4D Syntax Checker

Compile a 4D project to check for syntax errors and type mismatches.

Prerequisites

Uses the 4d-run skill to execute the compilation method. Ensure tool4d is available:

Install 4D-Analyzer extension in VS Code/Antigravity, OR
Set TOOL4D environment variable to point to tool4d executable

The _compile Method

Compilation requires a _compile method in the project. If not present, copy assets/_compile.4dm to Project/Sources/Methods/_compile.4dm.

Compilation Output

Success

{"success":true,"errors":[]}

Errors

{
  "success": false,
  "errors": [
    {
      "message": "Syntax error",
      "isError": true,
      "code": {
        "type": "classFunction",
        "className": "MyClass",
        "functionName": "myMethod",
        "path": "[class]/MyClass/myMethod",
        "file": "[object File]"
      },
      "line": 10,
      "lineInFile": 42
    }
  ]
}

Error Properties

message: Error description
isError: true for errors, false for warnings
code.type: "projectMethod", "classFunction", etc.
code.className: Class name (for class methods)
code.functionName: Function name
line: Line within the function
lineInFile: Absolute line in the file

Workflow

Check for _compile method: Look in Project/Sources/Methods/_compile.4dm
Create if missing: Write the _compile method using the template above
Find tool4d: Use 4d-run skill to locate tool4d
Run compilation: Execute _compile method with --dataless
Parse results: Extract JSON from ALERT output

Running Compilation

"<tool4d_path>" --project="<project_path>" --startup-method=_compile --dataless 2>&1

Output format:

{"success":true,"errors":[]}

The JSON is output directly to system standard output via LOG EVENT.

Common Compilation Errors

Error	Cause	Fix
"Syntax error"	Invalid 4D syntax	Check line for typos
"Object syntax is not valid"	Invalid object property access	Use `[index]` for 4D.Blob properties
"Cannot make an assignment with those types"	Type mismatch	Check variable types
"Undeclared property 'X' used"	Missing property declaration	Add `property X : Type` to class
"The variable $X has not been explicitly declared"	Missing var declaration	Add `var $X : Type`
"signed integer overflow handling differs"	PCH cache issue	Not a code error, can ignore

Integration Example

# Find tool4d
TOOL4D=$(python3 ".claude/skills/4d-run/scripts/find_tool4d.py")

# Run compilation and parse JSON result
OUTPUT=$("$TOOL4D" --project="/path/to/Project/MyProject.4DProject" --startup-method=_compile --dataless 2>&1)

# The JSON is output directly via LOG EVENT
echo "$OUTPUT" | jq .

4d-check-syntax

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