Class silk.Environment
java.lang.Object
|
+----silk.SchemeUtils
|
+----silk.Environment
- public class Environment
- extends SchemeUtils
Environments allow you to look up the value of a variable, given
its name. Keep a list of variables and values, and a pointer to
the parent environment. If a variable list ends in a symbol rather
than null, it means that symbol is bound to the remainder of the
values list.
Field Summary
Fields inherited from class silk.SchemeUtils
Constructor Summary
Environment (java.lang.Object vars,
java.lang.Object vals,
Environment parent)
A constructor to extend an environment with var/val pairs.
Environment ()
Construct an empty environment: no bindings.
Method Summary
java.lang.Object
define (java.lang.Object var,
java.lang.Object val)
Add a new variable,value pair to this environment.
java.lang.Object
lookup (java.lang.String symbol)
Find the value of a symbol, in this environment or a parent.
java.lang.Object
set (java.lang.Object var,
java.lang.Object val)
Set the value of an existing variable
chr,
chr,
cons,
equal,
eqv,
error,
first,
inPort,
length,
list,
list,
listStar,
listToString,
listToVector,
num,
num,
outPort,
rest,
reverse,
second,
setFirst,
setRest,
str,
sym,
third,
truth,
truth,
vec,
vectorToList,
warn,
write
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Field Detail
vars
public java.lang.Object vars
vals
public java.lang.Object vals
parent
public Environment parent
Constructor Detail
Environment
public Environment(java.lang.Object vars,
java.lang.Object vals,
Environment parent)
- A constructor to extend an environment with var/val pairs.
Environment
public Environment()
- Construct an empty environment: no bindings.
Method Detail
lookup
public java.lang.Object lookup(java.lang.String symbol)
- Find the value of a symbol, in this environment or a parent.
define
public java.lang.Object define(java.lang.Object var,
java.lang.Object val)
- Add a new variable,value pair to this environment.
set
public java.lang.Object set(java.lang.Object var,
java.lang.Object val)
- Set the value of an existing variable
defPrim
public Environment defPrim(java.lang.String name,
int id,
int minArgs)
defPrim
public Environment defPrim(java.lang.String name,
int id,
int minArgs,
int maxArgs)