Run in Eval mode

Use eval command to evaluate code snippets from CLI:

$ calcit eval 'echo |demo'
1
took 0.07ms: nil

$ calcit eval 'echo "|spaced string demo"'
spaced string demo
took 0.074ms: nil

Multi-line Code

You can run multiple expressions:

calcit eval '
-> (range 10)
  map $ fn (x)
    * x x
'
# Output: calcit version: 0.5.25
# took 0.199ms: ([] 0 1 4 9 16 25 36 49 64 81)

Working with Context Files

Eval can access definitions from a loaded program:

# Load from specific file and eval with its context
calcit demos/calcit.cirru eval 'range 3'
# Output: ([] 0 1 2)

# Use let bindings
calcit demos/calcit.cirru eval 'let ((x 1)) (+ x 2)'
# Output: 3

You can load external modules with repeatable --dep options:

calcit demos/calcit.cirru eval --dep ~/.config/calcit/modules/respo.calcit/ -- 'ns app.demo $ :require respo.util.detect :refer $ element?\n\nelement? nil'

If the first expression in a snippet is ns, its :require rules are merged into runtime ns app.main, so imported symbols can be used in the same snippet.

Type Checking in Eval

Type annotations and static checks work in eval mode:

# Type mismatch will cause error
calcit demos/calcit.cirru eval 'let ((x 1)) (assert-type x :string) x'
# Error: Type mismatch...

# Correct type passes
calcit demos/calcit.cirru eval 'let ((x 1)) (assert-type x :number) x'
# Output: 1

Common Patterns

Quick Calculations

calcit eval '+ 1 2 3 4'
# Output: 10

calcit eval 'apply * $ range 1 6'
# Output: 120  ; factorial of 5

Testing Expressions

calcit eval '&list:nth ([] :a :b :c) 1'
# Output: :b

calcit eval '&map:get ({} (:x 1) (:y 2)) :x'
# Output: 1

Exploring Functions

# Check function signature
calcit eval 'type-of range'
# Output: :fn

# Test with sample data
calcit eval '-> (range 5) (map inc) (filter (fn (x) (> x 2)))'
# Output: ([] 3 4 5)

Important Notes

Syntax Considerations

No extra brackets: Cirru syntax doesn't need outer parentheses at top level
- ✅ calcit eval 'range 3'
- ❌ calcit eval '(range 3)' (adds extra nesting)
Let bindings: Use paired list format ((name value))
- ✅ let ((x 1)) x
- ❌ let (x 1) x (triggers "expects pairs in list for let" error)

Error Diagnostics

Type warnings cause eval to fail (intentional safety feature)
Check .calcit-error.cirru for complete stack traces
Use calcit cirru parse-oneliner to debug parse issues

Query Examples

Use calcit query examples to see usage examples:

calcit demos/calcit.cirru query examples calcit.core/let
calcit demos/calcit.cirru query examples calcit.core/defn

For markdown snippet validation (docs check-md), see CLI Options.

Calcit Guide