Merge pull request #5 from ChrisRackauckas-Claude/refactor-risch-method

Refactor to SciML-style method dispatch system

Author: ChrisRackauckas

src/SymbolicIntegration.jl

@@ -13,4 +13,10 @@ include("coupled_differential_systems.jl")
 include("algebraic_functions.jl")
 include("frontend.jl")
 
+# Add method dispatch system
+include("methods.jl")
+
+# Export method interface
+export AbstractIntegrationMethod, RischMethod
+
 end # module

src/frontend.jl

@@ -766,27 +766,27 @@ integrate(exp(x), x)  # exp(x)
 integrate(log(x), x)  # -x + x*log(x)
 ```
 """
-function integrate(f::Symbolics.Num, x::Symbolics.Num; kwargs...)
+function integrate_risch(f::Symbolics.Num, x::Symbolics.Num; kwargs...)
     # Extract SymbolicUtils expressions from Symbolics.Num wrappers
-    result_symbolic = integrate(f.val, x.val; kwargs...)
+    result_symbolic = integrate_risch(f.val, x.val; kwargs...)
     # Wrap result back in Symbolics.Num
     return Symbolics.Num(result_symbolic)
 end
 
 struct AlgebraicNumbersInvolved <: Exception end
 
-function integrate(f::SymbolicUtils.Add, x::SymbolicUtils.Symbolic; useQQBar::Bool=false,
+function integrate_risch(f::SymbolicUtils.Add, x::SymbolicUtils.Symbolic; useQQBar::Bool=false,
     catchNotImplementedError::Bool=true, catchAlgorithmFailedError::Bool=true)
     # For efficiency compute integral of sum as sum of integrals
     g = f.coeff*x
     for (h, c) in f.dict
-        g += c*integrate(h, x, useQQBar=useQQBar, catchNotImplementedError=catchNotImplementedError,
+        g += c*integrate_risch(h, x, useQQBar=useQQBar, catchNotImplementedError=catchNotImplementedError,
                          catchAlgorithmFailedError=catchAlgorithmFailedError)
     end
     g
 end
 
-function integrate(f::SymbolicUtils.Symbolic, x::SymbolicUtils.Symbolic; useQQBar::Bool=false,
+function integrate_risch(f::SymbolicUtils.Symbolic, x::SymbolicUtils.Symbolic; useQQBar::Bool=false,
     catchNotImplementedError::Bool=true, catchAlgorithmFailedError::Bool=true)
     try
         p, funs, vars, args = analyze_expr(f, x)

src/methods.jl

@@ -0,0 +1,89 @@
+# Method dispatch system for SymbolicIntegration.jl
+
+"""
+    AbstractIntegrationMethod
+
+Abstract supertype for all symbolic integration methods.
+"""
+abstract type AbstractIntegrationMethod end
+
+"""
+    RischMethod <: AbstractIntegrationMethod
+
+Risch algorithm for symbolic integration of elementary functions.
+
+# Fields
+- `use_algebraic_closure::Bool`: Whether to use algebraic closure for complex roots (default: true)
+- `catch_errors::Bool`: Whether to catch and handle algorithm errors gracefully (default: true)
+"""
+struct RischMethod <: AbstractIntegrationMethod
+    use_algebraic_closure::Bool
+    catch_errors::Bool
+    
+    function RischMethod(; use_algebraic_closure::Bool=true, catch_errors::Bool=true)
+        new(use_algebraic_closure, catch_errors)
+    end
+end
+
+"""
+    integrate(f, x, method::AbstractIntegrationMethod=RischMethod(); kwargs...)
+
+Compute the symbolic integral of expression `f` with respect to variable `x` 
+using the specified integration method.
+
+# Arguments
+- `f`: Symbolic expression to integrate (Symbolics.Num)
+- `x`: Integration variable (Symbolics.Num)  
+- `method`: Integration method to use (AbstractIntegrationMethod, default: RischMethod())
+
+# Keyword Arguments
+- Method-specific keyword arguments are passed to the method implementation
+
+# Returns
+- Symbolic expression representing the antiderivative (Symbolics.Num)
+
+# Examples
+```julia
+using SymbolicIntegration, Symbolics
+@variables x
+
+# Using default Risch method
+integrate(x^2, x)  # (1//3)*(x^3)
+
+# Explicit method with options
+integrate(1/(x^2 + 1), x, RischMethod(use_algebraic_closure=true))  # atan(x)
+
+# Method configuration
+risch = RischMethod(use_algebraic_closure=false, catch_errors=true)
+integrate(exp(x), x, risch)  # exp(x)
+```
+"""
+function integrate(f::Symbolics.Num, x::Symbolics.Num, method::RischMethod; kwargs...)
+    # Call renamed Risch function with method options
+    return integrate_risch(f, x;
+        useQQBar=method.use_algebraic_closure,
+        catchNotImplementedError=method.catch_errors,
+        catchAlgorithmFailedError=method.catch_errors,
+        kwargs...)
+end
+
+# Main integrate function - dispatches to RischMethod by default
+function integrate(f::Symbolics.Num, x::Symbolics.Num; kwargs...)
+    return integrate_risch(f, x; kwargs...)
+end
+
+"""
+    method_supports_rational(method::RischMethod)
+
+Check if the integration method supports rational function integration.
+Returns `true` for RischMethod.
+"""
+method_supports_rational(method::RischMethod) = true
+
+"""
+    method_supports_transcendental(method::RischMethod)
+
+Check if the integration method supports transcendental function integration.
+Returns `true` for RischMethod.
+"""
+method_supports_transcendental(method::RischMethod) = true