You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
BashOOP/oop.sh

201 lines
7.8 KiB

#
# BashOOP - Simple OOP implementation for bash.
# Copyright (C) 2022 Ad5001 <mail@ad5001.eu>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# This file contains all functions required to create a namespace.
# Internal variables are marked with a beginning underscore, like in most other languages.
# Signatures are a list of arguments.. Those within <> are mandatory, the ones within [] are optional.
# Namespace related variables.
_namespace=""
_namespacePath=$(realpath $(dirname ${BASH_SOURCE[0]}))
# Allows the creation of temporary, unique names for variables so that
# when declaring a new object with the same variable name, the previous one wouldn't be overwritten with
# the new object.
# However, this disallows the syntax that doesn't use $ at first, which makes the documentation clearer.
_counter=0
# This dictionnary saves all classes for each namespace so they can be retreived and aliased.
declare -Ag _namespacesClasses
# This dictionnary links all files for static namespaces.
declare -Ag _namespacesStaticClasses
# Declares the current namespace.
# Signature: ([string namespaceName]) -> void
namespace() {
_namespace=$1;
}
# Imports a namespace into the current shell.
# It saves the path of the file so that relative paths can be
# properly resolved.
# For example, if the object Object exists within namespace Example, it
# will be accessible with "Example.Object".
# Signature: (<string namespaceFile>) -> void
importNamespace() {
namespaceFile=$1
# Save the path in order to get the absolute path of the file.
_namespacePath=$(realpath $(dirname $namespaceFile))
. $namespaceFile
}
# Aliases the classes in global namespace.
# For example, if the object Object exists within namespace Example, it
# will be accessible with "Example.Object" and "Object".
# Signature: (<string namespaceName>) -> void
using() {
namespaceName=$1
# Import static classes
if [ "${_namespacesStaticClasses[$namespaceName]}" != "" ]; then
oldNamespace=_namespace
namespace # Reset namespace
# Split all
staticClasses=$(echo "${_namespacesStaticClasses[$namespaceName]}" | tr ";" "\n")
for cl in $staticClasses; do
parts=$(echo "$cl" | tr ":" "\n")
static_class ${parts[0]} ${parts[1]}
done
namespace $oldNamespace
fi
# Import static classes
if [ "${_namespacesClasses[$namespaceName]}" != "" ]; then
classes=$(echo "${_namespacesClasses[$namespaceName]}" | tr ";" "\n")
for type in $classes; do
eval "$type() { $namespaceName.$type \$@; }"
done
fi
}
# Creates a "property holder" based on a name.
# A "property holder" is a dictionnary maintaining the values of properties for a specific variable.
# One is created each time an object is declared, but this function can also be used for namespaces to have global
# properties.
# Signature: (<string name>) -> void
createPropertyHolder() {
name=$1
eval "declare -Ag _${name}_properties"
}
# Creates an object instance of `type` in variable `variableName`.
# Signature: (<string type>, <string associatedFile>, <string variableName>, [string[] constructorArguments]) -> void
_createObject() {
type=$1
associatedFile=$2
varName=$3
constructorArguments="${@:4}"
# Get a temporary variable. It's equivalent to the memory space in bash of the object.
varTmpName="_obj${_counter}"
_counter=$((_counter + 1))
# Declare dummy constructor.
eval "$varTmpName.constructor() { :; }"
# Declare base properties.
eval "$varTmpName.type() { echo $type; }"
eval "$varTmpName.source() { echo $associatedFile; }"
# Create property array.
createPropertyHolder $varTmpName
# alias the "varTmpName" variable to itself, so that it can be used and transmitted in other variables (e.g: $varName.name would alias to varTmpName.name)
eval "$varName='$varTmpName'"
# Imports the file and replace all "<Type>." with the variable name.
. <(sed s/this\\./$varTmpName./g <(sed s/$type\\./$varTmpName./g $associatedFile))
# Call the constructor
$varName.constructor $constructorArguments
}
# Declares a new class named `type` in the current namespace being defined in `associatedFile`.
# Signature: (<string type>, <string associatedFile>) -> void
class() {
type=$1 # Type of the object as declared within the file.
associatedFile=$2
objFullName=$type # Type of the object referenced elsewhere
if [ "$_namespace" != "" ]; then
objFullName="${_namespace}.$type"
fi
if [ ${associatedFile::1} != "/" ]; then # Relative path, we save only the absolute path
associatedFile="$_namespacePath/$associatedFile"
fi
# Declares a new function for object initialisation.
eval "$objFullName() { _createObject $type $associatedFile \$@; }"
# Save the class in the dictionnary for reference.
if [ "$_namespace" != "" ]; then
if [ "${_namespacesClasses[$_namespace]}" == "" ]; then
_namespacesClasses[$_namespace]=$type
else
_namespacesClasses[$_namespace]="${_namespacesClasses[$_namespace]};$type"
fi
fi
}
# Declares a new static class named `type` in the current namespace being defined in `associatedFile`.
# Signature: (<string type>, <string associatedFile>) -> void
static_class() {
type=$1 # Type of the object as declared within the file.
associatedFile=$2
objFullName=$type # Type of the object referenced elsewhere
if [ "$_namespace" != "" ]; then
objFullName="${_namespace}.$type"
fi
if [ ${associatedFile::1} != "/" ]; then # Relative path, we save only the absolute path
associatedFile="$_namespacePath/$associatedFile"
fi
# Imports the file and replace all "<Type>." with the variable name.
. <(sed s/this\\./$objFullName./g <(sed s/$type\\./$objFullName./g $associatedFile))
# Save the class in the dictionnary for reference.
if [ "$_namespace" != "" ]; then
if [ "${_namespacesStaticClasses[$_namespace]}" == "" ]; then
_namespacesStaticClasses[$_namespace]="$type:$associatedFile"
else
_namespacesStaticClasses[$_namespace]="${_namespacesStaticClasses[$_namespace]};$type:$associatedFile"
fi
fi
}
# Gets or sets the value of the property `propertyName` of an object set to variable `variableName`.
# Signature: (<string variableName>, <string propertyName>, [string operator, string value]) -> string|void
_accessProperty() {
varName=$1
prop=$2
val="${@:4}"
if [ "$3" == "=" ]; then
eval "_${varName}_properties[$prop]=\"\$val\""
else
eval "echo \"\${_${varName}_properties[$prop]}\""
fi
}
# Declares a property `propertyFullName` with an optional default value `propertyValue`.
# Signature: (<string propertyFullName>, [string propertyValue]) -> void
property() {
propertyFullName=$1
propertyValue=$2
# Split the name by ".". First element is variable name,
# second is property name.
propertyNames=($(echo $propertyFullName | tr "." "\n"))
varName=${propertyNames[0]}
prop=${propertyNames[1]}
# Default value
eval "_${varName}_properties[$prop]='$propertyValue'"
# Property alias
eval "$propertyFullName() { _accessProperty $varName $prop \$1 \"\${@:2}\"; }"
}