Will Hawkins
129 lines
3.0 KiB
Swift
129 lines
3.0 KiB
Swift
// p4rse, Copyright 2026, Will Hawkins
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//
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// This file is part of p4rse.
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//
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// This file is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program. If not, see <https://www.gnu.org/licenses/>.
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open class ProgramExecution: CustomStringConvertible {
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public var scopes: Scopes = Scopes()
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var error: Error?
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public init() {}
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open var description: String {
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return "Runtime:\nScopes: \(scopes)"
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}
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public func hasError() -> Bool {
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return self.error != nil
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}
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public func getError() -> Error? {
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return self.error
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}
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public func setError(error: Error) -> ProgramExecution {
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let npe = self
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npe.error = error
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return npe
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}
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}
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public struct Scope: CustomStringConvertible{
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var variables: [Variable] = Array()
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public init() {}
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public var description: String {
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var result = String()
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for v in variables {
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result += "\(v)\n"
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}
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return result
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}
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public var count: Int {
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get {
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variables.count
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}
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}
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public func lookup(identifier: Identifier) -> Variable? {
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for v in variables {
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if v == identifier {
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return v
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}
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}
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return .none
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}
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public mutating func declare(variable: Variable) -> Scope {
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var s = self
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s.variables.append(variable)
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return s
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}
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}
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public struct Scopes: CustomStringConvertible {
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var scopes: [Scope] = Array()
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public init() {}
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public mutating func enter() {
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scopes.append(Scope())
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}
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public mutating func exit() {
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let _ = scopes.popLast()
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}
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public var description: String {
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var result = String()
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for s in scopes {
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result += "Scope:\n\(s)\n"
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}
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return result
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}
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public var current: Scope? {
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get {
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scopes.last
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}
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}
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public func declare(variable: Variable) -> Scopes {
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var s = self
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if var scope = s.scopes.popLast() {
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s.scopes.append(scope.declare(variable: variable))
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}
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return s
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}
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public func evaluate(identifier: Identifier) -> Result<P4Value> {
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for scope in scopes {
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if let vari = scope.lookup(identifier: identifier) {
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return .Ok(vari.value)
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}
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}
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return .Error(Error(withMessage: "Cannot find \(identifier) in scope."))
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}
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public var count: Int {
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get {
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scopes.count
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}
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}
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}
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