This shall be called before calling any other function. This initialize Eclipse engine.
| Raise : | pyclpEx in case of failure or if eclipse engine is already initialized |
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This shutdown the Eclipse engine. After calling this function any operation on pyclp object or class could crash the program.
| Raise : | pyclpEx in case of failure or if eclipse engine is already shutdown |
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Warning
If after a cleanup it is called again pyclp.init() all terms created before the cleanup are not valid and they need to be rebuilt.
Cut all choice point of succeeded goal. Equivalent to void ec_cut_to_chp(ec_ref) It can be called only if previous resume call SUCCEED.
See also
For an example see Cut Example
Implements unify as described in ec_unify This function shall be used only inside python function tha are called from ECLiPSe
| Returns: | pyclp.SUCCEED or pyclp.FAIL |
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Register a python function to be called from Eclipse using the predicate call_python. It shall be called after init()
E.g. call_python(<eclipse_name>,<list of terms.>).
The registered python function will be called as:
<func>(<list of terms>)
The registered function shall return pyclp.SUCCEED or any other value for reporting FAIL.
| Parameters: |
|
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Resume Eclipse engine. Implements the functionality of ec_resume,ec_resume1,ec_resume2. It accepts optional argument in_term. Used to return a value to the prolog predicate yield/2
| Parameters: | in_term (PList, Atom, Compound) – Optional argument in_term. Used to return a value to the prolog predicate yield/2 |
|---|---|
| Return type: | tuple |
| Returns: | (pyclp.SUCCEED,None) if execution succeed (equivalent to True). In this case it is possible to call pyclp.cut() (pyclp.FAIL,None) if the goal fails. (pyclp.FLUSHIO,stream_number) if some data is present in stream identified by stream_number (pyclp.WAITIO,stream_number) if eclipse engine try to read data from stream identified by stream_number (pyclp.YIELD, yield_returned_value) in case of predicate call yield/2. (pyclp.THROW, Term TagExit) an event have been thrown and no one have catched it exit_block/1. |
Warning
After receiving FLUSHIO or WAITIO a new resume shall be issued before creating variable or calling post_goal to complete the goal execution and avoid unpredictable behavior.
Note
PyCLP have a different behavior compared to C/C++/Java default libraries provided by ECLiPsE. Standard resume execution destroys all the terms built before the execution of resume function while PyCLP is preserving them creating a reference and storing the created term in this.
See also
Class to create Atom.
| Parameters: | atom_id (string) – atom name |
|---|---|
| Inherited-members : | |
Convert to string for pretty printing
Class to create compound terms.
| Parameters: |
|---|
len(arg) function called with a Compound object return the arity of compound term.
This class support iterator protocol this means that you can iterate over term arguments or get the arguments by index protocol:
Example:
init()
my_compound=Compound("test",1,"dummy")
for x in my_compound:
print(x)
print(my_compound[0]) # Print first argument.
Warning
As for all other terms it is not possible to change their values.
| Inherited-members : | |
|---|---|
|
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| Returns: | string storing name of functor |
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| Returns: | arity of Compound object. |
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Class to create Prolog variable.
| Inherited-members : | |||
|---|---|---|---|
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Class to create and read Prolog lists.
When creating a new instance a list or tuple shall be provided. string,float and integer are automatically transformed in term as in Compound class. This class support iterator protocol this means that you can loop on the list as for python list
Example:
init()
my_list=PList([1,2,3])
for x in my_list:
print(x)
This class support retrieving values by indexing.
Example:
init()
my_list=PList([1,2,3])
print(my_list[3])
Warning
As for all other terms it is not possible to change their values.
Special cases
Empty prolog list can be created with PList([]) To check that a returned PList is the empty list it avaiable the method pyclp.PList.isNil()
Head Tail
In prolog it is possible to define a list using the operator |
Example of prolog list and head tail decomposition:
%Prolog list example
[1,2,3|myAtom]
[1|A]
%Also regular list have a tail: []
[1,2,3]=[1,2,3|[]]
%All list can be decomposed recursively as head tail couple
[1,2,3]
[1|[2,3]]
[1|[2|[3]]]
[1|[2|[3|[]]]]
Pretty printing of the list
Convert a PList in a python list and the tail.
Examples:
prolog python
[1,2,3,f(1,2)] --> ([1,2,3,Compound('f',1,2)],PList([]))
[1,2,3|A] --> ([1,2,3],Var())
[1,2,3|dummy] --> ([1,2,3],Atom('dummy'))
| Returns: | a tuple (list,tail). First element is a python list containing each element of prolog list converted to a pyclp object second element is a pyclp object representing the tail of prolog list. |
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Check if the PList is the nil list –> []
| Returns: | True if it is the empty list |
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| Returns: | Iterator that returns a tuple (head,tail) where head is a element of the list and tail is the remaining list |
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Deprecated since version 1.5.
Replaced by PList.iterHeadTail()
Post goal
Class to support streams to and from ECLiPSe. This is class is derived from io.RawIOBase.
| Parameters: | name – string containing stream name of a previously opened stream by ECLiPSe program. See: Embedded C stream api and get_stream/2 |
|---|
Note
The following stream are already opened: ‘input’, ‘output’, ‘error’, ‘warning_output’, ‘log_output’, ‘stdin’, ‘stdout’, ‘stderr’, ‘null’.
| Raises IOError: | if name is not matching a previously open stream by open/3 and open/4 |
|---|
Read all bytes from stream
| Parameters: | n – Number of bytes to be read if omitted or equal to -1 it will return all avaiable bytes. |
|---|---|
| Returns: | bytes object |
Write a bytes object to stream. :type buffer: bytes object. :return: number of bytes written
Read all available bytes equivalent to pyclp.read()