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Merge pull request #360 from notoria/master

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Add get_single_char predicate.
This commit is contained in:
Mark Thom
2020-04-18 14:10:26 -03:00
committed by GitHub
parent 57d739673a 6996ca832d
commit 500bd53b6a
5 changed files with 49 additions and 63 deletions
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4
README.md
View File

@@ -168,8 +168,8 @@ predicates it defines. For example, with the program shown above:
; What = pure_world.
```
Press `SPACE` to show further answers, if any exist. Press `.` to
abort the search and return to the toplevel prompt.
Press `SPACE` to show further answers, if any exist. Press `RETURN` or
 `.` to abort the search and return to the toplevel prompt.
Press `h` to show a help message.
To quit Scryer Prolog, use the standard predicate `halt/0`:

6
src/prolog/clause_types.rs
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@@ -178,6 +178,7 @@ pub enum SystemClauseType {
FetchGlobalVar,
FetchGlobalVarWithOffset,
GetChar,
GetSingleChar,
ResetAttrVarState,
TruncateIfNoLiftedHeapGrowthDiff,
TruncateIfNoLiftedHeapGrowth,
@@ -241,7 +242,6 @@ pub enum SystemClauseType {
InstallNewBlock,
Maybe,
QuotedToken,
RawInputReadChar,
ReadTermFromChars,
ResetBlock,
ReturnFromVerifyAttr,
@@ -309,6 +309,7 @@ impl SystemClauseType {
clause_name!("$fetch_global_var_with_offset")
}
&SystemClauseType::GetChar => clause_name!("$get_char"),
&SystemClauseType::GetSingleChar => clause_name!("$get_single_char"),
&SystemClauseType::ResetAttrVarState => clause_name!("$reset_attr_var_state"),
&SystemClauseType::TruncateIfNoLiftedHeapGrowth => {
clause_name!("$truncate_if_no_lh_growth")
@@ -364,7 +365,6 @@ impl SystemClauseType {
&SystemClauseType::QuotedToken => {
clause_name!("$quoted_token")
}
&SystemClauseType::RawInputReadChar => clause_name!("$raw_input_read_char"),
&SystemClauseType::RedoAttrVarBinding => clause_name!("$redo_attr_var_binding"),
&SystemClauseType::RemoveCallPolicyCheck => clause_name!("$remove_call_policy_check"),
&SystemClauseType::RemoveInferenceCounter => clause_name!("$remove_inference_counter"),
@@ -455,6 +455,7 @@ impl SystemClauseType {
("$fetch_global_var", 2) => Some(SystemClauseType::FetchGlobalVar),
("$fetch_global_var_with_offset", 3) => Some(SystemClauseType::FetchGlobalVarWithOffset),
("$get_char", 1) => Some(SystemClauseType::GetChar),
("$get_single_char", 1) => Some(SystemClauseType::GetSingleChar),
("$points_to_cont_reset_marker", 1) => {
Some(SystemClauseType::PointsToContinuationResetMarker)
}
@@ -506,7 +507,6 @@ impl SystemClauseType {
("$get_cp", 1) => Some(SystemClauseType::GetCutPoint),
("$install_new_block", 1) => Some(SystemClauseType::InstallNewBlock),
("$quoted_token", 1) => Some(SystemClauseType::QuotedToken),
("$raw_input_read_char", 1) => Some(SystemClauseType::RawInputReadChar),
("$nextEP", 3) => Some(SystemClauseType::NextEP),
("$read_query_term", 2) => Some(SystemClauseType::ReadQueryTerm),
("$read_term", 2) => Some(SystemClauseType::ReadTerm),

10
src/prolog/lib/charsio.pl
View File

@@ -1,4 +1,5 @@
:- module(charsio, [read_term_from_chars/2,
:- module(charsio, [get_single_char/1,
read_term_from_chars/2,
write_term_to_chars/3]).
:- use_module(library(iso_ext)).
@@ -56,6 +57,13 @@ extend_var_list_([V|Vs], N, VarList, NewVarList, VarType) :-
).
get_single_char(C) :-
( var(C) -> '$get_single_char'(C)
; atom_length(C, 1) -> '$get_single_char'(C)
; throw(error(domain_error(in_character, C), get_single_char/1))
).
read_term_from_chars(Chars, Term) :-
( var(Chars) ->
throw(error(instantiation_error, read_term_from_chars/2))

77
src/prolog/machine/system_calls.rs
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@@ -31,40 +31,30 @@ use std::rc::Rc;
use crate::crossterm::event::{read, Event, KeyCode, KeyEvent};
use crate::crossterm::terminal::{enable_raw_mode, disable_raw_mode};
pub enum ContinueResult {
ContinueQuery,
Conclude,
Help,
PrintWithoutMaxDepth,
PrintWithMaxDepth
}
pub fn next_keypress() -> ContinueResult {
pub fn get_single_char() -> char {
let c;
enable_raw_mode().expect("failed to enable raw mode");
loop {
match read() {
Ok(Event::Key(KeyEvent { code, .. })) => {
match code {
KeyCode::Char('w') => {
return ContinueResult::PrintWithoutMaxDepth;
}
KeyCode::Char('p') => {
return ContinueResult::PrintWithMaxDepth;
}
KeyCode::Char(' ') | KeyCode::Char(';') | KeyCode::Char('n') => {
return ContinueResult::ContinueQuery;
}
KeyCode::Char('.') => {
return ContinueResult::Conclude;
}
KeyCode::Char('h') => {
return ContinueResult::Help;
}
_ => {}
}
if let Ok(Event::Key(KeyEvent { code, .. })) = read() {
match code {
KeyCode::Char(ch) => {
c = ch;
break;
},
KeyCode::Enter => {
c = '\n';
break;
},
KeyCode::Tab => {
c = '\t';
break;
},
_ => ()
}
_ => {}
}
}
disable_raw_mode().expect("failed to disable raw mode");
c
}
struct BrentAlgState {
@@ -1463,6 +1453,13 @@ impl MachineState {
}
}
}
&SystemClauseType::GetSingleChar => {
let c = get_single_char();
let a1 = self[temp_v!(1)];
self.unify(Addr::Char(c), a1);
}
&SystemClauseType::GetModuleClause => {
let module = self[temp_v!(3)];
let head = self[temp_v!(1)];
@@ -2880,26 +2877,6 @@ impl MachineState {
&SystemClauseType::InstallNewBlock => {
self.install_new_block(temp_v!(1));
}
&SystemClauseType::RawInputReadChar => {
let keypress = {
enable_raw_mode().expect("failed to transition into raw mode");
let result = next_keypress();
disable_raw_mode().expect("failed to transition out of raw mode");
result
};
let c = match keypress {
ContinueResult::ContinueQuery => ';',
ContinueResult::Conclude => '.',
ContinueResult::Help => 'h',
ContinueResult::PrintWithoutMaxDepth => 'w',
ContinueResult::PrintWithMaxDepth => 'p',
};
let target = self[temp_v!(1)];
self.unify(Addr::Char(c), target);
}
&SystemClauseType::NextEP => {
let first_arg = self.store(self.deref(self[temp_v!(1)]));

15
src/prolog/toplevel.pl
View File

@@ -145,30 +145,31 @@
).
'$read_input'(ThreadedGoals, NewVarList) :-
'$raw_input_read_char'(C),
( C == w ->
get_single_char(C),
( C = w ->
nl,
write(' '),
'$write_eq'(ThreadedGoals, NewVarList, 0),
'$read_input'(ThreadedGoals, NewVarList)
; C == p ->
; C = p ->
nl,
write(' '),
'$write_eq'(ThreadedGoals, NewVarList, 20),
'$read_input'(ThreadedGoals, NewVarList)
; C == (';') ->
; member(C, [';', ' ', n]) ->
nl, write('; '), false
; C == h ->
; C = h ->
'$help_message',
'$read_input'(ThreadedGoals, NewVarList)
; C == '.',
; member(C, ['\n', .]) ->
nl, write('; ...'), nl
; '$read_input'(ThreadedGoals, NewVarList)
).
'$help_message' :-
nl, nl,
write('SPACE, "n" or ";": next solution, if any\n'),
write('".": stop enumeration\n'),
write('RETURN or ".": stop enumeration\n'),
write('"h": display this help message\n'),
write('"w": write terms without depth limit\n'),
write('"p": print terms with depth limit\n\n').