diff --git a/pkg/compiler/codegen.go b/pkg/compiler/codegen.go index 9a9b3aa61..3d1fd43d5 100644 --- a/pkg/compiler/codegen.go +++ b/pkg/compiler/codegen.go @@ -309,6 +309,29 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor { } return nil + case *ast.SliceExpr: + name := n.X.(*ast.Ident).Name + c.emitLoadLocal(name) + + if n.Low != nil { + ast.Walk(c, n.Low) + } else { + emit.Opcode(c.prog.BinWriter, opcode.PUSH0) + } + + if n.High != nil { + ast.Walk(c, n.High) + } else { + emit.Opcode(c.prog.BinWriter, opcode.OVER) + emit.Opcode(c.prog.BinWriter, opcode.ARRAYSIZE) + } + + emit.Opcode(c.prog.BinWriter, opcode.OVER) + emit.Opcode(c.prog.BinWriter, opcode.SUB) + emit.Opcode(c.prog.BinWriter, opcode.SUBSTR) + + return nil + case *ast.ReturnStmt: l := c.newLabel() c.setLabel(l) diff --git a/pkg/compiler/slice_test.go b/pkg/compiler/slice_test.go index 1fc3abc5b..a9b0ce8f8 100644 --- a/pkg/compiler/slice_test.go +++ b/pkg/compiler/slice_test.go @@ -69,6 +69,65 @@ var sliceTestCases = []testCase{ `, big.NewInt(15), }, + { + "sub-slice with literal bounds", + ` + package foo + func Main() []byte { + a := []byte{0, 1, 2, 3} + b := a[1:3] + return b + }`, + []byte{1, 2}, + }, + { + "sub-slice with constant bounds", + ` + package foo + const x = 1 + const y = 3 + func Main() []byte { + a := []byte{0, 1, 2, 3} + b := a[x:y] + return b + }`, + []byte{1, 2}, + }, + { + "sub-slice with variable bounds", + ` + package foo + func Main() []byte { + a := []byte{0, 1, 2, 3} + x := 1 + y := 3 + b := a[x:y] + return b + }`, + []byte{1, 2}, + }, + { + "sub-slice with no lower bound", + ` + package foo + func Main() []byte { + a := []byte{0, 1, 2, 3} + b := a[:3] + return b + }`, + []byte{0, 1, 2}, + }, + { + "sub-slice with no upper bound", + ` + package foo + func Main() []byte { + a := []byte{0, 1, 2, 3} + b := a[2:] + return b + }`, + []byte{2, 3}, + }, } func TestSliceOperations(t *testing.T) {