I have 17 (len(inputStartSlice)) slices of indexes that'll make a series of string slices. Currently, my code is only producing a single slice of strings (a single input, as I hardcode the positions, seen below) when I have 17 that I need to loop through into a single, 2D array of strings.

var inputSlices []string
var inputStartSlice []int
var inputEndSlice []int
var input []string
var inputs [][]string


for v, line := range inputSlices {
  if strings.Contains(line, "{") {
    inputStartSlice = append(inputStartSlice, v)
  }
  if strings.Contains(line, "}") {
    inputEndSlice = append(inputEndSlice, v 1)
  }
}

input = inputSlice[inputStartSlice[3]:inputEndSlice[3]]

inputs = append(inputs, input)
fmt.Println(inouts)

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Is there a better way to go about doing this? I'm sure there is, if anybody can help me understand better approaches or elaborate on how I can solve where I'm currently stuck..

CodePudding user response：

I've rewritten your code in a more idiomatic way. Check the comments for explanations. This code works, but as mpx suggested, for processing any custom format you have to write a tokenizer and a lexer to be sure that everything is parsed correctly and every possible syntax error is handled.

package main

import (
    "fmt"
    "log"
    "strings"

    "golang.org/x/exp/slices"
)

func main() {

    var codeSlices = []string{
        "# INPUTS",
        "",
        "input CreateUserInput {",
        "  username: String!",
        "  email: String!",
        "  password: String!",
        "}",
        "",
        "input AuthUserInput {",
        "  user: String!",
        "  password: String!",
        "  code: String",
        "}",
        "",
        "input RefreshTokensInput{",
        "  refreshToken: String!",
        "}",
        "",
        "input VerifyEmailInput {",
        "  token: String!",
        "}",
        "",
        "# OBJECTS",
        "",
    }

    //Check for boundaries
    inputStart := slices.Index(codeSlices, "# INPUTS") //Use built-in functions for the search
    if inputStart == -1 {
        log.Fatal("# INPUTS not found")
    }

    objectStart := slices.Index(codeSlices, "# OBJECTS")
    if objectStart == -1 {
        log.Fatal("# OBJECTS not found")
    }

    var inputStartSlice []int
    var inputEndSlice []int

    //No need to copy your codeSlices to inputSlice, just go from inputs to objects, this is faster.
    for i := inputStart   2; i < objectStart-1; i   {
        if strings.HasSuffix(codeSlices[i], "{") { //HasSuffix is better here, since the { must be the last char
            inputStartSlice = append(inputStartSlice, i)
            continue //No need to check for closing bracket, so we can continue to skip another check
        }
        if codeSlices[i] == "}" { //Direct equality is faster than Contains
            inputEndSlice = append(inputEndSlice, i 1)
        }
    }

    //Check to every open bracket have a closing one
    if len(inputStartSlice) != len(inputEndSlice) {
        log.Fatal("len(inputStartSlice) != len(inputEndSlice)")
    }

    //Concating final results
    var inputs [][]string
    for i := range inputStartSlice {
        inputs = append(inputs, codeSlices[inputStartSlice[i]:inputEndSlice[i]])
    }

    fmt.Println(inputs)
}

CodePudding user response：

You can achieve the same without using extra variables

package main

import (
    "fmt"
    "log"
    "strings"

    "golang.org/x/exp/slices"
)

func main() {

    var codeSlices = []string{
        "# INPUTS",
        "",
        "input CreateUserInput {",
        "  username: String!",
        "  email: String!",
        "  password: String!",
        "}",
        "",
        "input AuthUserInput {",
        "  user: String!",
        "  password: String!",
        "  code: String",
        "}",
        "",
        "input RefreshTokensInput{",
        "  refreshToken: String!",
        "}",
        "",
        "input VerifyEmailInput {",
        "  token: String!",
        "}",
        "",
        "# OBJECTS",
        "",
    }

    //Check for boundaries
    inputStart := slices.Index(codeSlices, "# INPUTS") //Use built-in functions for the search
    if inputStart == -1 {
        log.Fatal("# INPUTS not found")
    }

    objectStart := slices.Index(codeSlices, "# OBJECTS")
    if objectStart == -1 {
        log.Fatal("# OBJECTS not found")
    }

    inputStart = 0
    var inputs [][]string
    for i := inputStart   2; i < objectStart-1; i   {
        if idx := strings.Index(codeSlices[i], "{"); idx > 0 {
            inputStart = i
            continue
        }
        if idx := slices.Index(codeSlices[inputStart:], "}"); inputStart > 0 {
            inputs = append(inputs, codeSlices[inputStart:i idx])
            inputStart = 0
        }
    }

    if inputStart > 0 {
        log.Fatal("Mismatch inputs")
    }

    fmt.Printf("%#v\n", inputs)
}

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