Lesson: Unclosed Parentheses In `If()` Chains Cause Silent Failure¶

The Problem¶

A widget function with multiple chained If() calls:

Function XWeatherIcon() {
  Return(
    If(XWeatherCode = 0, "weather-clear-symbolic",
    If(XWeatherCode = 1, "weather-few-clouds-symbolic",
    ...
    If(XWeatherCode = 25, "weather-snow-symbolic",
      "weather-clear-symbolic")))))))     # ← 8 closing parens, need 9
}

The outer If() call is never closed. The function returns without a value, and the widget shows nothing.

Root Cause¶

When nesting If() calls, each If( needs one closing ) — plus one for the outer Return(. In weather.widget, both XWeatherIcon() and XWeatherDesc() have 9 If() calls but only 8 closing parentheses on the last line.

This is extremely hard to spot visually because the closing parens are all on one line: )))))))). Counting them is error-prone.

# Line 22 in weather.widget — 8 parens for 9 If() calls
      "weather-clear-symbolic"))))))))
#                                12345678 (X) wrong

The Fix¶

Count parentheses explicitly. For 9 If() calls, you need 9 closing parens:

# Line 22 — 9 parens for 9 If() calls
      "weather-clear-symbolic")))))))))
#                                123456789 (OK) correct

Better: format nested If() with one paren per line to make counting obvious:

Function XWeatherIcon() {
  Return(
    If(XWeatherCode = 0, "weather-clear-symbolic",
    If(XWeatherCode = 1, "weather-few-clouds-symbolic",
    ...
    If(XWeatherCode = 25, "weather-snow-symbolic",
      "weather-clear-symbolic"
    ))))))
  )
}

This makes it clear that each If( has its own ) on the same indentation level.

Verification¶

# Count opening vs closing parens in a widget file
opens=$(grep -o 'If(' weather.widget | wc -l)
closes=$(grep -o ')' weather.widget | wc -l)
# Each If( needs one ), plus Return( needs one ), plus Function block {}
# Expected: opens + 2 (for Return + Function block) = total closes
echo "If(...) opens: $opens, total closes: $closes"

Where This Applies¶

weather.widget:12-23 — XWeatherIcon() function
weather.widget:25-36 — XWeatherDesc() function

Pattern To Remember¶

One If( needs exactly one ). When nesting N levels deep, count N closing parens. Put them one-per-line to verify.

Lesson: Unclosed Parentheses In If() Chains Cause Silent Failure¶