examples/basic/negation.ngr

@@ -0,0 +1,3 @@
+x = 2i64 + 2i64;
+y = -x;
+print y;

src/backend/eval.rs

@@ -1,10 +1,9 @@
-use std::path::Path;
-
 use crate::backend::Backend;
 use crate::eval::EvalError;
 use crate::ir::Program;
 use cranelift_jit::JITModule;
 use cranelift_object::ObjectModule;
+use std::path::Path;
 use target_lexicon::Triple;
 
 impl Backend<JITModule> {
@@ -127,6 +126,16 @@ proptest::proptest! {
         let basic_result = basic_result.map(|x| x.replace('\n', "\r\n"));
 
         if !matches!(basic_result, Err(EvalError::PrimOp(PrimOpError::MathFailure(_)))) {
+//            use pretty::{DocAllocator, Pretty};
+//            let allocator = pretty::BoxAllocator;
+//            allocator
+//              .text("---------------")
+//              .append(allocator.hardline())
+//              .append(program.pretty(&allocator))
+//              .1
+//              .render_colored(70, pretty::termcolor::StandardStream::stdout(pretty::termcolor::ColorChoice::Auto))
+//              .expect("rendering works");
+
             let compiled_result = Backend::<ObjectModule>::eval(program);
             assert_eq!(basic_result, compiled_result);
         }

src/backend/into_crane.rs

@@ -308,28 +308,39 @@ impl Expression {
             }
 
             Expression::Primitive(_, prim, mut vals) => {
-                // we're going to use `pop`, so we're going to pull and compile the right value ...
+                let mut values = vec![];
-                let (right, rtype) =
+                let mut first_type = None;
-                    vals.pop()
+
-                        .unwrap()
+                for val in vals.drain(..) {
-                        .into_crane(builder, local_variables, global_variables)?;
+                    let (compiled, compiled_type) =
-                // ... and then the left.
+                        val.into_crane(builder, local_variables, global_variables)?;
-                let (left, ltype) =
+
-                    vals.pop()
+                    if let Some(leftmost_type) = first_type {
-                        .unwrap()
+                        assert_eq!(leftmost_type, compiled_type);
-                        .into_crane(builder, local_variables, global_variables)?;
+                    } else {
+                        first_type = Some(compiled_type);
+                    }
+
+                    values.push(compiled);
+                }
+
+                let first_type = first_type.expect("primitive op has at least one argument");
 
-                assert_eq!(rtype, ltype, "primitive argument types match");
                 // then we just need to tell Cranelift how to do each of our primitives! Much
                 // like Statements, above, we probably want to eventually shuffle this off into
                 // a separate function (maybe something off `Primitive`), but for now it's simple
                 // enough that we just do the `match` here.
                 match prim {
-                    Primitive::Plus => Ok((builder.ins().iadd(left, right), ltype)),
+                    Primitive::Plus => Ok((builder.ins().iadd(values[0], values[1]), first_type)),
-                    Primitive::Minus => Ok((builder.ins().isub(left, right), ltype)),
+                    Primitive::Minus if values.len() == 2 => {
-                    Primitive::Times => Ok((builder.ins().imul(left, right), ltype)),
+                        Ok((builder.ins().isub(values[0], values[1]), first_type))
-                    Primitive::Divide if rtype.is_signed() => Ok((builder.ins().sdiv(left, right), ltype)),
+                    }
-                    Primitive::Divide => Ok((builder.ins().udiv(left, right), ltype)),
+                    Primitive::Minus => Ok((builder.ins().ineg(values[0]), first_type)),
+                    Primitive::Times => Ok((builder.ins().imul(values[0], values[1]), first_type)),
+                    Primitive::Divide if first_type.is_signed() => {
+                        Ok((builder.ins().sdiv(values[0], values[1]), first_type))
+                    }
+                    Primitive::Divide => Ok((builder.ins().udiv(values[0], values[1]), first_type)),
                 }
             }
         }

src/eval/primop.rs

@@ -59,6 +59,19 @@ macro_rules! run_op {
 }
 
 impl Value {
+    fn unary_op(operation: &str, value: &Value) -> Result<Value, PrimOpError> {
+        match operation {
+            "-" => match value {
+                Value::I8(x) => Ok(Value::I8(-x)),
+                Value::I16(x) => Ok(Value::I16(-x)),
+                Value::I32(x) => Ok(Value::I32(-x)),
+                Value::I64(x) => Ok(Value::I64(-x)),
+                _ => Err(PrimOpError::BadTypeFor("-", value.clone())),
+            },
+            _ => Err(PrimOpError::BadArgCount(operation.to_owned(), 1)),
+        }
+    }
+
     fn binary_op(operation: &str, left: &Value, right: &Value) -> Result<Value, PrimOpError> {
         match left {
             Value::I8(x) => match right {
@@ -137,13 +150,10 @@ impl Value {
     /// its worth being careful to make sure that your inputs won't cause either
     /// condition.
     pub fn calculate(operation: &str, values: Vec<Value>) -> Result<Value, PrimOpError> {
-        if values.len() == 2 {
+        match values.len() {
-            Value::binary_op(operation, &values[0], &values[1])
+            1 => Value::unary_op(operation, &values[0]),
-        } else {
+            2 => Value::binary_op(operation, &values[0], &values[1]),
-            Err(PrimOpError::BadArgCount(
+            x => Err(PrimOpError::BadArgCount(operation.to_string(), x)),
-                operation.to_string(),
-                values.len(),
-            ))
         }
     }
 }

src/examples.rs

@@ -1,7 +1,7 @@
-use codespan_reporting::files::SimpleFiles;
 use crate::backend::Backend;
 use crate::ir::Program as IR;
 use crate::syntax::Program as Syntax;
+use codespan_reporting::files::SimpleFiles;
 use cranelift_jit::JITModule;
 
 include!(concat!(env!("OUT_DIR"), "/examples.rs"));

src/syntax/arbitrary.rs

@@ -8,6 +8,7 @@ use proptest::{
 use std::collections::HashMap;
 
 const VALID_VARIABLE_NAMES: &str = r"[a-z][a-zA-Z0-9_]*";
+const OPERATORS: &[(&str, usize)] = &[("+", 2), ("-", 1), ("-", 2), ("*", 2), ("/", 2)];
 
 #[derive(Debug)]
 struct Name(String);
@@ -26,40 +27,34 @@ impl Arbitrary for Program {
     type Strategy = BoxedStrategy<Self>;
 
     fn arbitrary_with(_: Self::Parameters) -> Self::Strategy {
-        let optionals = Vec::<Option<(Name, ConstantType)>>::arbitrary();
+        let optionals = Vec::<(Name, ConstantType, u8)>::arbitrary();
 
         optionals
             .prop_flat_map(|mut possible_names| {
                 let mut statements = Vec::new();
                 let mut defined_variables: HashMap<String, ConstantType> = HashMap::new();
 
-                for possible_name in possible_names.drain(..) {
+                for (possible_name, possible_type, dice_roll) in possible_names.drain(..) {
-                    match possible_name {
+                    if !defined_variables.is_empty() && dice_roll < 100 {
-                        None if defined_variables.is_empty() => continue,
+                        statements.push(
-                        None => statements.push(
                             Union::new(defined_variables.keys().map(|name| {
                                 Just(Statement::Print(Location::manufactured(), name.to_string()))
                             }))
                             .boxed(),
-                        ),
+                        );
-                        Some((new_name, new_type)) => {
+                    } else {
-                            let closures_name = new_name.0.clone();
+                        let closures_name = possible_name.0.clone();
-                            let retval = Expression::arbitrary_with((
+                        let retval = Expression::arbitrary_with((
-                                Some(defined_variables.clone()),
+                            Some(defined_variables.clone()),
-                                Some(new_type),
+                            Some(possible_type),
-                            ))
+                        ))
-                            .prop_map(move |exp| {
+                        .prop_map(move |exp| {
-                                Statement::Binding(
+                            Statement::Binding(Location::manufactured(), closures_name.clone(), exp)
-                                    Location::manufactured(),
+                        })
-                                    closures_name.clone(),
+                        .boxed();
-                                    exp,
-                                )
-                            })
-                            .boxed();
 
-                            defined_variables.insert(new_name.0, new_type);
+                        defined_variables.insert(possible_name.0, possible_type);
-                            statements.push(retval);
+                        statements.push(retval);
-                        }
                     }
                 }
 
@@ -131,13 +126,28 @@ impl Arbitrary for Expression {
 
         leaf_strategy
             .prop_recursive(3, 64, 2, move |inner| {
-                (
+                (select(OPERATORS), proptest::collection::vec(inner, 2)).prop_map(
-                    select(super::BINARY_OPERATORS),
+                    move |((operator, arg_count), mut exprs)| {
-                    proptest::collection::vec(inner, 2),
+                        if arg_count == 1 && operator == "-" {
+                            if target_type.map(|x| x.is_signed()).unwrap_or(false) {
+                                Expression::Primitive(
+                                    Location::manufactured(),
+                                    operator.to_string(),
+                                    exprs,
+                                )
+                            } else {
+                                exprs.pop().unwrap()
+                            }
+                        } else {
+                            exprs.truncate(arg_count);
+                            Expression::Primitive(
+                                Location::manufactured(),
+                                operator.to_string(),
+                                exprs,
+                            )
+                        }
+                    },
                 )
-                    .prop_map(move |(operator, exprs)| {
-                        Expression::Primitive(Location::manufactured(), operator.to_string(), exprs)
-                    })
             })
             .boxed()
     }

src/syntax/ast.rs

@@ -1,9 +1,6 @@
 pub use crate::syntax::tokens::ConstantType;
 use crate::syntax::Location;
 
-/// The set of valid binary operators.
-pub static BINARY_OPERATORS: &[&str] = &["+", "-", "*", "/"];
-
 /// A structure represented a parsed program.
 ///
 /// One `Program` is associated with exactly one input file, and the

src/syntax/parser.lalrpop

@@ -133,14 +133,14 @@ AdditiveExpression: Expression = {
 
 // similarly, we group multiplication and division under "multiplicative"
 MultiplicativeExpression: Expression = {
-    <e1:MultiplicativeExpression> <l:@L> "*" <e2:AtomicExpression> => Expression::Primitive(Location::new(file_idx, l), "*".to_string(), vec![e1, e2]),
+    <e1:MultiplicativeExpression> <l:@L> "*" <e2:UnaryExpression> => Expression::Primitive(Location::new(file_idx, l), "*".to_string(), vec![e1, e2]),
-    <e1:MultiplicativeExpression> <l:@L> "/" <e2:AtomicExpression> => Expression::Primitive(Location::new(file_idx, l), "/".to_string(), vec![e1, e2]),
+    <e1:MultiplicativeExpression> <l:@L> "/" <e2:UnaryExpression> => Expression::Primitive(Location::new(file_idx, l), "/".to_string(), vec![e1, e2]),
-    AtomicExpression,
+    UnaryExpression,
 }
 
 UnaryExpression: Expression = {
-    <l:@L> "-" <e:MultiplicativeExpression> => Expression::Primitive(Location::new(file_idx, l), "-".to_string(), vec![e]),
+    <l:@L> "-" <e:UnaryExpression> => Expression::Primitive(Location::new(file_idx, l), "-".to_string(), vec![e]),
-    <l:@L> "<" <v:"<var>"> ">" <e:MultiplicativeExpression> => Expression::Cast(Location::new(file_idx, l), v.to_string(), Box::new(e)),
+    <l:@L> "<" <v:"<var>"> ">" <e:UnaryExpression> => Expression::Cast(Location::new(file_idx, l), v.to_string(), Box::new(e)),
     AtomicExpression,
 }
 

src/syntax/pretty.rs

@@ -1,4 +1,4 @@
-use crate::syntax::ast::{Expression, Program, Statement, Value, BINARY_OPERATORS};
+use crate::syntax::ast::{Expression, Program, Statement, Value};
 use pretty::{DocAllocator, DocBuilder, Pretty};
 
 use super::ConstantType;
@@ -56,14 +56,10 @@ where
                 .text(t.clone())
                 .angles()
                 .append(e.pretty(allocator)),
-            Expression::Primitive(_, op, exprs) if BINARY_OPERATORS.contains(&op.as_ref()) => {
+            Expression::Primitive(_, op, exprs) if exprs.len() == 1 => allocator
-                assert_eq!(
+                .text(op.to_string())
-                    exprs.len(),
+                .append(exprs[0].pretty(allocator)),
-                    2,
+            Expression::Primitive(_, op, exprs) if exprs.len() == 2 => {
-                    "Found binary operator with {} components?",
-                    exprs.len()
-                );
-
                 let left = exprs[0].pretty(allocator);
                 let right = exprs[1].pretty(allocator);
 

src/syntax/tokens.rs

@@ -170,7 +170,10 @@ impl From<ConstantType> for cranelift_codegen::ir::Type {
 impl ConstantType {
     /// Returns true if the given type is (a) numeric and (b) signed;
     pub fn is_signed(&self) -> bool {
-        matches!(self, ConstantType::I8 | ConstantType::I16 | ConstantType::I32 | ConstantType::I64)
+        matches!(
+            self,
+            ConstantType::I8 | ConstantType::I16 | ConstantType::I32 | ConstantType::I64
+        )
     }
 }
 
@@ -289,3 +292,28 @@ fn lexer_spans() {
     assert_eq!(lex0.next(), Some((Token::Number((None, None, 1)), 8..9)));
     assert_eq!(lex0.next(), None);
 }
+
+#[test]
+fn further_spans() {
+    let mut lex0 = Token::lexer("x = 2i64 + 2i64;\ny = -x;\nprint y;").spanned();
+    assert_eq!(lex0.next(), Some((Token::var("x"), 0..1)));
+    assert_eq!(lex0.next(), Some((Token::Equals, 2..3)));
+    assert_eq!(
+        lex0.next(),
+        Some((Token::Number((None, Some(ConstantType::I64), 2)), 4..8))
+    );
+    assert_eq!(lex0.next(), Some((Token::Operator('+'), 9..10)));
+    assert_eq!(
+        lex0.next(),
+        Some((Token::Number((None, Some(ConstantType::I64), 2)), 11..15))
+    );
+    assert_eq!(lex0.next(), Some((Token::Semi, 15..16)));
+    assert_eq!(lex0.next(), Some((Token::var("y"), 17..18)));
+    assert_eq!(lex0.next(), Some((Token::Equals, 19..20)));
+    assert_eq!(lex0.next(), Some((Token::Operator('-'), 21..22)));
+    assert_eq!(lex0.next(), Some((Token::var("x"), 22..23)));
+    assert_eq!(lex0.next(), Some((Token::Semi, 23..24)));
+    assert_eq!(lex0.next(), Some((Token::Print, 25..30)));
+    assert_eq!(lex0.next(), Some((Token::var("y"), 31..32)));
+    assert_eq!(lex0.next(), Some((Token::Semi, 32..33)));
+}