Add the to_string, write and write_line natives

dust-lang/src/instruction.rs

@@ -584,6 +584,7 @@ impl Instruction {
                 let native_function_name = match native_function {
                     NativeFunction::Panic => "PANIC",
                     NativeFunction::ToString => "TO_STRING",
+                    NativeFunction::Write => "WRITE",
                     NativeFunction::WriteLine => "WRITE_LINE",
                 };
 

dust-lang/src/lexer.rs

@@ -567,8 +567,11 @@ impl<'src> Lexer<'src> {
             "return" => Token::Return,
             "str" => Token::Str,
             "struct" => Token::Struct,
+            "to_string" => Token::ToString,
             "true" => Token::Boolean("true"),
             "while" => Token::While,
+            "write" => Token::Write,
+            "write_line" => Token::WriteLine,
             _ => Token::Identifier(string),
         };
 
@@ -1255,7 +1258,7 @@ mod tests {
         assert_eq!(
             lex(input),
             Ok(vec![
-                (Token::Identifier("write_line"), Span(0, 10)),
+                (Token::WriteLine, Span(0, 10)),
                 (Token::LeftParenthesis, Span(10, 11)),
                 (Token::String("Hello, world!"), Span(11, 26)),
                 (Token::RightParenthesis, Span(26, 27)),

dust-lang/src/native_function.rs

@@ -2,12 +2,14 @@ use serde::{Deserialize, Serialize};
 
 const PANIC: u8 = 0b0000_0000;
 const TO_STRING: u8 = 0b0000_0001;
-const WRITE_LINE: u8 = 0b0000_0010;
+const WRITE: u8 = 0b0000_0010;
+const WRITE_LINE: u8 = 0b0000_0011;
 
 #[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord, Serialize, Deserialize)]
 pub enum NativeFunction {
     Panic = PANIC as isize,
     ToString = TO_STRING as isize,
+    Write = WRITE as isize,
     WriteLine = WRITE_LINE as isize,
 }
 
@@ -16,10 +18,11 @@ impl From<u8> for NativeFunction {
         match byte {
             PANIC => NativeFunction::Panic,
             TO_STRING => NativeFunction::ToString,
+            WRITE => NativeFunction::Write,
             WRITE_LINE => NativeFunction::WriteLine,
             _ => {
                 if cfg!(test) {
-                    panic!("Invalid operation byte: {}", byte)
+                    panic!("Invalid native function byte: {}", byte)
                 } else {
                     NativeFunction::Panic
                 }
@@ -33,6 +36,7 @@ impl From<NativeFunction> for u8 {
         match native_function {
             NativeFunction::Panic => PANIC,
             NativeFunction::ToString => TO_STRING,
+            NativeFunction::Write => WRITE,
             NativeFunction::WriteLine => WRITE_LINE,
         }
     }

dust-lang/src/parser.rs

@@ -1058,7 +1058,18 @@ impl<'src> Parser<'src> {
         Ok(())
     }
 
-    fn parse_panic(&mut self, _: Allowed) -> Result<(), ParseError> {
+    fn parse_native_call(&mut self, _: Allowed) -> Result<(), ParseError> {
+        let native_function = match self.current_token {
+            Token::Panic => NativeFunction::Panic,
+            Token::ToString => NativeFunction::ToString,
+            Token::Write => NativeFunction::Write,
+            Token::WriteLine => NativeFunction::WriteLine,
+            _ => {
+                unreachable!()
+            }
+        };
+        let is_expression = self.current_token.is_expression();
+
         let start = self.current_position.0;
         let start_register = self.next_register();
 
@@ -1086,9 +1097,10 @@ impl<'src> Parser<'src> {
         let end = self.current_position.1;
         let to_register = self.next_register();
         let argument_count = to_register - start_register;
+        self.current_is_expression = is_expression;
 
         self.emit_instruction(
-            Instruction::call_native(to_register, NativeFunction::Panic, argument_count),
+            Instruction::call_native(to_register, native_function, argument_count),
             Span(start, end),
         );
         Ok(())
@@ -1727,7 +1739,7 @@ impl From<&Token<'_>> for ParseRule<'_> {
                 precedence: Precedence::None,
             },
             Token::Panic => ParseRule {
-                prefix: Some(Parser::parse_panic),
+                prefix: Some(Parser::parse_native_call),
                 infix: None,
                 precedence: Precedence::Call,
             },
@@ -1807,11 +1819,26 @@ impl From<&Token<'_>> for ParseRule<'_> {
                 precedence: Precedence::None,
             },
             Token::Struct => todo!(),
+            Token::ToString => ParseRule {
+                prefix: Some(Parser::parse_native_call),
+                infix: None,
+                precedence: Precedence::Call,
+            },
             Token::While => ParseRule {
                 prefix: Some(Parser::parse_while),
                 infix: None,
                 precedence: Precedence::None,
             },
+            Token::Write => ParseRule {
+                prefix: Some(Parser::parse_native_call),
+                infix: None,
+                precedence: Precedence::Call,
+            },
+            Token::WriteLine => ParseRule {
+                prefix: Some(Parser::parse_native_call),
+                infix: None,
+                precedence: Precedence::Call,
+            },
         }
     }
 }

dust-lang/src/token.rs

@@ -3,13 +3,28 @@ use std::fmt::{self, Display, Formatter};
 
 use serde::{Deserialize, Serialize};
 
-/// Source code token.
+macro_rules! define_tokens {
+    ($($variant:ident $(($data_type:ty))?),+ $(,)?) => {
         #[derive(Debug, Clone, Copy, Eq, PartialEq, PartialOrd, Ord, Default, Serialize, Deserialize)]
         pub enum Token<'src> {
-    // End of file
             #[default]
             Eof,
+            $(
+                $variant $(($data_type))?,
+            )*
+        }
 
+        #[derive(Debug, PartialEq, Clone)]
+        pub enum TokenKind {
+            Eof,
+            $(
+                $variant,
+            )*
+        }
+    };
+}
+
+define_tokens! {
     // Hard-coded values
     Boolean(&'src str),
     Byte(&'src str),
@@ -36,7 +51,11 @@ pub enum Token<'src> {
     Return,
     Str,
     Struct,
+    ToString,
     While,
+    Write,
+
+    WriteLine,
 
     // Symbols
     ArrowThin,
@@ -100,7 +119,10 @@ impl<'src> Token<'src> {
             Token::Mut => 3,
             Token::Str => 3,
             Token::Struct => 6,
+            Token::ToString => 8,
             Token::While => 5,
+            Token::Write => 5,
+            Token::WriteLine => 10,
             Token::BangEqual => 2,
             Token::Bang => 1,
             Token::Colon => 1,
@@ -162,6 +184,7 @@ impl<'src> Token<'src> {
             Token::Mut => "mut",
             Token::Str => "str",
             Token::Struct => "struct",
+            Token::ToString => "to_string",
             Token::While => "while",
             Token::BangEqual => "!=",
             Token::Bang => "!",
@@ -196,6 +219,8 @@ impl<'src> Token<'src> {
             Token::SlashEqual => "/=",
             Token::Star => "*",
             Token::StarEqual => "*=",
+            Token::Write => "write",
+            Token::WriteLine => "write_line",
         }
     }
 
@@ -257,7 +282,10 @@ impl<'src> Token<'src> {
             Token::String(text) => TokenOwned::String(text.to_string()),
             Token::Str => TokenOwned::Str,
             Token::Struct => TokenOwned::Struct,
+            Token::ToString => TokenOwned::ToString,
             Token::While => TokenOwned::While,
+            Token::Write => TokenOwned::Write,
+            Token::WriteLine => TokenOwned::WriteLine,
         }
     }
 
@@ -318,8 +346,11 @@ impl<'src> Token<'src> {
             Token::SlashEqual => TokenKind::SlashEqual,
             Token::Str => TokenKind::Str,
             Token::String(_) => TokenKind::String,
+            Token::ToString => TokenKind::ToString,
             Token::Struct => TokenKind::Struct,
             Token::While => TokenKind::While,
+            Token::Write => TokenKind::Write,
+            Token::WriteLine => TokenKind::WriteLine,
         }
     }
 
@@ -356,13 +387,13 @@ impl<'src> Token<'src> {
                 | Token::MinusEqual
                 | Token::Percent
                 | Token::PercentEqual
-                | Token::Panic
                 | Token::Plus
                 | Token::PlusEqual
                 | Token::Slash
                 | Token::SlashEqual
                 | Token::Star
                 | Token::StarEqual
+                | Token::ToString
         )
     }
 }
@@ -425,8 +456,11 @@ impl<'src> Display for Token<'src> {
             Token::StarEqual => write!(f, "*="),
             Token::Str => write!(f, "str"),
             Token::String(value) => write!(f, "{value}"),
+            Token::ToString => write!(f, "to_string"),
             Token::Struct => write!(f, "struct"),
             Token::While => write!(f, "while"),
+            Token::Write => write!(f, "write"),
+            Token::WriteLine => write!(f, "write_line"),
         }
     }
 }
@@ -464,7 +498,10 @@ pub enum TokenOwned {
     Panic,
     Return,
     Str,
+    ToString,
     While,
+    Write,
+    WriteLine,
 
     // Symbols
     ArrowThin,
@@ -561,80 +598,14 @@ impl Display for TokenOwned {
             TokenOwned::Str => Token::Str.fmt(f),
             TokenOwned::String(string) => Token::String(string).fmt(f),
             TokenOwned::Struct => Token::Struct.fmt(f),
+            TokenOwned::ToString => Token::ToString.fmt(f),
             TokenOwned::While => Token::While.fmt(f),
+            TokenOwned::Write => Token::Write.fmt(f),
+            TokenOwned::WriteLine => Token::WriteLine.fmt(f),
         }
     }
 }
 
-/// Token representation that holds no data.
-#[derive(Debug, PartialEq, Clone)]
-pub enum TokenKind {
-    Eof,
-
-    Identifier,
-
-    // Hard-coded values
-    Boolean,
-    Byte,
-    Character,
-    Float,
-    Integer,
-    String,
-
-    // Keywords
-    Async,
-    Bool,
-    Break,
-    Else,
-    FloatKeyword,
-    Fn,
-    If,
-    Int,
-    Let,
-    Loop,
-    Map,
-    Panic,
-    Return,
-    Str,
-    While,
-
-    // Symbols
-    ArrowThin,
-    BangEqual,
-    Bang,
-    Colon,
-    Comma,
-    Dot,
-    DoubleAmpersand,
-    DoubleDot,
-    DoubleEqual,
-    DoublePipe,
-    Equal,
-    Greater,
-    GreaterEqual,
-    LeftCurlyBrace,
-    LeftParenthesis,
-    LeftSquareBrace,
-    Less,
-    LessEqual,
-    Minus,
-    MinusEqual,
-    Mut,
-    Percent,
-    PercentEqual,
-    Plus,
-    PlusEqual,
-    RightCurlyBrace,
-    RightParenthesis,
-    RightSquareBrace,
-    Semicolon,
-    Star,
-    StarEqual,
-    Struct,
-    Slash,
-    SlashEqual,
-}
-
 impl Display for TokenKind {
     fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         match self {
@@ -694,7 +665,10 @@ impl Display for TokenKind {
             TokenKind::SlashEqual => Token::SlashEqual.fmt(f),
             TokenKind::String => write!(f, "string value"),
             TokenKind::Struct => Token::Struct.fmt(f),
+            TokenKind::ToString => Token::ToString.fmt(f),
             TokenKind::While => Token::While.fmt(f),
+            TokenKind::Write => Token::Write.fmt(f),
+            TokenKind::WriteLine => Token::WriteLine.fmt(f),
         }
     }
 }

dust-lang/src/vm.rs

@@ -1,4 +1,8 @@
-use std::{cmp::Ordering, mem::replace};
+use std::{
+    cmp::Ordering,
+    io::{self, stdout, Write},
+    mem::replace,
+};
 
 use crate::{
     parse, value::Primitive, AnnotatedError, Chunk, ChunkError, DustError, FunctionType,
@@ -423,7 +427,56 @@ impl Vm {
 
                             Some(Value::Primitive(Primitive::String(string)))
                         }
-                        NativeFunction::WriteLine => todo!(),
+                        NativeFunction::Write => {
+                            let mut stdout = stdout();
+
+                            for argument_index in 0..argument_count {
+                                if argument_index != 0 {
+                                    stdout.write(b" ").map_err(|io_error| VmError::Io {
+                                        error: io_error.kind(),
+                                        position,
+                                    })?;
+                                }
+
+                                let argument = self.get(argument_index, position)?;
+
+                                write!(stdout, "{}", argument).map_err(|io_error| VmError::Io {
+                                    error: io_error.kind(),
+                                    position,
+                                })?;
+                            }
+
+                            None
+                        }
+                        NativeFunction::WriteLine => {
+                            let mut stdout = stdout();
+
+                            for argument_index in 0..argument_count {
+                                if argument_index != 0 {
+                                    stdout.write(b" ").map_err(|io_error| VmError::Io {
+                                        error: io_error.kind(),
+                                        position,
+                                    })?;
+                                }
+
+                                let argument_string =
+                                    self.get(argument_index, position)?.to_string();
+
+                                stdout.write_all(argument_string.as_bytes()).map_err(
+                                    |io_error| VmError::Io {
+                                        error: io_error.kind(),
+                                        position,
+                                    },
+                                )?;
+                            }
+
+                            stdout.write(b"\n").map_err(|io_error| VmError::Io {
+                                error: io_error.kind(),
+                                position,
+                            })?;
+
+                            None
+                        }
                     };
 
                     if let Some(value) = return_value {
@@ -695,6 +748,10 @@ pub enum VmError {
 
     // Wrappers for foreign errors
     Chunk(ChunkError),
+    Io {
+        error: io::ErrorKind,
+        position: Span,
+    },
     Value {
         error: ValueError,
         position: Span,
@@ -725,6 +782,7 @@ impl AnnotatedError for VmError {
             Self::StackUnderflow { .. } => "Stack underflow",
             Self::UndefinedVariable { .. } => "Undefined variable",
             Self::Chunk(error) => error.description(),
+            Self::Io { .. } => "I/O error",
             Self::Value { .. } => "Value error",
         }
     }
@@ -741,6 +799,7 @@ impl AnnotatedError for VmError {
                 Some(format!("{identifier} is not in scope"))
             }
             Self::Chunk(error) => error.details(),
+            Self::Io { error, .. } => Some(error.to_string()),
             Self::Value { error, .. } => Some(error.to_string()),
             _ => None,
         }
@@ -759,6 +818,7 @@ impl AnnotatedError for VmError {
             Self::StackOverflow { position } => *position,
             Self::UndefinedVariable { position, .. } => *position,
             Self::Chunk(error) => error.position(),
+            Self::Io { position, .. } => *position,
             Self::Value { position, .. } => *position,
         }
     }

dust-lang/tests/native_functions.rs

@@ -15,7 +15,6 @@ fn panic() {
                     Instruction::call_native(2, NativeFunction::Panic, 2),
                     Span(0, 27)
                 ),
-                (Instruction::r#return(true), Span(27, 27))
             ],
             vec![Value::string("Goodbye world!"), Value::integer(42)],
             vec![]
@@ -33,3 +32,27 @@ fn panic() {
         })
     )
 }
+
+#[test]
+fn to_string() {
+    let source = "to_string(42)";
+
+    assert_eq!(
+        parse(source),
+        Ok(Chunk::with_data(
+            None,
+            vec![
+                (Instruction::load_constant(0, 0, false), Span(10, 12)),
+                (
+                    Instruction::call_native(1, NativeFunction::ToString, 1),
+                    Span(0, 13)
+                ),
+                (Instruction::r#return(true), Span(13, 13))
+            ],
+            vec![Value::integer(42)],
+            vec![]
+        )),
+    );
+
+    assert_eq!(run(source), Ok(Some(Value::string("42"))))
+}