simon/post-scarcity
1
0
Fork 0
Code Issues 2 Pull requests Projects Releases Packages Wiki Activity Actions

Complete reworking of the REPL

Browse source 
which is good in itself, but not what I was meant to be working on.
This commit is contained in:
Simon Brooke 2018-12-30 17:56:15 +00:00
parent 47f4b4c7f7
commit 02fe5669d8
43 changed files with 415 additions and 281 deletions
Download patch file Download diff file Expand all files Collapse all files

108
src/repl.c
View file

@ -11,118 +11,28 @@
#include <stdio.h>
#include <wchar.h>
#include "conspage.h"
#include "consspaceobject.h"
#include "debug.h"
#include "intern.h"
#include "lispops.h"
#include "read.h"
#include "print.h"
#include "stack.h"
/* TODO: this is subtly wrong. If we were evaluating
* (print (eval (read)))
* then the stack frame for read would have the stack frame for
* eval as parent, and it in turn would have the stack frame for
* print as parent.
*/
/**
* Dummy up a Lisp read call with its own stack frame.
* The read/eval/print loop.
*/
struct cons_pointer repl_read( struct cons_pointer stream_pointer ) {
struct cons_pointer result = NIL;
debug_print( L"Entered repl_read\n", DEBUG_REPL );
struct cons_pointer frame_pointer =
make_stack_frame( NIL, make_cons( stream_pointer, NIL ), oblist );
debug_print( L"repl_read: got stack_frame pointer\n", DEBUG_REPL );
debug_dump_object( frame_pointer, DEBUG_REPL );
void repl( ) {
debug_print( L"Entered repl\n", DEBUG_REPL );
struct cons_pointer frame_pointer = make_stack_frame( NIL, NIL, oblist );
if ( !nilp( frame_pointer ) ) {
inc_ref( frame_pointer );
result =
lisp_read( get_stack_frame( frame_pointer ), frame_pointer,
oblist );
lisp_repl( get_stack_frame( frame_pointer ), frame_pointer, oblist );
dec_ref( frame_pointer );
}
debug_print( L"repl_read: returning\n", DEBUG_REPL );
debug_dump_object( result, DEBUG_REPL );
return result;
}
/**
* Dummy up a Lisp eval call with its own stack frame.
*/
struct cons_pointer repl_eval( struct cons_pointer input ) {
debug_print( L"Entered repl_eval\n", DEBUG_REPL );
struct cons_pointer result = NIL;
result = eval_form( NULL, NIL, input, oblist );
debug_print( L"repl_eval: returning\n", DEBUG_REPL );
debug_dump_object( result, DEBUG_REPL );
return result;
}
/**
* Dummy up a Lisp print call with its own stack frame.
*/
struct cons_pointer repl_print( struct cons_pointer stream_pointer,
struct cons_pointer value ) {
debug_print( L"Entered repl_print\n", DEBUG_REPL );
debug_dump_object( value, DEBUG_REPL );
struct cons_pointer result =
print( pointer2cell( stream_pointer ).payload.stream.stream, value );
debug_print( L"repl_print: returning\n", DEBUG_REPL );
debug_dump_object( result, DEBUG_REPL );
return result;
}
/**
* The read/eval/print loop
* @param in_stream the stream to read from;
* @param out_stream the stream to write to;
* @param err_stream the stream to send errors to;
* @param show_prompt true if prompts should be shown.
*/
void
repl( FILE * in_stream, FILE * out_stream, FILE * error_stream,
bool show_prompt ) {
debug_print( L"Entered repl\n", DEBUG_REPL );
struct cons_pointer input_stream = make_read_stream( in_stream );
inc_ref( input_stream );
struct cons_pointer output_stream = make_write_stream( out_stream );
inc_ref( output_stream );
while ( !feof( pointer2cell( input_stream ).payload.stream.stream ) ) {
if ( show_prompt ) {
fwprintf( out_stream, L"\n:: " );
}
struct cons_pointer input = repl_read( input_stream );
inc_ref( input );
if ( exceptionp( input ) ) {
/* suppress the end-of-stream exception */
if ( !feof( pointer2cell( input_stream ).payload.stream.stream ) ) {
repl_print( output_stream, input );
}
break;
} else {
struct cons_pointer val = repl_eval( input );
inc_ref( val );
repl_print( output_stream, val );
dec_ref( val );
}
dec_ref( input );
}
dec_ref( input_stream );
dec_ref( output_stream );
debug_print( L"Leaving repl\n", DEBUG_REPL );
}