github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6: Option

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify github.com/ianlancetaylor/demangle.Option in pkg:golang/github.com/ianlancetaylor/demangle@v0.0.0-20181102032728-5e5cf60278f6
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/ianlancetaylor/demangle@v0.0.0-20181102032728-5e5cf60278f6
Demonstrate these symbols/APIs:
  - github.com/ianlancetaylor/demangle.Option

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:0d6bbda83bd61f3762f9e23fad0baa5608e55a5abffcfd22f084476acfa7e5c6","contract":["demangle.NoParams option disables demangling of function parameters in demangle.ToString","demangle.NoTemplateParams option disables demangling of template parameters in demangle.ToString","demangle.NoClones option disables inclusion of clone suffixes in demangle.ToString","demangle.Verbose option enables expansion of standard substitutions in demangle.ToString","demangle.Option values can be combined to strip both template parameters and function parameters","demangle.ToString returns ErrNotMangledName when input is not a C++ mangled name"],"goal":"verify github.com/ianlancetaylor/demangle.Option in pkg:golang/github.com/ianlancetaylor/demangle@v0.0.0-20181102032728-5e5cf60278f6","kind":"HOW","packages":["pkg:golang/github.com/ianlancetaylor/demangle@v0.0.0-20181102032728-5e5cf60278f6"],"schemaVersion":1,"symbols":["github.com/ianlancetaylor/demangle.Option"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","compiler":"go","compilerVersion":"1.26.6","distro":"ubuntu","ecosystem":"golang","language":"go","languageVersion":"1.26.6","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","packageManagerVersion":"1.26.6","runtime":"go","runtimeVersion":"1.26.6","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/ianlancetaylor/demangle@v0.0.0-20181102032728-5e5cf60278f6"],"schemaVersion":1,"subject":"pkg:golang/github.com/ianlancetaylor/demangle@v0.0.0-20181102032728-5e5cf60278f6","symbols":["github.com/ianlancetaylor/demangle.Option"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6

github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6 h1:UDMh68UUwekSh5iP2OMhRRZJiiBccgV7axzUG8vi56c=
github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=

package main

import (
	"fmt"
	"os"

	"github.com/ianlancetaylor/demangle"
)

func main() {
	// 1. Basic demangling with default options
	mangledFunc := "_Z3fooi"
	demangled, err := demangle.ToString(mangledFunc)
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to demangle: %v\n", err)
		os.Exit(1)
	}
	fmt.Printf("Default: %s -> %s\n", mangledFunc, demangled)

	// 2. Using demangle.NoParams to omit function parameters
	demangledNoParams, err := demangle.ToString(mangledFunc, demangle.NoParams)
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to demangle with NoParams: %v\n", err)
		os.Exit(1)
	}
	fmt.Printf("NoParams: %s -> %s\n", mangledFunc, demangledNoParams)

	// 3. Using demangle.NoTemplateParams to omit template arguments
	mangledTemplate := "_Z3barIiEvT_"
	demangledNoTemplate, err := demangle.ToString(mangledTemplate, demangle.NoTemplateParams)
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to demangle with NoTemplateParams: %v\n", err)
		os.Exit(1)
	}
	fmt.Printf("NoTemplateParams: %s -> %s\n", mangledTemplate, demangledNoTemplate)

	// 4. Using demangle.NoClones to omit clone suffixes
	mangledClone := "_Z3fooi.clone.0"
	demangledNoClones, err := demangle.ToString(mangledClone, demangle.NoClones)
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to demangle with NoClones: %v\n", err)
		os.Exit(1)
	}
	fmt.Printf("NoClones: %s -> %s\n", mangledClone, demangledNoClones)

	// 5. Using demangle.Verbose to expand standard substitutions
	mangledString := "_Z3fooSs"
	demangledVerbose, err := demangle.ToString(mangledString, demangle.Verbose)
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to demangle with Verbose: %v\n", err)
		os.Exit(1)
	}
	fmt.Printf("Verbose: %s -> %s\n", mangledString, demangledVerbose)

	// 6. Combining options
	combined, err := demangle.ToString(mangledTemplate, demangle.NoParams, demangle.NoTemplateParams)
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to demangle with combined options: %v\n", err)
		os.Exit(1)
	}
	fmt.Printf("Combined: %s -> %s\n", mangledTemplate, combined)
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/ianlancetaylor/demangle.Option in pkg:golang/github.com/ianlancetaylor/demangle@v0.0.0-20181102032728-5e5cf60278f6",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/ianlancetaylor/demangle@v0.0.0-20181102032728-5e5cf60278f6"
  ],
  "symbols": [
    "github.com/ianlancetaylor/demangle.Option"
  ]
}

package main

import (
	"fmt"
	"os"

	"github.com/ianlancetaylor/demangle"
)

func main() {
	// Assertion 1: demangle.NoParams option disables demangling of function parameters in demangle.ToString
	{
		res, err := demangle.ToString("_Z3fooi", demangle.NoParams)
		if err != nil {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: %v\n", err)
			os.Exit(1)
		}
		if res != "foo" {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: expected 'foo', got %q\n", res)
			os.Exit(1)
		}
	}

	// Assertion 2: demangle.NoTemplateParams option disables demangling of template parameters in demangle.ToString
	{
		res, err := demangle.ToString("_Z3barIiEvT_", demangle.NoTemplateParams)
		if err != nil {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: %v\n", err)
			os.Exit(1)
		}
		if res != "void bar(int)" {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: expected 'void bar(int)', got %q\n", res)
			os.Exit(1)
		}
	}

	// Assertion 3: demangle.NoClones option disables inclusion of clone suffixes in demangle.ToString
	{
		res, err := demangle.ToString("_Z3fooi.clone.0", demangle.NoClones)
		if err != nil {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: %v\n", err)
			os.Exit(1)
		}
		if res != "foo(int)" {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: expected 'foo(int)', got %q\n", res)
			os.Exit(1)
		}
	}

	// Assertion 4: demangle.Verbose option enables expansion of standard substitutions in demangle.ToString
	{
		res, err := demangle.ToString("_Z3fooSs", demangle.Verbose)
		if err != nil {
			fmt.Fprintf(os.Stderr, "assertion 4 failed: %v\n", err)
			os.Exit(1)
		}
		expected := "foo(std::basic_string<char, std::char_traits<char>, std::allocator<char> >)"
		if res != expected {
			fmt.Fprintf(os.Stderr, "assertion 4 failed: expected %q, got %q\n", expected, res)
			os.Exit(1)
		}
	}

	// Assertion 5: demangle.Option values can be combined to strip both template parameters and function parameters
	{
		res, err := demangle.ToString("_Z3barIiEvT_", demangle.NoParams, demangle.NoTemplateParams)
		if err != nil {
			fmt.Fprintf(os.Stderr, "assertion 5 failed: %v\n", err)
			os.Exit(1)
		}
		if res != "bar" {
			fmt.Fprintf(os.Stderr, "assertion 5 failed: expected 'bar', got %q\n", res)
			os.Exit(1)
		}
	}

	// Assertion 6: demangle.ToString returns ErrNotMangledName when input is not a C++ mangled name
	{
		_, err := demangle.ToString("invalid_mangled_symbol")
		if err != demangle.ErrNotMangledName {
			fmt.Fprintf(os.Stderr, "assertion 6 failed: expected ErrNotMangledName, got %v\n", err)
			os.Exit(1)
		}
	}

	fmt.Println("All demangle.Option contract assertions passed successfully.")
}