com.github.jlangch.venice.impl

Class VeniceInterpreter

java.lang.Object

com.github.jlangch.venice.impl.VeniceInterpreter

public class VeniceInterpreter
extends java.lang.Object

Constructor Summary

Constructors

Constructor and Description
VeniceInterpreter()

Method Summary

Modifier and Type	Method and Description
Env	createEnv(java.io.PrintStream stdout)
VncVal	eval_ast(VncVal ast, Env env)
VncVal	EVAL(VncVal orig_ast, Env env)
boolean	is_macro_call(VncVal ast, Env env) Returns true if ast is a list that contains a symbol as the first element and that symbol refers to a function in the env environment and that function has the is_macro attribute set to true.
static boolean	is_pair(VncVal x)
VncVal	macroexpand(VncVal ast, Env env) Recursively expands a macro.
java.lang.String	PRINT(VncVal exp)
static VncVal	quasiquote(VncVal ast)
VncVal	RE(java.lang.String script, java.lang.String filename, Env env)
VncVal	READ(java.lang.String script, java.lang.String filename)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

VeniceInterpreter

public VeniceInterpreter()

Method Detail

READ

public VncVal READ(java.lang.String script,
                   java.lang.String filename)

is_pair

public static boolean is_pair(VncVal x)

quasiquote

public static VncVal quasiquote(VncVal ast)

is_macro_call

public boolean is_macro_call(VncVal ast,
                             Env env)

Returns true if ast is a list that contains a symbol as the first element and that symbol refers to a function in the env environment and that function has the is_macro attribute set to true. Otherwise, it returns false.

Parameters:

ast - ast

env - env

Returns:

true if the ast starts with a macro

macroexpand

public VncVal macroexpand(VncVal ast,
                          Env env)

Recursively expands a macro. It calls is_macro_call with ast and env and loops while that condition is true. Inside the loop, the first element of the ast list (a symbol), is looked up in the environment to get the macro function. This macro function is then called/applied with the rest of the ast elements (2nd through the last) as arguments. The return value of the macro call becomes the new value of ast. When the loop completes because ast no longer represents a macro call, the current value of ast is returned.

Parameters:

ast - ast

env - env

Returns:

the expanded macro

eval_ast

public VncVal eval_ast(VncVal ast,
                       Env env)

EVAL

public VncVal EVAL(VncVal orig_ast,
                   Env env)

PRINT

public java.lang.String PRINT(VncVal exp)

RE

public VncVal RE(java.lang.String script,
                 java.lang.String filename,
                 Env env)

createEnv

public Env createEnv(java.io.PrintStream stdout)