Improves parser tests

jamillosantos · Dec 6, 2017 · a5ef363 · a5ef363
1 parent 09cf82d
commit a5ef363
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Showing 2 changed files with 24 additions and 24 deletions.
diff --git a/parser.go b/parser.go
@@ -8,7 +8,7 @@ import (
 
 type ExpressionError error
 
-func newExpression(expression antlr.Tree) Expression {
+func NewExpression(expression antlr.Tree) Expression {
 	switch e := expression.(type) {
 	case *parser.VariableContext:
 		return &ExpressionField{
@@ -19,61 +19,57 @@ func newExpression(expression antlr.Tree) Expression {
 		return NewExpressionValue(v)
 	case *parser.AtomContext:
 		if e.GetChildCount() == 1 {
-			return newExpression(e.GetChild(0))
+			return NewExpression(e.GetChild(0))
 		} else {
-			return newExpression(e.GetChild(1))
+			return NewExpression(e.GetChild(1))
 		}
 	case *parser.SignedAtomContext:
 		if e.GetChildCount() == 1 {
-			return newExpression(e.GetChild(0))
-		} else if e.GetChildCount() == 2 {
-			expr := NewExpressionMultiple()
-			expr.Add("", NewExpressionValue(0))
-			expr.Add(e.GetOperator().GetText(), newExpression(e.GetChild(1)))
-			return expr
-		} else {
-			// TODO
-			panic("TODO! " + e.GetText())
+			return NewExpression(e.GetChild(0))
 		}
+		expr := NewExpressionMultiple()
+		expr.Add("", NewExpressionValue(0))
+		expr.Add(e.GetOperator().GetText(), NewExpression(e.GetChild(1)))
+		return expr
 	case *parser.ExpressionContext:
 		if e.GetChildCount() == 1 {
-			return newExpression(e.GetChild(0))
+			return NewExpression(e.GetChild(0))
 		} else {
 			r := NewExpressionMultiple()
 			for i, me := range e.AllMultiplyingExpression() {
 				if i == 0 {
-					r.Add("", newExpression(me))
+					r.Add("", NewExpression(me))
 				} else {
-					r.Add(e.GetChild(i*2 - 1).(*antlr.TerminalNodeImpl).GetText(), newExpression(me))
+					r.Add(e.GetChild(i*2 - 1).(*antlr.TerminalNodeImpl).GetText(), NewExpression(me))
 				}
 			}
 			return r
 		}
 	case *parser.MultiplyingExpressionContext:
 		childCount := e.GetChildCount()
 		if childCount == 1 {
-			return newExpression(e.GetChild(0))
+			return NewExpression(e.GetChild(0))
 		} else {
 			r := NewExpressionMultiple()
 			for i, me := range e.AllPowExpression() {
 				if i == 0 {
-					r.Add("", newExpression(me))
+					r.Add("", NewExpression(me))
 				} else {
-					r.Add(e.GetChild(i*2 - 1).(*antlr.TerminalNodeImpl).GetText(), newExpression(me))
+					r.Add(e.GetChild(i*2 - 1).(*antlr.TerminalNodeImpl).GetText(), NewExpression(me))
 				}
 			}
 			return r
 		}
 	case *parser.PowExpressionContext:
 		if e.GetChildCount() == 1 {
-			return newExpression(e.GetChild(0))
+			return NewExpression(e.GetChild(0))
 		} else {
 			r := NewExpressionMultiple()
 			for i, me := range e.AllSignedAtom() {
 				if i == 0 {
-					r.Add("", newExpression(me))
+					r.Add("", NewExpression(me))
 				} else {
-					r.Add(e.GetChild(i*2 - 1).(*antlr.TerminalNodeImpl).GetText(), newExpression(me))
+					r.Add(e.GetChild(i*2 - 1).(*antlr.TerminalNodeImpl).GetText(), NewExpression(me))
 				}
 			}
 			return r
@@ -82,12 +78,12 @@ func newExpression(expression antlr.Tree) Expression {
 		eParams := e.AllExpression()
 		params := make([]Expression, 0, len(eParams))
 		for _, p := range eParams {
-			params = append(params, newExpression(p))
+			params = append(params, NewExpression(p))
 		}
 		return NewExpressionFunction(e.GetFname().GetText(), params...)
 	case *parser.BinaryOpContext:
 		atoms := e.AllAtom()
-		return NewExpressionBinary(newExpression(atoms[0]), e.Relop().GetText(), newExpression(atoms[1]))
+		return NewExpressionBinary(NewExpression(atoms[0]), e.Relop().GetText(), NewExpression(atoms[1]))
 	case *parser.StrContext:
 		str := e.GetText()
 		return NewExpressionValue(str[1:len(str)-1])
@@ -102,5 +98,5 @@ func Compile(expression string) (Expression, error) {
 	p := parser.NewExpressionParser(stream)
 	p.AddErrorListener(antlr.NewDiagnosticErrorListener(true))
 	p.BuildParseTrees = true
-	return newExpression(p.Expression()), nil
+	return NewExpression(p.Expression()), nil
 }
diff --git a/parser_test.go b/parser_test.go
@@ -14,6 +14,10 @@ func TestCompile(t *testing.T) {
 	RegisterFailHandler(func(m string, _ ...int) { g.Fail(m) })
 
 	g.Describe("Compile", func() {
+		g.It("should return a nil expression", func() {
+			Expect(expressions.NewExpression(nil)).To(BeNil())
+		})
+
 		g.It("should resolve a simple equation with additions and subtractions", func() {
 			expr, err := expressions.Compile("1 + 2 - 3 + 4 - 5 + 6")
 			Expect(err).To(BeNil())