Elex.Validator (Elex v0.2.1)

Validates a parsed expression AST for type correctness.

Checks that operators are applied to compatible types, variables exist in the context, and function calls match registered signatures. Used by Elex.Parser during parsing and available for direct AST validation.

Examples

context = Elex.new_context() |> Elex.add_variable("x", 10)
{:ok, ast, _} = Elex.Parser.parse("x + 5", context, validate: false)
Elex.Validator.validate(ast, context)
#=> {:ok, :decimal}

Summary

Functions

validate(ast, ctx)

Validates an expression AST against a context.

Functions

validate(ast, ctx)

@spec validate(term(), Elex.Context.t()) :: {:ok, atom()} | {:error, String.t()}

Validates an expression AST against a context.

Parameters

ast - A parsed AST node from Elex.Parser
ctx - A Elex.Context with variable types and functions

Returns

{:ok, type} - The expression's result type (:decimal, :boolean, :string, or nil)
{:error, reason} - A human-readable validation error

Examples

context = Elex.new_context() |> Elex.add_variable("x", 10)
{:ok, ast, _} = Elex.Parser.parse("x > 0", context, validate: false)
Elex.Validator.validate(ast, context)
#=> {:ok, :boolean}