Improve documentation

* Add some notes about build pre-requisites, mostly Mac because that's what I
use and next time I want to set up faster.
* Better explanation of what to do if the wrapper libs aren't being built.
* unify java_sml_alias and java_target
* Add "list" to the list of extra targets available from the build CLI

Core/ClientSMLSWIG/Java/SConscript

@@ -92,7 +92,7 @@ srcdir = clone.Dir('src')
 smldir = srcdir.Dir('sml')
 classdir = clone.Dir('classes')
 jar = clone.File('sml.jar')
-java_target = 'sml_java'
+java_target = java_sml_alias
 fake_java_target = '#fake_java_target'
 
 if sys.platform == 'darwin':

Core/SConscript

@@ -108,7 +108,7 @@ for d in ['ElementXML/src', 'ConnectionSML/src', 'ClientSML/src', 'shared']:
 env.Alias('headers', headers)
 
 if not CheckSWIG(env):
-	print('SWIG not found, will not attempt to build wrappers for other programming languages.')
+	print('SWIG not found. Will not define sml_* build targets. Install swig to build wrappers for other languages.')
 else:
 	for x in 'Python Java Tcl CSharp'.split():
 		SConscript(os.path.join('ClientSMLSWIG', x, 'SConscript'))

README.md

@@ -23,6 +23,31 @@ Some performance statistics are calculated automatically using the Factorization
 
 Disclaimer: These are worst case tests.  Average performance is probably much higher.  In addition, these show that even in worst case, Soar beats its goal of 50 msec reactivity (in these tests, the max is ~30msec per decision).
 
+# Development
+
+## Prerequisites
+
+To compile Soar, you will need the following:
+
+* C/C++ compiler
+    - Mac: `xcode-select --install`
+    - Linux: `sudo apt-get install build-essential`
+* Python
+    - Mac: `brew install python`
+* Java
+    - We recommend using [SDKMan](https://sdkman.io/). Install JDK 17 (Temurin is recommended).
+
+To compile the extra SML wrapper libs, you will need the following:
+
+* C# compiler (`csc`)
+    - Mac: `brew install mono`
+* Tcl
+    - Mac: `brew install tcl-tk`
+
+The project supports generating compile_commands.json, which can be used by e.g. VSCode with the C/C++ plugin to provide IntelliSense. To generate this file, run scons with the `cdb` target:
+
+   python3 scons/scons.py --scu --opt --verbose cdb
+
 # License
 
 Soar is available under the following [LICENSE](https://github.com/SoarGroup/Soar/blob/development/LICENSE.md).  This license is [BSD](http://opensource.org/licenses/BSD-2-Clause)

SConstruct

@@ -43,7 +43,7 @@ print("Targets available:")
 print("   Core:              kernel* cli* scripts*")
 print("   Testing:           performance_tests tests")
 print(f"   SWIG:              {SML_PYTHON_ALIAS} {SML_TCL_ALIAS} {SML_JAVA_ALIAS}* {SML_CSHARP_ALIAS}")
-print(f"   Extras:            debugger* headers* {COMPILE_DB_ALIAS}* tclsoarlib {MSVS_ALIAS}")
+print(f"   Extras:            debugger* headers* {COMPILE_DB_ALIAS}* tclsoarlib {MSVS_ALIAS} list")
 print("Custom Settings available:                                              *default")
 print("   Build Type:        --dbg, --opt*, --static")
 print("   Custom Paths:      --out, --build, --tcl")