TrueCloudLab/neoneo-go
7
0
Fork 2
Code Issues Pull requests Projects Releases Packages Wiki Activity

Merge pull request #658 from nspcc-dev/feature/range

Browse source 
compiler: support for-range loops
This commit is contained in:
Roman Khimov 2020-02-16 23:49:30 +03:00 • committed by GitHub
commit 4a4cd6416c
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
2 changed files with 122 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

39
pkg/compiler/codegen.go
View file

@ -660,6 +660,45 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
return nil
case *ast.RangeStmt:
// currently only simple for-range loops are supported
// for i := range ...
if n.Value != nil {
c.prog.Err = errors.New("range loops with value variable are not supported")
return nil
}
start := c.newLabel()
end := c.newLabel()
ast.Walk(c, n.X)
emit.Opcode(c.prog.BinWriter, opcode.ARRAYSIZE)
emit.Opcode(c.prog.BinWriter, opcode.PUSH0)
c.setLabel(start)
emit.Opcode(c.prog.BinWriter, opcode.OVER)
emit.Opcode(c.prog.BinWriter, opcode.OVER)
emit.Opcode(c.prog.BinWriter, opcode.LTE) // finish if len <= i
emit.Jmp(c.prog.BinWriter, opcode.JMPIF, int16(end))
if n.Key != nil {
emit.Opcode(c.prog.BinWriter, opcode.DUP)
pos := c.scope.loadLocal(n.Key.(*ast.Ident).Name)
c.emitStoreLocal(pos)
}
ast.Walk(c, n.Body)
emit.Opcode(c.prog.BinWriter, opcode.INC)
emit.Jmp(c.prog.BinWriter, opcode.JMP, int16(start))
c.setLabel(end)
return nil
// We dont really care about assertions for the core logic.
// The only thing we need is to please the compiler type checking.
// For this to work properly, we only need to walk the expression