Improved parameter handling

src/core/Function_test.go

@@ -12,9 +12,14 @@ func TestFunction(t *testing.T) {
 	b := build.New("../../examples/hello")
 	env, err := compiler.Compile(b)
 	assert.Nil(t, err)
+
 	main, exists := env.Functions["main.main"]
 	assert.True(t, exists)
 	assert.False(t, main.IsExtern())
 	assert.Equal(t, main.UniqueName, "main.main")
 	assert.Equal(t, main.String(), main.UniqueName)
+
+	write, exists := env.Functions["io.write"]
+	assert.True(t, exists)
+	write.Output[0].Type()
 }

src/core/Parameter.go

@@ -7,22 +7,12 @@ import (
 
 // Parameter is an input or output parameter in a function.
 type Parameter struct {
-	name   string
-	typ    types.Type
-	tokens token.List
+	Name       string
+	TypeTokens token.List
+	typ        types.Type
 }
 
-// NewParameter creates a new parameter with the given list of tokens.
-func NewParameter(tokens token.List) *Parameter {
-	return &Parameter{tokens: tokens}
-}
-
-// Name returns the name of the parameter.
-func (p *Parameter) Name() string {
-	return p.name
-}
-
-// Type returns the type of the parameter.
+// Type returns the data type of the parameter.
 func (p *Parameter) Type() types.Type {
 	return p.typ
 }

src/scanner/errors_test.go

@@ -32,6 +32,8 @@ var errs = []struct {
 	{"MissingParameter.q", scanner.MissingParameter},
 	{"MissingParameter2.q", scanner.MissingParameter},
 	{"MissingParameter3.q", scanner.MissingParameter},
+	{"MissingParameter4.q", scanner.MissingParameter},
+	{"MissingParameter5.q", scanner.MissingParameter},
 	{"MissingType.q", scanner.MissingType},
 }
 

src/scanner/scanSignature.go

@@ -63,7 +63,7 @@ func scanSignature(file *fs.File, tokens token.List, i int, delimiter token.Kind
 				return nil, i, errors.New(InvalidFunctionDefinition, file, tokens[i].Position)
 			}
 
-			return nil, i, nil
+			return nil, i, errors.New(InvalidFunctionDefinition, file, tokens[i].Position)
 		}
 
 		if groupLevel > 0 {
@@ -98,7 +98,10 @@ func scanSignature(file *fs.File, tokens token.List, i int, delimiter token.Kind
 			return nil, i, errors.New(MissingType, file, param[0].End())
 		}
 
-		function.Input = append(function.Input, core.NewParameter(param))
+		function.Input = append(function.Input, &core.Parameter{
+			Name:       param[0].String(file.Bytes),
+			TypeTokens: param[1:],
+		})
 	}
 
 	if typeStart != -1 {
@@ -109,8 +112,30 @@ func scanSignature(file *fs.File, tokens token.List, i int, delimiter token.Kind
 
 		outputTokens := tokens[typeStart:typeEnd]
 
+		if len(outputTokens) == 0 {
+			return nil, i, errors.New(MissingParameter, file, tokens[typeStart].Position)
+		}
+
+		errorPos := token.Position(typeStart)
+
 		for param := range outputTokens.Split {
-			function.Output = append(function.Output, core.NewParameter(param))
+			if len(param) == 0 {
+				return nil, i, errors.New(MissingParameter, file, errorPos)
+			}
+
+			if len(param) == 1 {
+				function.Output = append(function.Output, &core.Parameter{
+					Name:       "",
+					TypeTokens: param,
+				})
+			} else {
+				function.Output = append(function.Output, &core.Parameter{
+					Name:       param[0].String(file.Bytes),
+					TypeTokens: param[1:],
+				})
+			}
+
+			errorPos = param[len(param)-1].End() + 1
 		}
 	}
 

src/scanner/testdata/errors/MissingParameter4.q

@@ -0,0 +1 @@
+f() -> {}

src/scanner/testdata/errors/MissingParameter5.q

@@ -0,0 +1 @@
+f() -> (int,) {}