Errors & Debugging

Understanding JSSON's friendly error messages and how to debug common issues. Meet the goblins, wizards, and gremlins!

JSSON has a unique approach to errors — instead of cryptic messages, you get help from friendly (well, mostly friendly) creatures! 🧙‍♂️👺

The Error Squad

JSSON's error system has three characters, each responsible for a different phase:

Character	Phase	What They Check
Lex Goblin 👺	Lexing	Invalid characters, unterminated strings
Parse Wizard 🧙‍♂️	Parsing	Syntax errors, unexpected tokens
Transpiler Gremlin 👹	Transpilation	Type errors, undefined references

Lex Goblin Errors 👺

The Lex Goblin catches errors during tokenization — when JSSON reads your file character by character.

Illegal Character

Error:

Lex goblin: 1:5 — Illegal character: '@'

What it means: You used a character that JSSON doesn't recognize.

Example:

name = João@Silva  // ❌ @ is not allowed without quotes

Fix:

name = "João@Silva"  // ✅ Use quotes for special characters

Unterminated String

Error:

Lex goblin: 2:10 — Unterminated string

What it means: You started a string with " but never closed it.

Example:

name = "João
age = 25  // ❌ Missing closing quote

Fix:

name = "João"  // ✅ Close the string
age = 25

Parse Wizard Errors 🧙‍♂️

The Parse Wizard catches syntax errors — when your JSSON structure is invalid.

Unexpected Token

Error:

Parse wizard: 3:8 — Unexpected token: expected '=', got '{'

What it means: The parser expected one thing but found another.

Example:

user
{  // ❌ Missing assignment operator
  name = João
}

Fix:

user {  // ✅ Add the assignment (or just put { on same line)
  name = João
}

Missing Closing Brace

Error:

Parse wizard: EOF — Expected '}', got EOF

What it means: You opened a { but never closed it.

Example:

user {
  name = João
  age = 25
// ❌ Missing }

Fix:

user {
  name = João
  age = 25
}  // ✅ Close the object

Invalid Array Syntax

Error:

Parse wizard: 2:15 — Expected ']', got ','

What it means: Array syntax is incorrect.

Example:

colors = [ red, blue, green,, ]  // ❌ Double comma

Fix:

colors = [ red, blue, green ]  // ✅ Remove extra comma

Template Errors

Error:

Parse wizard: 3:5 — Template expects 3 fields, got 2

What it means: A template row doesn't match the template definition.

Example:

users [
  template { name, age, email }
  João, 25  // ❌ Missing email
]

Fix:

users [
  template { name, age, email }
  João, 25, "joao@test.com"  // ✅ All 3 fields
]

Transpiler Gremlin Errors 👹

The Transpiler Gremlin catches semantic errors — when your JSSON is syntactically correct but logically wrong.

Undefined Reference

Error:

Transpiler gremlin: 5:12 — Undefined reference: 'config.port'

What it means: You're trying to access a property that doesn't exist.

Example:

server {
  host = localhost
}

url = server.host + ":" + config.port // ❌ config doesn't exist

Fix:

server {
  host = localhost
  port = 8080  // ✅ Define port
}

url = server.host + ":" + server.port // ✅ Use server.port

Type Mismatch

Error:

Transpiler gremlin: 3:10 — Cannot perform operation '+' on boolean and string

What it means: You're trying to combine incompatible types.

Example:

active = true
message = "Status: " + active  // ❌ Can't add boolean to string

Fix:

active = "true"  // ✅ Make it a string
message = "Status: " + active

Common Mistakes & Solutions

1. Forgetting Quotes

Problem:

title = Software Engineer  // ❌ Space without quotes

Solution:

title = "Software Engineer"  // ✅ Use quotes for spaces

2. Using JSON Syntax

Problem:

user {
  "name": "João",  // ❌ JSON syntax
  "age": 25,
}

Solution:

user {
  name = João  // ✅ JSSON syntax
  age = 25
}

3. Missing Commas in Arrays

Problem:

colors = [ red blue green ]  // ❌ Missing commas

Solution:

colors = [ red, blue, green ]  // ✅ Add commas

4. Trailing Commas

Problem:

colors = [ red, blue, green, ]  // ❌ Trailing comma

Solution:

colors = [ red, blue, green ]  // ✅ Remove trailing comma

5. Wrong File Extension

Problem:

jsson -i config.json  # ❌ Wrong extension

Solution:

jsson -i config.jsson  # ✅ Use .jsson extension

Debugging Tips

1. Check Line Numbers

Error messages always include line and column numbers:

Parse wizard: 15:8 — Unexpected token
              ↑  ↑
            line column

Go to that exact location in your file!

2. Look for Unclosed Brackets

If you see EOF (End Of File) errors, you probably forgot to close something:

user {
  name = João
  config {
    theme = dark
  // ❌ Missing } for config
// ❌ Missing } for user

Tip: Use an editor with bracket matching!

3. Validate Incrementally

Build your JSSON file step by step:

# Start simple
echo 'name = João' > test.jsson
jsson -i test.jsson  # ✅ Works

# Add more
echo 'age = 25' >> test.jsson
jsson -i test.jsson  # ✅ Still works

# Keep adding until you find the problem

4. Use Comments to Debug

Comment out sections to isolate the problem:

user {
  name = João
  age = 25
}

// database {
//   host = localhost
//   port = 5432
// }

api {
  url = "https://api.example.com"
}

5. Check Your Quotes

Mixed quotes can cause issues:

name = "João'  // ❌ Mismatched quotes
name = "João"  // ✅ Matching quotes

Error Message Format

All JSSON errors follow this format:

[Character]: [Location] — [Message]

Example:

Lex goblin: config.jsson:15:8 — Illegal character: '@'
↑           ↑                   ↑
Character   Location            Message

Location formats:

15:8 — Line 15, column 8
config.jsson:15:8 — File, line, column
EOF — End of file

Getting Help

If you're stuck:

Read the error message carefully — it usually tells you exactly what's wrong
Check the line number — go to that exact location
Look at examples in the Syntax Reference
Compare with working code — what's different?
Ask for help on GitHub Issues

What's Next?

Now that you know how to debug JSSON:

Syntax Reference — Complete syntax guide
Templates Guide — Master template arrays
CLI Guide — Command-line options

Don't fear the errors — the goblins, wizards, and gremlins are here to help! 🧙‍♂️👺👹

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