Class: OllamaAgent::Tools::SafeCalculator

Inherits:
Base
  • Object
show all
Defined in:
lib/ollama_agent/tools/safe_calculator.rb

Overview

Safe arithmetic evaluator using the Shunting-yard algorithm.

Supports +, -, *, /, ** and parentheses on numeric literals. Does NOT use eval — the expression is parsed into tokens, converted to reverse-Polish notation, and evaluated on a stack.

Constant Summary collapse

OPERATORS =

Operator table: precedence, associativity, arity. Unary +/- are prefixed with ‘u’ to distinguish from binary operators.

{
  "+" => { precedence: 1, assoc: :left,  arity: 2 },
  "-" => { precedence: 1, assoc: :left,  arity: 2 },
  "*" => { precedence: 2, assoc: :left,  arity: 2 },
  "/" => { precedence: 2, assoc: :left,  arity: 2 },
  "**" => { precedence: 3, assoc: :right, arity: 2 },
  "u+" => { precedence: 4, assoc: :right, arity: 1 },
  "u-" => { precedence: 4, assoc: :right, arity: 1 }
}.freeze

Constants inherited from Base

Base::RISK_LEVELS

Instance Attribute Summary

Attributes inherited from Base

#description, #input_schema, #name, #output_schema, #requires_approval, #risk_level

Instance Method Summary collapse

Methods inherited from Base

#initialize, #to_anthropic_schema, #to_ollama_schema, #to_s, tool_description, tool_name, tool_output_schema, tool_requires_approval, tool_risk, tool_schema

Constructor Details

This class inherits a constructor from OllamaAgent::Tools::Base

Instance Method Details

#call(args, context: {}) ⇒ Object 



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# File 'lib/ollama_agent/tools/safe_calculator.rb', line 42

def call(args, context: {})
  expression = args["expression"].to_s
  tokens = tokenize(expression)
  rpn    = to_rpn(tokens)
  value  = eval_rpn(rpn)
  value.finite? ? value.to_s : "Error: result is non-finite (division by zero?)"
rescue StandardError => e
  "Error: #{e.message}"
end