korzio

Microservices with GRPC/Go by Andrew

• Overview

  • Use case - notify slack with time management

• Project idea

  • Time management with no extra costs
  • On-premise project

• Alternatives

korzio

// iota enumerator gives an effective way in go language
// to use constants in enum-like constructs
const (
  none = iota
  plus
  mul
)
// enum-like map of operator token keys and iota values defined above
var precendences = map[string]int{
  token.PLUS:     plus,

korzio

func led(left ast.Node, operator token.Token, right ast.Node) *ast.Node {
  return &ast.Node{Left: &left, Token: &operator, Right: &right}
}

korzio

type Node struct {
  Token *token.Token
  Left  *Node
  Right *Node
}
// string representation
// 1 * 2 + 3 -> {+,{*,{1},{2}},{3}}
func (n *Node) ToString() string {
  res := "{" + n.Token.Literal
  if n.Left != nil {

korzio

tree := p.lexer.Tokens().
  Scan(func(_ context.Context, acc interface{}, elem interface{}) (interface{}, error) {
    it, isIterator := acc.(iterator)
    next := elem.(token.Token)
    if !isIterator || it.left == nil {
      // null denotation
      return nud(acc, next), nil
    }
    if it.operator != nil {
      var prevIt *iterator

korzio

func nud(acc interface{}, next token.Token) iterator {
  // Node{Token: token.Token{Type: token.PLUS, Literal: "+"}, Left: &Node{Token: token.Token{Type: token.INT, Literal: "2"}}}
  node := ast.Node{Token: &next}
  it := iterator{nud: &node}
  accIt, isIt := acc.(iterator)
  if isIt {
    // { , {... }
    node.Left = accIt.nud
    // save current stack
    it.stack = accIt.stack

korzio

package main

import (
  "fmt"
  "os"
  "os/user"
  "pizzascript/repl"
)

func main() {

korzio

package repl

import (
  "bufio"
  "fmt"
  "io"
  "pizzascript/eval"
  "pizzascript/lexer"
  "pizzascript/parser"
)

korzio

package token

type TokenType string
type Token struct {
  Type TokenType
  Literal string
}

const (
  // Literals

korzio

package lexer
import (
  "fmt"
  "strings"
  "pizzascript/token"
  "github.com/reactivex/rxgo/v2"
)

type Lexer struct {
  input       string