umx_compiler

commit 5cbae63c67263f473fbfb7a5ec45e0d11a144c12
parent 70b2cc1df065a909998e5db015454daa8d591c44
Author: bsandro <email@bsandro.tech>
Date:   Thu, 23 Jun 2022 04:04:42 +0300

primitive integer eval

Diffstat:
A
eval/eval.go
 | 
26
++++++++++++++++++++++++++
A
eval/eval_test.go
 | 
42
++++++++++++++++++++++++++++++++++++++++++
A
object/object.go
 | 
32
++++++++++++++++++++++++++++++++

3 files changed, 100 insertions(+), 0 deletions(-)
diff --git a/eval/eval.go b/eval/eval.go
@@ -0,0 +1,26 @@
+package eval
+
+import (
+	"interp/ast"
+	"interp/object"
+)
+
+func Eval(node ast.Node) object.Object {
+	switch node := node.(type) {
+	case *ast.Program:
+		return evalStatements(node.Statements)
+	case *ast.ExpressionStatement:
+		return Eval(node.Expression)
+	case *ast.IntegerLiteral:
+		return &object.Integer{Value: node.Value}
+	}
+	return nil
+}
+
+func evalStatements(statements []ast.Statement) object.Object {
+	var result object.Object
+	for _,statement := range statements {
+		result = Eval(statement)
+	}
+	return result
+}
diff --git a/eval/eval_test.go b/eval/eval_test.go
@@ -0,0 +1,42 @@
+package eval
+
+import (
+	"interp/lexer"
+	"interp/parser"
+	"interp/object"
+	"testing"
+)
+
+func TestEvalIntegerExpression(t *testing.T) {
+	tests := []struct{
+		input string
+		expected int64
+	}{
+		{"6", 6},
+		{"10", 10},
+	}
+	for _, tt := range tests {
+		evaluated := testEval(tt.input)
+		testIntegerObject(t, evaluated, tt.expected)
+	}
+}
+
+func testEval(input string) object.Object {
+	l := lexer.New(input)
+	p := parser.New(l)
+	prg := p.ParseProgram()
+	return Eval(prg)
+}
+
+func testIntegerObject(t *testing.T, obj object.Object, expected int64) bool {
+	result, ok := obj.(*object.Integer)
+	if !ok {
+		t.Errorf("obj is not integer (%T %+v)", obj, obj)
+		return false
+	}
+	if result.Value != expected {
+		t.Errorf("obj has wrong value (%d instead of %d)", result.Value, expected)
+		return false
+	}
+	return true
+}
diff --git a/object/object.go b/object/object.go
@@ -0,0 +1,32 @@
+package object
+
+import "fmt"
+
+type ObjectType string
+
+const (
+	INTEGER_OBJ = "INTEGER"
+	BOOLEAN_OBJ = "BOOLEAN"
+	NULL_OBJ = "NULL"
+)
+
+type Object interface {
+	Type() ObjectType
+	Inspect() string
+}
+
+type Integer struct {
+	Value int64
+}
+func (i *Integer) Inspect() string { return fmt.Sprintf("%d", i.Value) }
+func (i *Integer) Type() ObjectType { return INTEGER_OBJ }
+
+type Boolean struct {
+	Value bool
+}
+func (b *Boolean) Inspect() string { return fmt.Sprintf("%t", b.Value) }
+func (b *Boolean) Type() ObjectType { return BOOLEAN_OBJ }
+
+type Null struct {}
+func (n *Null) Inspect() string { return "null" }
+func (n *Null) Type() ObjectType { return NULL_OBJ }