else if s.chars().count() == 4 && s.chars().nth(1).unwrap() == '\\' {
let ch = s.chars().nth(2).unwrap();
let ch = match ch {
'\\' => '\\',
'n' => '\n',
'r' => '\r',
't' => '\t',
'\'' => '\'',
_ => {
return Err(CrsnError::Parse(format!("Unknown escape sequence: {}", s).into(), pos));
}
};
return Ok(DataDisp::Immediate(ch as u64));
} else {
return Err(CrsnError::Parse(format!("Invalid character literal synax {}", s).into(), pos));
}
}
if let Some(reference) = s.strip_prefix('@') { if let Some(reference) = s.strip_prefix('@') {
/* extension constants (pre-defined handles) */ /* extension constants (pre-defined handles) */
for p in pcx.parsers { for p in pcx.parsers {
@ -129,8 +119,6 @@ pub fn parse_data_disp(tok: Sexp, pcx: &ParserContext) -> Result<DataDisp, CrsnE
} else { } else {
Ok(DataDisp::RegObject(reg)) Ok(DataDisp::RegObject(reg))
} }
} else if s.starts_with(|c: char| c.is_ascii_digit() || c == '-') {
Ok(DataDisp::Immediate(unsafe { std::mem::transmute(parse_i64(&s, &pos)?) }))
} else { } else {
/* extension constants */ /* extension constants */
for p in pcx.parsers { for p in pcx.parsers {
@ -161,9 +149,6 @@ pub fn parse_data_disp(tok: Sexp, pcx: &ParserContext) -> Result<DataDisp, CrsnE
} }
} }
} }
other => {
Err(CrsnError::Parse(format!("bad data disp: {:?}", other).into(), other.pos().clone()))
}
} }
} }
@ -173,16 +158,28 @@ pub fn parse_value(tok: Sexp, pcx: &ParserContext) -> Result<Value, CrsnError> {
Sexp::Atom(Atom::I(val), _pos) => { Sexp::Atom(Atom::I(val), _pos) => {
Ok(unsafe { std::mem::transmute(val) }) Ok(unsafe { std::mem::transmute(val) })
} }
Sexp::Atom(Atom::U(val), _pos) => {
Ok(val)
}
Sexp::Atom(Atom::C(val), _pos) => {
Ok(val as u64)
}
Sexp::Atom(Atom::QS(_), pos) => {
Err(CrsnError::Parse("quoted string not expected here".into(), pos))
}
Sexp::Atom(Atom::F(val), _) => {
Ok(unsafe { std::mem::transmute(val) })
}
Sexp::Atom(Atom::S(s), pos) => { Sexp::Atom(Atom::S(s), pos) => {
let pstate = pcx.state.borrow(); let pstate = pcx.state.borrow();
if let Some(val) = pstate.constants.get(&s) { if let Some(val) = pstate.constants.get(&s) {
return Ok(*val); return Ok(*val);
} }
Ok(unsafe { std::mem::transmute(parse_i64(&s, &pos)?) }) Err(CrsnError::Parse(format!("unknown constant: {}", s).into(), pos))
} }
other => { Sexp::List(_, pos) => {
Err(CrsnError::Parse(format!("bad value format: {:?}", other).into(), other.pos().clone())) Err(CrsnError::Parse("expected a value".into(), pos))
} }
} }
} }
@ -204,15 +201,6 @@ pub fn parse_u64(literal: &str, pos: &SourcePosition) -> Result<u64, CrsnError>
} }
} }
pub fn parse_i64(literal: &str, pos: &SourcePosition) -> Result<i64, CrsnError> {
// trace!("parse i64 from {}", literal);
if let Some(_value) = literal.strip_prefix("-") {
Ok(-1 * i64::try_from(parse_u64(literal, pos)?).err_pos(pos)?)
} else {
Ok(i64::try_from(parse_u64(literal, pos)?).err_pos(pos)?)
}
}
pub fn parse_rd(tok: Sexp, pcx: &ParserContext) -> Result<Rd, CrsnError> { pub fn parse_rd(tok: Sexp, pcx: &ParserContext) -> Result<Rd, CrsnError> {
let pos = tok.pos().clone(); let pos = tok.pos().clone();
Ok(Rd::new(RdData::try_from(parse_data_disp(tok, pcx)?).err_pos(&pos)?)) Ok(Rd::new(RdData::try_from(parse_data_disp(tok, pcx)?).err_pos(&pos)?))

@ -36,10 +36,20 @@ pub fn expect_string_atom(expr: Sexp) -> Result<(String, SourcePosition), CrsnEr
} }
} }
// pub fn expect_int_atom(expr: Option<Sexp>) -> Result<i64, Error> { pub fn expect_quoted_string_atom(expr: Sexp) -> Result<(String, SourcePosition), CrsnError> {
// match expect_atom(expr) { match expect_atom(expr) {
// Ok(Atom::I(v)) => Ok(v), Ok((Atom::QS(s), pos)) => Ok((s, pos)),
// Ok(atom) => Err(Error::ParseIn("Expected int atom".into(), Sexp::Atom(atom))), Ok((_, pos)) => Err(CrsnError::Parse("Expected quoted string atom".into(), pos)),
// Err(e) => Err(e), Err(e) => Err(e),
// } }
// } }
/// Quoted or simple string
pub fn expect_any_string_atom(expr: Sexp) -> Result<(String, SourcePosition), CrsnError> {
match expect_atom(expr) {
Ok((Atom::S(s), pos)) => Ok((s, pos)),
Ok((Atom::QS(s), pos)) => Ok((s, pos)),
Ok((_, pos)) => Err(CrsnError::Parse("Expected quoted string atom".into(), pos)),
Err(e) => Err(e),
}
}

@ -53,7 +53,7 @@ pub enum BuiltinOp {
Fault(Option<DebugMsg>), Fault(Option<DebugMsg>),
/// Deallocate an extension object. /// Deallocate an extension object.
/// The object is released and the handle becomes invalid. /// The object is released and the handle becomes invalid.
Drop(RdObj), Delete(RdObj),
/// Copy value /// Copy value
Move { dst: Wr, src: Rd }, Move { dst: Wr, src: Rd },
/// Store runtime status to a register /// Store runtime status to a register

@ -120,7 +120,7 @@ impl OpTrait for BuiltinOp {
BuiltinOp::Sleep { micros } => { BuiltinOp::Sleep { micros } => {
std::thread::sleep(Duration::from_micros(state.read(*micros)?)) std::thread::sleep(Duration::from_micros(state.read(*micros)?))
} }
BuiltinOp::Drop(obj) => { BuiltinOp::Delete(obj) => {
let x = state.read(Rd::new(RdData::Register(obj.reg())))?; let x = state.read(Rd::new(RdData::Register(obj.reg())))?;
trace!("Drop object: {:#x}", x); trace!("Drop object: {:#x}", x);

@ -6,7 +6,7 @@ use crate::asm::error::CrsnError;
use crate::asm::instr::op::OpKind; use crate::asm::instr::op::OpKind;
use crate::asm::parse::arg_parser::TokenParser; use crate::asm::parse::arg_parser::TokenParser;
use crate::asm::parse::parse_data::{parse_constant_name, parse_label, parse_label_str, parse_rd, parse_reg_alias, parse_value}; use crate::asm::parse::parse_data::{parse_constant_name, parse_label, parse_label_str, parse_rd, parse_reg_alias, parse_value};
use crate::asm::parse::sexp_expect::expect_string_atom; use crate::asm::parse::sexp_expect::{expect_any_string_atom};
use crate::asm::patches::ErrWithPos; use crate::asm::patches::ErrWithPos;
use crate::builtin::defs::{Barrier, BuiltinOp}; use crate::builtin::defs::{Barrier, BuiltinOp};
use crate::module::ParseRes; use crate::module::ParseRes;
@ -135,7 +135,7 @@ pub(crate) fn parse_op<'a>(op_pos: &SourcePosition, keyword: &str, mut args: Tok
kind: Barrier::Standalone, kind: Barrier::Standalone,
msg: match args.next() { msg: match args.next() {
None => None, None => None,
Some(s) => Some(expect_string_atom(s)?.0.into()), Some(s) => Some(expect_any_string_atom(s)?.0.into()),
}, },
} }
} }
@ -157,7 +157,7 @@ pub(crate) fn parse_op<'a>(op_pos: &SourcePosition, keyword: &str, mut args: Tok
"fault" => { "fault" => {
BuiltinOp::Fault(match args.next() { BuiltinOp::Fault(match args.next() {
None => None, None => None,
Some(s) => Some(expect_string_atom(s)?.0.into()), Some(s) => Some(expect_any_string_atom(s)?.0.into()),
}) })
} }
@ -180,8 +180,8 @@ pub(crate) fn parse_op<'a>(op_pos: &SourcePosition, keyword: &str, mut args: Tok
} }
} }
"drop" => { "del" => {
BuiltinOp::Drop(args.next_rdobj()?) BuiltinOp::Delete(args.next_rdobj()?)
} }
"far" => { "far" => {
@ -277,7 +277,7 @@ pub(crate) fn to_sexp(op: &BuiltinOp) -> Sexp {
sexp::list(&[A("fault")]) sexp::list(&[A("fault")])
} }
} }
BuiltinOp::Drop(obj) => sexp::list(&[A("drop"), A(obj)]), BuiltinOp::Delete(obj) => sexp::list(&[A("del"), A(obj)]),
BuiltinOp::Move { dst, src } => sexp::list(&[A("ld"), A(dst), A(src)]), BuiltinOp::Move { dst, src } => sexp::list(&[A("ld"), A(dst), A(src)]),
BuiltinOp::StoreStatus { dst } => sexp::list(&[A("sst"), A(dst)]), BuiltinOp::StoreStatus { dst } => sexp::list(&[A("sst"), A(dst)]),
BuiltinOp::LoadStatus { src } => sexp::list(&[A("sld"), A(src)]) BuiltinOp::LoadStatus { src } => sexp::list(&[A("sld"), A(src)])
@ -303,6 +303,12 @@ mod test {
("(nop)", "(nop)"), ("(nop)", "(nop)"),
("(halt)", "(halt)"), ("(halt)", "(halt)"),
("(sleep 1000)", "(sleep 1000)"), ("(sleep 1000)", "(sleep 1000)"),
("(sleep 1_0_0_0)", "(sleep 1000)"),
("(sleep ' ')", "(sleep 32)"),
("(sleep '\\n')", "(sleep 10)"),
("(sleep 0b111)", "(sleep 7)"),
("(sleep 0xab_cd)", "(sleep 43981)"),
("(sleep #ab_cd)", "(sleep 43981)"),
("(:x)", "(:x)"), ("(:x)", "(:x)"),
("(j :x)", "(j :x)"), ("(j :x)", "(j :x)"),
("(:#7)", "(:#7)"), ("(:#7)", "(:#7)"),
@ -345,8 +351,8 @@ mod test {
("(sst r0)", "(sst r0)"), ("(sst r0)", "(sst r0)"),
("(sld r0)", "(sld r0)"), ("(sld r0)", "(sld r0)"),
("(far :label)", "(far :label)"), ("(far :label)", "(far :label)"),
("(drop @r5)", "(drop @r5)"), ("(del @r5)", "(del @r5)"),
("(sym cat r0)(drop @cat)", "(drop @r0)"), ("(sym cat r0)(del @cat)", "(del @r0)"),
]; ];
let parser = BuiltinOps::new(); let parser = BuiltinOps::new();

@ -1,6 +1,7 @@
#[macro_use] #[macro_use]
extern crate log; extern crate log;
// re-export our customized version of sexp
pub use sexp; pub use sexp;
pub mod asm; pub mod asm;

@ -11,6 +11,11 @@ mod option_ext;
pub fn A(s: impl Display) -> Sexp { pub fn A(s: impl Display) -> Sexp {
let s = s.to_string(); let s = s.to_string();
let x: Result<u64, _> = FromStr::from_str(&s);
if let Ok(x) = x {
return Sexp::Atom(Atom::U(x), Default::default());
}
let x: Result<i64, _> = FromStr::from_str(&s); let x: Result<i64, _> = FromStr::from_str(&s);
if let Ok(x) = x { if let Ok(x) = x {
return Sexp::Atom(Atom::I(x), Default::default()); return Sexp::Atom(Atom::I(x), Default::default());
@ -21,5 +26,9 @@ pub fn A(s: impl Display) -> Sexp {
return Sexp::Atom(Atom::F(y), Default::default()); return Sexp::Atom(Atom::F(y), Default::default());
} }
if s.contains(|c: char| " \t\"\\\n\t\r".contains(c)) {
Sexp::Atom(Atom::QS(s), Default::default())
} else {
Sexp::Atom(Atom::S(s), Default::default()) Sexp::Atom(Atom::S(s), Default::default())
} }
}

@ -4,10 +4,10 @@ use crsn::asm::instr::op::OpKind;
use crsn::asm::parse::arg_parser::TokenParser; use crsn::asm::parse::arg_parser::TokenParser;
use crsn::module::{CrsnExtension, ParseRes, CrsnUniq}; use crsn::module::{CrsnExtension, ParseRes, CrsnUniq};
use crsn::runtime::fault::Fault; use crsn::runtime::fault::Fault;
use crsn::runtime::run_thread::{RunState, ThreadInfo}; use crsn::runtime::run_thread::{RunState};
use crsn::sexp::SourcePosition; use crsn::sexp::SourcePosition;
use crsn::asm::data::Mask; use crsn::asm::data::Mask;
use std::io::{Read, stdin, stdout, Write}; use std::io::{Write};
use std::convert::TryFrom; use std::convert::TryFrom;
use crsn::asm::instr::Cond; use crsn::asm::instr::Cond;
use console::Term; use console::Term;
@ -61,7 +61,7 @@ impl CrsnExtension for StdioOps {
"stdio" "stdio"
} }
fn parse_op<'a>(&self, pos: &SourcePosition, keyword: &str, args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> { fn parse_op<'a>(&self, _pos: &SourcePosition, _keyword: &str, args: TokenParser<'a>) -> Result<ParseRes<'a, OpKind>, CrsnError> {
Ok(ParseRes::Unknown(args)) Ok(ParseRes::Unknown(args))
} }

@ -32,5 +32,5 @@
(rpop r1 @r0) (rpop r1 @r0)
(cmp r1 1000 (ne? (fault))) (cmp r1 1000 (ne? (fault)))
(drop @r0) (del @r0)
) )

@ -1,8 +1,10 @@
( (
; we don't have strings yet 👌 ; we don't have strings yet 👌
(ld @stdout 'H') (ld @stdout 'e') (ld @stdout 'l') (ld @stdout 'l') (ld @stdout 'o') (ld @stdout 'P') (ld @stdout 'r') (ld @stdout 'e') (ld @stdout 's') (ld @stdout 's') (ld @stdout ' ')
(ld @stdout 32) (ld @stdout 'c') (ld @stdout 'r') (ld @stdout 's') (ld @stdout 'n') (ld @stdout 'q') (ld @stdout ' ')
(ld @stdout '…') (ld @stdout 32) (ld @stdout 't') (ld @stdout 'o') (ld @stdout ' ')
(ld @stdout 'q') (ld @stdout 'u') (ld @stdout 'i') (ld @stdout 't')
(ld @stdout '…') (ld @stdout ' ')
(:loop) (:loop)
(ld r0 @stdin) (ld r0 @stdin)
@ -15,7 +17,7 @@
; uppercase ASCII ; uppercase ASCII
(cmp r0 'a' (<? (j :badchar))) (cmp r0 'a' (<? (j :badchar)))
(cmp r0 'z' (>? (j :badchar))) (cmp r0 'z' (>? (j :badchar)))
(sub r0 32) (sub r0 ' ')
(ld @stdout r0) (ld @stdout r0)
(j :loop) (j :loop)

@ -33,7 +33,7 @@ struct Config {
#[serde(skip)] #[serde(skip)]
program_file: String, program_file: String,
#[serde(skip)] #[serde(skip)]
asm_only: bool, assemble_only: bool,
#[serde(with = "serde_duration_millis")] #[serde(with = "serde_duration_millis")]
cycle_time: Duration, cycle_time: Duration,
} }
@ -42,11 +42,11 @@ impl Default for Config {
fn default() -> Self { fn default() -> Self {
Self { Self {
log: LogConfig { log: LogConfig {
level: "info".to_string(), level: "warn".to_string(),
modules: Default::default(), modules: Default::default(),
}, },
program_file: "".to_string(), program_file: "".to_string(),
asm_only: false, assemble_only: false,
cycle_time: Duration::default(), cycle_time: Duration::default(),
} }
} }
@ -63,6 +63,14 @@ impl AppConfig for Config {
Some(&self.log.modules) Some(&self.log.modules)
} }
fn pre_log_println(_message: String) {
// shut up
}
fn print_banner(_name: &str, _version: &str) {
// No banner
}
/// Add args to later use in the `configure` method. /// Add args to later use in the `configure` method.
fn add_args<'a: 'b, 'b>(clap: clap::App<'a, 'b>) -> clap::App<'a, 'b> { fn add_args<'a: 'b, 'b>(clap: clap::App<'a, 'b>) -> clap::App<'a, 'b> {
// Default impl // Default impl
@ -106,7 +114,7 @@ impl AppConfig for Config {
fn configure(mut self, clap: &ArgMatches) -> anyhow::Result<Self> { fn configure(mut self, clap: &ArgMatches) -> anyhow::Result<Self> {
self.program_file = clap.value_of("input").unwrap().to_string(); self.program_file = clap.value_of("input").unwrap().to_string();
self.asm_only = clap.is_present("asm-only"); self.assemble_only = clap.is_present("asm-only");
if let Some(c) = clap.value_of("cycle") { if let Some(c) = clap.value_of("cycle") {
self.cycle_time = Duration::from_millis(c.parse().unwrap()); self.cycle_time = Duration::from_millis(c.parse().unwrap());
} }
@ -118,7 +126,7 @@ impl AppConfig for Config {
fn main() -> anyhow::Result<()> { fn main() -> anyhow::Result<()> {
let config = Config::init("crsn", "crsn.json5", env!("CARGO_PKG_VERSION"))?; let config = Config::init("crsn", "crsn.json5", env!("CARGO_PKG_VERSION"))?;
info!("Loading {}", config.program_file); debug!("Loading {}", config.program_file);
let source = read_file::read_file(&config.program_file)?; let source = read_file::read_file(&config.program_file)?;
@ -131,7 +139,7 @@ fn main() -> anyhow::Result<()> {
StdioOps::new(), StdioOps::new(),
])?; ])?;
if config.asm_only { if config.assemble_only {
for (n, op) in parsed.ops.iter().enumerate() { for (n, op) in parsed.ops.iter().enumerate() {
println!("{:04} : {}", n, op.to_sexp()); println!("{:04} : {}", n, op.to_sexp());
} }
@ -144,7 +152,7 @@ fn main() -> anyhow::Result<()> {
trace!("------------------------"); trace!("------------------------");
} }
info!("Start runtime"); debug!("Start runtime");
let args = &[]; let args = &[];
let thread = RunThread::new(ThreadParams { let thread = RunThread::new(ThreadParams {
@ -159,7 +167,7 @@ fn main() -> anyhow::Result<()> {
// run without spawning, so it is on the main thread - required by some extensions // run without spawning, so it is on the main thread - required by some extensions
thread.run(); thread.run();
info!("Runtime shut down."); debug!("Runtime shut down.");
Ok(()) Ok(())
} }

@ -1,9 +0,0 @@
Source-location tracking Sexp
=====
**This is a fork of "sexp", updated to the 2018 edition, where each parsed node tracks its
source file position. This enables better error reporting in subsequent parsing and processing.**
---
Original version by Clark Gaebel: [https://github.com/cgaebel/sexp](https://github.com/cgaebel/sexp).

@ -1,324 +0,0 @@
//! A lightweight, self-contained s-expression parser and data format.
//! Use `parse` to get an s-expression from its string representation, and the
//! `Display` trait to serialize it, potentially by doing `sexp.to_string()`.
#![deny(unsafe_code)]
#[macro_use]
extern crate log;
use std::borrow::Cow;
use std::fmt;
use std::str::{self, FromStr};
use error::{ERes, err, spos};
pub use error::Error;
pub use error::SourcePosition;
#[cfg(test)]
mod test;
mod error;
/// A single data element in an s-expression. Floats are excluded to ensure
/// atoms may be used as keys in ordered and hashed data structures.
///
/// All strings must be valid utf-8.
#[derive(PartialEq, Clone, PartialOrd)]
#[allow(missing_docs)]
pub enum Atom {
S(String),
I(i64),
F(f64),
}
/// An s-expression is either an atom or a list of s-expressions. This is
/// similar to the data format used by lisp.
#[derive(Clone)]
pub enum Sexp {
/// Atom
Atom(Atom, SourcePosition),
/// List of expressions
List(Vec<Sexp>, SourcePosition),
}
impl Sexp {
pub fn pos(&self) -> &SourcePosition {
match self {
Sexp::List(_, pos) | Sexp::Atom(_, pos) => pos
}
}
/// Check fi thsi Sexp is an atom
pub fn is_atom(&self) -> bool {
match self {
Sexp::Atom(_, _) => true,
_ => false,
}
}
/// Check fi thsi Sexp is a list
pub fn is_list(&self) -> bool {
match self {
Sexp::List(_, _) => true,
_ => false,
}
}
}
impl PartialEq for Sexp {
fn eq(&self, other: &Self) -> bool {
match (self, other) {
(Sexp::Atom(a, _), Sexp::Atom(b, _)) => {
a == b
}
(Sexp::List(a, _), Sexp::List(b, _)) => {
a == b
}
_ => false
}
}
}
fn atom_of_string(s: String) -> Atom {
match FromStr::from_str(&s) {
Ok(i) => return Atom::I(i),
Err(_) => {}
};
match FromStr::from_str(&s) {
Ok(f) => return Atom::F(f),
Err(_) => {}
};
Atom::S(s)
}
// returns the char it found, and the new size if you wish to consume that char
fn peek(s: &str, pos: &usize) -> ERes<(char, usize)> {
trace!("peek {}", pos);
if *pos == s.len() { return err("unexpected eof", s, pos); }
if s.is_char_boundary(*pos) {
let ch = s[*pos..].chars().next().unwrap();
let next = *pos + ch.len_utf8();
Ok((ch, next))
} else {
// strings must be composed of valid utf-8 chars.
unreachable!()
}
}
fn expect(s: &str, pos: &mut usize, c: char) -> ERes<()> {
trace!("expect {}", pos);
let (ch, next) = peek(s, pos)?;
*pos = next;
if ch == c { Ok(()) } else { err("unexpected character", s, pos) }
}
fn consume_until_newline(s: &str, pos: &mut usize) -> ERes<()> {
loop {
if *pos == s.len() { return Ok(()); }
let (ch, next) = peek(s, pos)?;
*pos = next;
if ch == '\n' { return Ok(()); }
}
}
// zero or more spaces
fn zspace(s: &str, pos: &mut usize) -> ERes<()> {
trace!("zspace {}", pos);
loop {
if *pos == s.len() { return Ok(()); }
let (ch, next) = peek(s, pos)?;
if ch == ';' { consume_until_newline(s, pos)? } else if ch.is_whitespace() { *pos = next; } else { return Ok(()); }
}
}
fn parse_quoted_atom(s: &str, pos: &mut usize) -> ERes<Atom> {
trace!("parse_quoted_atom {}", pos);
let mut cs: String = String::new();
expect(s, pos, '"')?;
loop {
let (ch, next) = peek(s, pos)?;
if ch == '"' {
*pos = next;
break;
} else if ch == '\\' {
let (postslash, nextnext) = peek(s, &next)?;
if postslash == '"' || postslash == '\\' {
cs.push(postslash);
} else {
cs.push(ch);
cs.push(postslash);
}
*pos = nextnext;
} else {
cs.push(ch);
*pos = next;
}
}
// Do not try i64 conversion, since this atom was explicitly quoted.
Ok(Atom::S(cs))
}
fn parse_unquoted_atom(s: &str, pos: &mut usize) -> ERes<Atom> {
trace!("parse_unquoted_atom {}", pos);
let mut cs: String = String::new();
loop {
if *pos == s.len() { break; }
let (c, next) = peek(s, pos)?;
if c == ';' {
consume_until_newline(s, pos)?;
break;
}
if c.is_whitespace() || c == '(' || c == ')' { break; }
cs.push(c);
*pos = next;
}
Ok(atom_of_string(cs))
}
fn parse_atom(s: &str, pos: &mut usize) -> ERes<Atom> {
trace!("parse_atom {}", pos);
let (ch, _) = peek(s, pos)?;
if ch == '"' { parse_quoted_atom(s, pos) } else { parse_unquoted_atom(s, pos) }
}
fn parse_list(s: &str, pos: &mut usize) -> ERes<Vec<Sexp>> {
trace!("parse_list {}", pos);
zspace(s, pos)?;
expect(s, pos, '(')?;
let mut sexps: Vec<Sexp> = Vec::new();
loop {
zspace(s, pos)?;
let (c, next) = peek(s, pos)?;
if c == ')' {
*pos = next;
break;
}
sexps.push(parse_sexp(s, pos)?);
}
zspace(s, pos)?;
Ok(sexps)
}
fn parse_sexp(s: &str, pos: &mut usize) -> ERes<Sexp> {
trace!("parse_sexp {}", pos);
zspace(s, pos)?;
let (c, _) = peek(s, pos)?;
let r = if c == '(' {
Ok(Sexp::List(parse_list(s, pos)?, spos(s, pos)))
} else {
Ok(Sexp::Atom(parse_atom(s, pos)?, spos(s, pos)))
};
zspace(s, pos)?;
r
}
/// Constructs an atomic s-expression from a string.
pub fn atom_s(s: &str) -> Sexp {
Sexp::Atom(Atom::S(s.to_owned()), Default::default())
}
/// Constructs an atomic s-expression from an int.
pub fn atom_i(i: i64) -> Sexp {
Sexp::Atom(Atom::I(i), Default::default())
}
/// Constructs an atomic s-expression from a float.
pub fn atom_f(f: f64) -> Sexp {
Sexp::Atom(Atom::F(f), Default::default())
}
/// Constructs a list s-expression given a slice of s-expressions.
pub fn list(xs: &[Sexp]) -> Sexp {
Sexp::List(xs.to_owned(), Default::default())
}
/// Reads an s-expression out of a `&str`.
#[inline(never)]
pub fn parse(s: &str) -> Result<Sexp, Box<Error>> {
let mut pos = 0;
let ret = parse_sexp(s, &mut pos)?;
if pos == s.len() { Ok(ret) } else { err("unrecognized post-s-expression data", s, &pos) }
}
// TODO: Pretty print in lisp convention, instead of all on the same line,
// packed as tightly as possible. It's kinda ugly.
fn is_num_string(s: &str) -> bool {
let x: Result<i64, _> = FromStr::from_str(&s);
let y: Result<f64, _> = FromStr::from_str(&s);
x.is_ok() || y.is_ok()
}
fn string_contains_whitespace(s: &str) -> bool {
for c in s.chars() {
if c.is_whitespace() { return true; }
}
false
}
fn quote(s: &str) -> Cow<str> {
if !s.contains("\"")
&& !string_contains_whitespace(s)
&& !is_num_string(s) {
Cow::Borrowed(s)
} else {
let mut r: String = "\"".to_string();
r.push_str(&s.replace("\\", "\\\\").replace("\"", "\\\""));
r.push_str("\"");
Cow::Owned(r)
}
}
impl fmt::Display for Atom {
fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
match *self {
Atom::S(ref s) => write!(f, "{}", quote(s)),
Atom::I(i) => write!(f, "{}", i),
Atom::F(d) => write!(f, "{}", d),
}
}
}
impl fmt::Display for Sexp {
fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
match *self {
Sexp::Atom(ref a, _) => write!(f, "{}", a),
Sexp::List(ref xs, _) => {
write!(f, "(")?;
for (i, x) in xs.iter().enumerate() {
let s = if i == 0 { "" } else { " " };
write!(f, "{}{}", s, x)?;
}
write!(f, ")")
}
}
}
}
impl fmt::Debug for Atom {
fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
write!(f, "{}", self)
}
}
impl fmt::Debug for Sexp {
fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
write!(f, "{}", self)
}
}
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