Big refactoring, invalid assembly is now unrepresentable assembly

vasm/src/ast.rs

@@ -1,12 +1,10 @@
-use std::convert::TryFrom;
 use std::str::FromStr;
 
 use pest::iterators::Pair;
 
 use vcore::opcodes::Opcode;
 
-use crate::parse_error::ParseError;
+use crate::vasm_parser::Rule;
-use crate::vasm_parser::{Rule, VASMParser};
 
 /// A non-opcode directive to the assembler
 #[derive(Debug, PartialEq, Copy, Clone)]
@@ -28,26 +26,6 @@ impl From<Pair<'_, Rule>> for Directive {
     }
 }
 
-/// Either an opcode or a directive; something that lives in the
-/// instruction column of a line
-#[derive(Debug, PartialEq, Copy, Clone)]
-pub enum Instruction {
-    Directive(Directive),
-    Opcode(Opcode),
-}
-
-impl<'a> TryFrom<Pair<'a, Rule>> for Instruction {
-    type Error = ParseError<'a>;
-
-    fn try_from(pair: Pair<'a, Rule>) -> Result<Self, Self::Error> {
-        match pair.as_rule() {
-            Rule::opcode => Ok(Instruction::Opcode(Opcode::try_from(pair.as_str())?)),
-            Rule::directive => Ok(Instruction::Directive(Directive::from(pair))),
-            _ => Err(ParseError::InvalidInstruction(pair.as_str())),
-        }
-    }
-}
-
 /// One of the five arithmetical operators
 #[derive(Debug, PartialEq, Copy, Clone)]
 pub enum Operator {
@@ -96,12 +74,12 @@ impl<'a> Node<'a> {
         for inner in pair.into_inner() {
             let string_inner = inner.as_str();
             match string_inner {
-                "\\t" => string.push_str("\t"),
+                "\\t" => string.push('\t'),
-                "\\r" => string.push_str("\r"),
+                "\\r" => string.push('\r'),
-                "\\n" => string.push_str("\n"),
+                "\\n" => string.push('\n'),
-                "\\0" => string.push_str("\0"),
+                "\\0" => string.push('\0'),
-                "\\\\" => string.push_str("\\"),
+                "\\\\" => string.push('\\'),
-                "\\\"" => string.push_str("\""),
+                "\\\"" => string.push('\"'),
                 _ => string.push_str(string_inner),
             }
         }
@@ -125,102 +103,55 @@ impl<'a> Node<'a> {
     }
 }
 
-impl<'a> TryFrom<Pair<'a, Rule>> for Node<'a> {
+impl<'a> From<Pair<'a, Rule>> for Node<'a> {
-    type Error = ParseError<'a>;
+    /// Parse a given pair into the `Node` it represents. The result of this is a
-
-    /// Attempt to parse a given pair into the `Node` it represents. The result of this is a
     /// `Node` that might contain a borrow of part of the original code, but which in no way
     /// depends on the original pair's object model.
-    fn try_from(pair: Pair<'a, Rule>) -> Result<Self, Self::Error> {
+    fn from(pair: Pair<'a, Rule>) -> Self {
         match pair.as_rule() {
             Rule::expr | Rule::term => {
                 let mut iter = pair.into_inner();
-                let first = Node::try_from(iter.next().unwrap())?;
+                let first = Node::from(iter.next().unwrap());
                 let mut rest = Vec::<(Operator, Node)>::new();
 
                 while let Some(operator) = iter.next() {
                     let rhs = iter.next().unwrap();
                     let op = Operator::from(operator);
-                    let node = Node::try_from(rhs)?;
+                    let node = Node::from(rhs);
                     rest.push((op, node));
                 }
-                Ok(Node::Expr(Box::from(first), rest))
+                Node::Expr(Box::from(first), rest)
             }
-            Rule::fact | Rule::number => Ok(Node::try_from(pair.into_inner().next().unwrap())?),
+            Rule::fact | Rule::number => Node::from(pair.into_inner().next().unwrap()),
             Rule::dec_number | Rule::dec_zero | Rule::neg_number => {
-                Ok(Node::Number(i32::from_str(pair.as_str()).unwrap()))
+                Node::Number(i32::from_str(pair.as_str()).unwrap())
             }
-            Rule::hex_number => Ok(Node::Number(
+            Rule::hex_number => {
-                i32::from_str_radix(pair.as_str().get(2..).unwrap(), 16).unwrap(),
+                Node::Number(i32::from_str_radix(pair.as_str().get(2..).unwrap(), 16).unwrap())
-            )),
+            }
-            Rule::bin_number => Ok(Node::Number(
+            Rule::bin_number => {
-                i32::from_str_radix(pair.as_str().get(2..).unwrap(), 2).unwrap(),
+                Node::Number(i32::from_str_radix(pair.as_str().get(2..).unwrap(), 2).unwrap())
-            )),
+            }
-            Rule::oct_number => Ok(Node::Number(
+            Rule::oct_number => {
-                i32::from_str_radix(pair.as_str().get(2..).unwrap(), 8).unwrap(),
+                Node::Number(i32::from_str_radix(pair.as_str().get(2..).unwrap(), 8).unwrap())
-            )),
+            }
-            Rule::string => Ok(Node::string(pair)),
+            Rule::string => Node::string(pair),
-            Rule::label => Ok(Node::Label(pair.as_str())),
+            Rule::label => Node::Label(pair.as_str()),
-            Rule::relative_label => Ok(Node::RelativeLabel(pair.as_str().get(1..).unwrap())),
+            Rule::relative_label => Node::RelativeLabel(pair.as_str().get(1..).unwrap()),
-            Rule::absolute_line_offset | Rule::relative_line_offset => Ok(Node::line_offset(pair)),
+            Rule::absolute_line_offset | Rule::relative_line_offset => Node::line_offset(pair),
-            _ => todo!(),
+            _ => unreachable!(),
         }
     }
 }
 
 #[derive(Debug, PartialEq, Clone)]
-pub struct VASMLine<'a> {
+pub struct Label<'a>(pub &'a str);
-    label: Option<&'a str>,
+
-    instruction: Option<Instruction>,
+#[derive(Debug, PartialEq, Clone)]
-    argument: Option<Node<'a>>,
+pub enum VASMLine<'a> {
-}
+    Instruction(Option<Label<'a>>, Opcode, Option<Node<'a>>),
-
+    Db(Option<Label<'a>>, Node<'a>),
-impl<'a> VASMLine<'a> {
+    Org(Option<Label<'a>>, Node<'a>),
-    pub fn blank() -> VASMLine<'a> {
+    Equ(Label<'a>, Node<'a>),
-        VASMLine {
+    LabelDef(Label<'a>),
-            label: None,
-            instruction: None,
-            argument: None,
-        }
-    }
-
-    pub fn with_instruction(self, instruction: Instruction) -> VASMLine<'a> {
-        VASMLine {
-            label: self.label,
-            instruction: Some(instruction),
-            argument: self.argument,
-        }
-    }
-
-    pub fn with_opcode(self, opcode: Opcode) -> VASMLine<'a> {
-        VASMLine {
-            label: self.label,
-            instruction: Some(Instruction::Opcode(opcode)),
-            argument: self.argument,
-        }
-    }
-
-    pub fn with_directive(self, directive: Directive) -> VASMLine<'a> {
-        VASMLine {
-            label: self.label,
-            instruction: Some(Instruction::Directive(directive)),
-            argument: self.argument,
-        }
-    }
-
-    pub fn with_label(self, label: &'a str) -> Self {
-        VASMLine {
-            label: Some(label),
-            instruction: self.instruction,
-            argument: self.argument,
-        }
-    }
-
-    pub fn with_argument(self, argument: Node<'a>) -> Self {
-        VASMLine {
-            label: self.label,
-            instruction: self.instruction,
-            argument: Some(argument),
-        }
-    }
 }

vasm/src/lib.rs

@@ -0,0 +1,7 @@
+extern crate pest;
+#[macro_use]
+extern crate pest_derive;
+
+pub mod ast;
+pub mod parse_error;
+pub mod vasm_parser;

vasm/src/main.rs

@@ -1,11 +0,0 @@
-extern crate pest;
-#[macro_use]
-extern crate pest_derive;
-
-mod vasm_parser;
-mod parse_error;
-mod ast;
-
-fn main() {
-    println!("Hello, world!");
-}

vasm/src/parse_error.rs

@@ -17,10 +17,9 @@ impl<'a> From<InvalidMnemonic<'a>> for ParseError<'a> {
 impl<'a> Display for ParseError<'a> {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         use ParseError::*;
-        use crate::parse_error::ParseError::LineParseFailure;
         match self {
             LineParseFailure => write!(f, "Failed to parse line"),
-            InvalidInstruction(p) => write!(f, "Cannot parse {} as instruction", p)
+            InvalidInstruction(p) => write!(f, "Cannot parse {} as instruction", p),
         }
     }
 }

vasm/src/vasm.pest

@@ -24,6 +24,7 @@ number = { dec_number | hex_number | bin_number | oct_number | dec_zero | neg_nu
 // a digit:
 label_char = { ASCII_ALPHA_LOWER | ASCII_ALPHA_UPPER | "_" }
 label = @{ label_char ~ (label_char | ASCII_DIGIT | "$")* }
+label_def = { label ~ ":" }
 
 // To make relative jumps easier, we'll also allow an '@' at the start of a label, and interpret
 // that as meaning "relative to the first byte of this instruction:"
@@ -35,13 +36,7 @@ absolute_line_offset = { "$" ~ sign ~ dec_number }
 // And the relative form of that, @+nnn and @-nnn:
 relative_line_offset = { "@" ~ sign ~ dec_number }
 
-opcode = @{ ASCII_ALPHA_LOWER+ } // TODO: replace with actual list
+opcode = @{ ASCII_ALPHA_LOWER+ }
-
-// The assembler will support some directives:
-// - .org to set the current address
-// - .db to embed some data
-// - .equ to define some constants
-directive = { ".org" | ".db" | ".equ" }
 
 // The .equ directive isn't much use without the ability to have expressions based on
 // symbols, so, a quick arithmetic expression parser:
@@ -61,14 +56,16 @@ string = ${ "\"" ~ string_inner* ~ "\"" }
 
 // Parsing a line
 // Normally an assembly line will be a sequence of "label, opcode, argument, comment."
-// However, most of these elements are optional. An opcode is only required if an
+// However, only some combinations of these are valid. Comments are already handled by
-// argument exists. Comments are already handled by the COMMENT pattern
+// the COMMENT pattern.
-
+// Also, a line might be an actual instruction, or the assembler will support some directives:
-// Some sub-patterns for the portions of a line:
+// - .org to set the current address
-label_group = { label ~ ":" }
+// - .db to embed some data
-
+// - .equ to define some constants
-// An opcode might be an actual opcode, or a directive
+instruction = { label_def? ~ opcode ~ expr? }
-instruction_group = { (opcode | directive) ~ (expr | string)? }
+db_directive = { label_def? ~ ".db" ~ (expr | string) }
+org_directive = { label_def? ~ ".org" ~ expr }
+equ_directive = { label_def ~ ".equ" ~ expr }
 
 // Finally the entire pattern for an assembly line:
-line = { SOI ~ label_group? ~ instruction_group? ~ EOI }
+line = { SOI ~ (db_directive | org_directive | equ_directive | instruction | label_def) ~ EOI }

vasm/src/vasm_parser.rs

@@ -1,18 +1,36 @@
 use std::convert::TryFrom;
-use std::str::FromStr;
 
-use pest::iterators::Pair;
 use pest::Parser;
 
 use vcore::opcodes::Opcode;
 
-use crate::ast::{Directive, Instruction, Node, Operator, VASMLine};
+use crate::ast::{Label, Node, VASMLine};
 use crate::parse_error::ParseError;
 
 #[derive(Parser)]
 #[grammar = "vasm.pest"]
 pub struct VASMParser;
 
+type Pair<'a> = pest::iterators::Pair<'a, Rule>;
+
+trait Children {
+    fn first(self) -> Self;
+    fn only(self) -> Self;
+}
+
+impl<'a> Children for Pair<'a> {
+    fn first(self) -> Self {
+        self.into_inner().next().unwrap()
+    }
+
+    fn only(self) -> Pair<'a> {
+        let mut iter = self.into_inner();
+        let child = iter.next().unwrap();
+        debug_assert_eq!(iter.next(), None);
+        child
+    }
+}
+
 /// Perform tree-shaking on a `Node` by recursively removing single-`Node` exprs.
 fn shake(node: Node) -> Node {
     match node {
@@ -29,79 +47,81 @@ fn shake(node: Node) -> Node {
     }
 }
 
+fn optional_label(pair: Option<Pair>) -> Option<Label> {
+    pair.map(|label| Label(label.only().as_str()))
+}
+
 pub fn parse_vasm_line(line: &str) -> Result<VASMLine, ParseError<'_>> {
-    let mut pairs = VASMParser::parse(Rule::line, line)
+    let line = VASMParser::parse(Rule::line, line)
         .map_err(|_| ParseError::LineParseFailure)?
         .next()
         .unwrap()
-        .into_inner()
+        .first();
-        .peekable();
 
-    let mut vasm_line = VASMLine::blank();
+    match line.as_rule() {
-
+        Rule::instruction => {
-    if let Some(label_group) = pairs.next_if(|pair| pair.as_rule() == Rule::label_group) {
+            let mut iter = line.into_inner().peekable();
-        let label = label_group.into_inner().next().unwrap();
+            let label = optional_label(iter.next_if(|pair| pair.as_rule() == Rule::label_def));
-        vasm_line = vasm_line.with_label(label.as_str())
+            let opcode = Opcode::try_from(
-    }
+                iter.next_if(|pair| pair.as_rule() == Rule::opcode)
-
+                    .unwrap()
-    if let Some(instruction_group) = pairs.next_if(|pair| pair.as_rule() == Rule::instruction_group)
+                    .as_str(),
-    {
+            )?;
-        let mut pairs = instruction_group.into_inner();
+            let argument = iter
-        vasm_line = vasm_line.with_instruction(Instruction::try_from(pairs.next().unwrap())?);
+                .next_if(|pair| pair.as_rule() == Rule::expr)
-
+                .map(|expr| shake(Node::from(expr)));
-        if let Some(argument_group) = pairs.next() {
+            return Ok(VASMLine::Instruction(label, opcode, argument));
-            vasm_line = vasm_line.with_argument(shake(Node::try_from(argument_group)?))
         }
+        Rule::db_directive => {
+            let mut iter = line.into_inner().peekable();
+            let label = optional_label(iter.next_if(|pair| pair.as_rule() == Rule::label_def));
+            let argument = shake(Node::from(iter.next().unwrap()));
+            return Ok(VASMLine::Db(label, argument));
+        }
+        Rule::org_directive => {
+            let mut iter = line.into_inner().peekable();
+            let label = optional_label(iter.next_if(|pair| pair.as_rule() == Rule::label_def));
+            let argument = shake(Node::from(iter.next().unwrap()));
+            return Ok(VASMLine::Org(label, argument));
+        }
+        Rule::equ_directive => {
+            let mut iter = line.into_inner();
+            let label = Label(iter.next().unwrap().only().as_str());
+            let argument = shake(Node::from(iter.next().unwrap()));
+            return Ok(VASMLine::Equ(label, argument));
+        }
+        Rule::label_def => {
+            return Ok(VASMLine::LabelDef(Label(line.only().as_str())));
+        }
+        _ => unreachable!(),
     }
-
-    Ok(vasm_line)
 }
 
 #[cfg(test)]
 mod test {
     use vcore::opcodes::Opcode::*;
 
-    use super::Directive::*;
     use super::*;
+    use crate::ast::Operator;
 
-    impl<'a> VASMLine<'a> {
+    fn number(number: i32) -> Node<'static> {
-        pub fn op(opcode: Opcode) -> VASMLine<'a> {
+        Node::Number(number)
-            Self::blank().with_opcode(opcode)
+    }
-        }
 
-        fn op_number(opcode: Opcode, argument: i32) -> VASMLine<'a> {
+    fn string(s: &str) -> Node<'static> {
-            Self::blank()
+        Node::String(s.to_string())
-                .with_opcode(opcode)
-                .with_argument(Node::Number(argument))
-        }
-
-        fn op_label(opcode: Opcode, argument: &'a str) -> VASMLine<'a> {
-            Self::blank()
-                .with_opcode(opcode)
-                .with_argument(Node::Label(argument))
-        }
-
-        fn op_rel_label(opcode: Opcode, argument: &'a str) -> VASMLine<'a> {
-            Self::blank()
-                .with_opcode(opcode)
-                .with_argument(Node::RelativeLabel(argument))
-        }
-
-        fn op_off(opcode: Opcode, argument: Node<'a>) -> VASMLine<'a> {
-            Self::blank().with_opcode(opcode).with_argument(argument)
-        }
-
-        pub fn dir_str(directive: Directive, string: &str) -> VASMLine<'a> {
-            Self::blank()
-                .with_directive(directive)
-                .with_argument(Node::String(string.to_string()))
-        }
     }
 
     #[test]
     fn test_parse() {
-        assert_eq!(parse_vasm_line("add"), Ok(VASMLine::op(Add)));
+        assert_eq!(
-        assert_eq!(parse_vasm_line("sub"), Ok(VASMLine::op(Sub)));
+            parse_vasm_line("add"),
+            Ok(VASMLine::Instruction(None, Add, None))
+        );
+        assert_eq!(
+            parse_vasm_line("sub"),
+            Ok(VASMLine::Instruction(None, Sub, None))
+        );
         assert_eq!(
             parse_vasm_line("blah"),
             Err(ParseError::InvalidInstruction("blah"))
@@ -111,61 +131,83 @@ mod test {
 
     #[test]
     fn test_numbers() {
-        assert_eq!(parse_vasm_line("add 45"), Ok(VASMLine::op_number(Add, 45)));
+        assert_eq!(
-        assert_eq!(parse_vasm_line("add 0"), Ok(VASMLine::op_number(Add, 0)));
+            parse_vasm_line("add 45"),
+            Ok(VASMLine::Instruction(None, Add, Some(number(45))))
+        );
+        assert_eq!(
+            parse_vasm_line("blah: add 45"),
+            Ok(VASMLine::Instruction(
+                Some(Label("blah")),
+                Add,
+                Some(number(45))
+            ))
+        );
+        assert_eq!(
+            parse_vasm_line("add 0"),
+            Ok(VASMLine::Instruction(None, Add, Some(number(0))))
+        );
         assert_eq!(
             parse_vasm_line("add 0x10"),
-            Ok(VASMLine::op_number(Add, 16))
+            Ok(VASMLine::Instruction(None, Add, Some(number(16))))
         );
         assert_eq!(
             parse_vasm_line("add 0b1111"),
-            Ok(VASMLine::op_number(Add, 15))
+            Ok(VASMLine::Instruction(None, Add, Some(number(15))))
         );
         assert_eq!(
             parse_vasm_line("add 0o377"),
-            Ok(VASMLine::op_number(Add, 255))
+            Ok(VASMLine::Instruction(None, Add, Some(number(255))))
         );
         assert_eq!(
             parse_vasm_line("add -17"),
-            Ok(VASMLine::op_number(Add, -17))
+            Ok(VASMLine::Instruction(None, Add, Some(number(-17))))
         );
     }
 
     #[test]
-    fn test_strings() {
+    fn test_dbs() {
         assert_eq!(
             parse_vasm_line(".db \"blah\""),
-            Ok(VASMLine::dir_str(Db, "blah"))
+            Ok(VASMLine::Db(None, string("blah")))
         );
         assert_eq!(
             parse_vasm_line(".db \"blah\\twith escapes\\0\""),
-            Ok(VASMLine::dir_str(Db, "blah\twith escapes\0"))
+            Ok(VASMLine::Db(None, string("blah\twith escapes\0")))
-        )
+        );
+        assert_eq!(
+            parse_vasm_line("foo: .db 47"),
+            Ok(VASMLine::Db(Some(Label("foo")), number(47)))
+        );
     }
 
     #[test]
     fn test_exprs() {
         assert_eq!(
             parse_vasm_line("add 2 + 3 * (4 - 5) + 6"),
-            Ok(VASMLine::op(Add).with_argument(Node::Expr(
+            Ok(VASMLine::Instruction(
-                Box::from(Node::Number(2)),
+                None,
-                vec![
+                Add,
-                    (
+                Some(Node::Expr(
-                        Operator::Add,
+                    Box::from(Node::Number(2)),
-                        Node::Expr(
+                    vec![
-                            Box::from(Node::Number(3)),
+                        (
-                            vec![(
+                            Operator::Add,
-                                Operator::Mul,
+                            Node::Expr(
-                                Node::Expr(
+                                Box::from(Node::Number(3)),
-                                    Box::from(Node::Number(4)),
+                                vec![(
-                                    vec![(Operator::Sub, Node::Number(5))],
+                                    Operator::Mul,
-                                )
+                                    Node::Expr(
-                            )],
+                                        Box::from(Node::Number(4)),
-                        )
+                                        vec![(Operator::Sub, Node::Number(5))],
-                    ),
+                                    )
-                    (Operator::Add, Node::Number(6))
+                                )],
-                ],
+                            )
-            )))
+                        ),
+                        (Operator::Add, Node::Number(6))
+                    ],
+                ))
+            ))
         );
     }
 
@@ -173,11 +215,15 @@ mod test {
     fn test_expr_labels() {
         assert_eq!(
             parse_vasm_line("loadw foo"),
-            Ok(VASMLine::op_label(Loadw, "foo"))
+            Ok(VASMLine::Instruction(None, Loadw, Some(Node::Label("foo"))))
         );
         assert_eq!(
             parse_vasm_line("brz @blah"),
-            Ok(VASMLine::op_rel_label(Brz, "blah"))
+            Ok(VASMLine::Instruction(
+                None,
+                Brz,
+                Some(Node::RelativeLabel("blah"))
+            ))
         )
     }
 
@@ -185,11 +231,19 @@ mod test {
     fn test_expr_offsets() {
         assert_eq!(
             parse_vasm_line("jmp $-2"),
-            Ok(VASMLine::op_off(Jmp, Node::AbsoluteOffset(-2)))
+            Ok(VASMLine::Instruction(
+                None,
+                Jmp,
+                Some(Node::AbsoluteOffset(-2))
+            ))
         );
         assert_eq!(
             parse_vasm_line("brz @+3"),
-            Ok(VASMLine::op_off(Brz, Node::RelativeOffset(3)))
+            Ok(VASMLine::Instruction(
+                None,
+                Brz,
+                Some(Node::RelativeOffset(3))
+            ))
         )
     }
 
@@ -197,27 +251,31 @@ mod test {
     fn test_parse_labels() {
         assert_eq!(
             parse_vasm_line("foo: add"),
-            Ok(VASMLine::op(Add).with_label("foo"))
+            Ok(VASMLine::Instruction(Some(Label("foo")), Add, None))
         );
         assert_eq!(
             parse_vasm_line("bar:"),
-            Ok(VASMLine::blank().with_label("bar"))
+            Ok(VASMLine::LabelDef(Label("bar")))
         );
         assert_eq!(
             parse_vasm_line("foo: add 43"),
-            Ok(VASMLine::op_number(Add, 43).with_label("foo"))
+            Ok(VASMLine::Instruction(
+                Some(Label("foo")),
+                Add,
+                Some(number(43))
+            ))
         );
     }
 
     #[test]
     fn test_parse_directives() {
         assert_eq!(
-            parse_vasm_line("foo: .equ"),
+            parse_vasm_line("foo: .equ 47"),
-            Ok(VASMLine::blank().with_label("foo").with_directive(Equ))
+            Ok(VASMLine::Equ(Label("foo"), number(47)))
         );
         assert_eq!(
-            parse_vasm_line(".db"),
+            parse_vasm_line(".org 0x400"),
-            Ok(VASMLine::blank().with_directive(Db))
+            Ok(VASMLine::Org(None, number(1024)))
         );
     }
 }

vcore/src/cpu.rs

@@ -112,6 +112,10 @@ impl CPU {
         }
     }
 
+    #[allow(clippy::cmp_owned)]
+    // This is needed because clippy can't figure out, on alt / agt, that even though yes you can
+    // directly compare two Words, that means something different than comparing the i32s those
+    // Words represent. That difference is the entire point of the agt / alt instructions.
     fn execute(&mut self, instruction: Instruction) -> Word {
         if let Some(arg) = instruction.arg {
             self.push_data(arg)
@@ -242,7 +246,9 @@ impl CPU {
     }
 
     pub fn tick(&mut self) {
-        if self.halted { return }
+        if self.halted {
+            return;
+        }
 
         match self.fetch() {
             Ok(instr) => {
@@ -329,7 +335,7 @@ mod tests {
         let mut cpu = CPU::new(Memory::default());
         given(&mut cpu);
         let new_pc = cpu.execute(Instruction {
-            opcode: opcode,
+            opcode,
             arg: None,
             length: 1,
         });
@@ -501,8 +507,10 @@ mod tests {
         simple_opcode_test(vec![5, 3], Lt, vec![0]);
         simple_opcode_test(vec![5, 7], Lt, vec![1]);
         simple_opcode_test(vec![5, to_word(-3)], Agt, vec![1]);
+        simple_opcode_test(vec![to_word(-3), 5], Agt, vec![0]);
         simple_opcode_test(vec![5, 10], Agt, vec![0]);
         simple_opcode_test(vec![5, to_word(-3)], Alt, vec![0]);
+        simple_opcode_test(vec![to_word(-3), 5], Alt, vec![1]);
         simple_opcode_test(vec![5, 10], Alt, vec![1]);
         simple_opcode_test(vec![0b1100, 2], Rshift, vec![3]);
         simple_opcode_test(vec![0b1100, 2], Lshift, vec![0b110000]);
@@ -541,7 +549,7 @@ mod tests {
     fn test_cpu_new() {
         let cpu = CPU::new(Memory::default());
         assert_eq!(cpu.pc, 1024);
-        assert_eq!(cpu.halted, true);
+        assert!(cpu.halted);
     }
 
     #[test]

vcore/src/word.rs

@@ -12,7 +12,7 @@ impl Word {
     /// ```
     /// use vcore::word::Word;
     ///
-    /// assert!(Word::from_bytes([0x01, 0x02, 0x03]) == 0x030201);
+    /// assert_eq!(Word::from_bytes([0x01, 0x02, 0x03]), 0x030201);
     /// ```
     pub fn from_bytes(bytes: [u8; 3]) -> Self {
         let [a, b, c] = bytes;
@@ -130,9 +130,9 @@ impl From<Word> for bool {
 
 #[test]
 fn to_from_bool() {
-    assert_eq!(bool::from(Word::from(0)), false);
+    assert!(!bool::from(Word::from(0)));
-    assert_eq!(bool::from(Word::from(1)), true);
+    assert!(bool::from(Word::from(1)));
-    assert_eq!(bool::from(Word::from(0x123456)), true);
+    assert!(bool::from(Word::from(0x123456)));
 
     assert_eq!(Word::from(false), Word::from(0));
     assert_eq!(Word::from(true), Word::from(1));