km hal

Computes Halstead complexity metrics per file by extracting operators and operands from source code.

km hal [path]

Metrics

Symbol	Metric	Formula	Description
n1	Distinct operators	—	Unique operators in the code
n2	Distinct operands	—	Unique operands in the code
N1	Total operators	—	Total operator occurrences
N2	Total operands	—	Total operand occurrences
n	Vocabulary	n1 + n2	Size of the “alphabet” used
N	Length	N1 + N2	Total number of tokens
V	Volume	N * log2(n)	Size of the implementation
D	Difficulty	(n1/2) * (N2/n2)	Error proneness
E	Effort	D * V	Mental effort to develop
B	Bugs	V / 3000	Estimated delivered bugs
T	Time	E / 18 seconds	Estimated development time

Higher effort, volume, and bugs indicate more complex and error-prone code.

Options:

Flag	Description
--format {table,json,short,terse}	Output format (default: table)
--include-tests	Include test files in analysis (excluded by default)
--top N	Show only the top N files (default: 20)
--sort-by METRIC	Sort by effort, volume, or bugs (default: effort)

Example output:

Halstead Complexity Metrics
──────────────────────────────────────────────────────────────────────────────
 File                      n1   n2    N1    N2    Volume     Effort   Bugs
──────────────────────────────────────────────────────────────────────────────
 src/loc/counter.rs       139  116  3130  1169   34367.7   24070888  11.46
 src/main.rs               37   43   520   185    4457.0     354743   1.49
──────────────────────────────────────────────────────────────────────────────
 Total (2 files)                     3650  1354   38824.7   24425631  12.95

Supported languages

Rust, Python, JavaScript, TypeScript, Go, C, C++, C#, Java, Objective-C, PHP, Dart, Ruby, Kotlin, Swift, Shell (Bash/Zsh).