ulambda/build-aux/bootstrap/libprebirth.js

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/**
* Transition library for Prebirth
*
* Copyright (C) 2017 Mike Gerwitz
*
* This file is part of Gibble.
*
* Gibble is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* THIS IS TEMPORARY CODE that will be REWRITTEN IN GIBBLE LISP ITSELF after
* a very basic bootstrap is complete. It is retained as an important
* artifact for those who wish to build Gibble from scratch without using
* another version of Gibble itself. This is called "self-hosting".
*
* For the actual Prebirth compiler before self-hosting, see `prebirth.js'
* in the same directory as this file.
*
* This library is intended to be concatenated with the compiled
* Prebirth Lisp to ease the transition by providing a set of functions that
* will Just Work™ without a Prebirth Lisp implementation. They will be
* removed as they are rewritten in Prebirth Lisp.
*
* By convention, everything is prefixed with `js:' in Prebirth (not `es:',
* because we're using JavaScript-specific features). For character
* transformation rules, see `Compiler#_idFromName' in `prebirth.js'.
*
* These implementations are largely flawed in some manner, but that's okay,
* because they do their job. Some flaws are noted.
*/
const $$$h$t = true;
const $$$h$f = false;
const $$symbol$q$$7$ = ( a, b ) => ( ( typeof a === 'symbol' ) && ( a === b ) );
const argToArr = args => Array.prototype.slice.call( args );
function $$list() { return argToArr( arguments ); }
const _error = str =>
{
throw Error( str );
}
const _assertPair = xs =>
{
_assertList( xs );
if ( xs.length === 0 ) {
throw TypeError( "expecting pair" );
}
return true;
}
const _assertList = xs =>
{
if ( !Array.isArray( xs ) ) {
throw TypeError( "expecting list" );
}
return true;
}
// only false (#f in Scheme) is non-true
const _truep = x => x !== false;
// ignore obj for now
const $$error = ( msg, obj ) => _error( msg );
const $$cons = ( item, list ) => _assertList( list ) && [ item ].concat( list )
const $$car = xs => _assertPair( xs ) && xs[ 0 ];
const $$cdr = xs => _assertPair( xs ) && xs.slice( 1 );
// warning: blows up if any items are non-lists, whereas the proper RnRS
// implementation will set the cdr to the final item even if it's not a pair
function $$append()
{
return argToArr( arguments )
.reduce( ( xs, x ) => xs.concat( _assertList( x ) && x ) );
}
const $$list$7$ = xs => Array.isArray( xs );
const $$pair$7$ = xs => Array.isArray( xs ) && ( xs.length > 0 );
// R7RS string
const $$substring = ( s, start, end ) => s.substring( start, end );
const $$string$_$length = s => s.length;
const $$string$q$$7$ = ( x, y ) => x === y;
const $$string$_$ref = ( s, i ) => s[ i ]
|| _error( `value out of range: ${i}`);
function $$string$_$append()
{
return argToArr( arguments ).join( "" );
}
// R7RS math
function $$$p$()
{
return argToArr( arguments ).reduce( ( ( x, y ) => x + y ), 0 );
}
function $$$_$()
{
const args = argToArr( arguments );
const first = args.shift();
return args.reduce( ( ( x, y ) => x - y ), first );
}
const $$zero$7$ = x => x === 0;
// SRFI-1
// warning: fold here only supports one list
const $$fold = ( f, init, xs ) =>
xs.reduce( ( prev, x ) => f( x, prev ), init );
// warning: map here uses the length of the first list, not the shortest
// (we implement this in ES for now so that we don't have to augment
// Prebirth Lisp to support the "rest" procedure definition syntax)
const $$map = ( f, ...xs ) =>
xs[ 0 ].map(
( _, i ) => f.apply( null,
xs.map( x => x[ i ] ) ) );
const $$js$regexp = ( s, opts ) => new RegExp( s, opts );
const $$js$match = ( r, s ) => s.match( r ) || false;
const $$js$replace = ( r, repl, s ) => s.replace( r, repl );
// the variable __fsinit, if defined, can be used to stub the filesystem
const fsdata = ( typeof __fsinit !== 'undefined' ) ? __fsinit : {};
const fs = ( typeof require !== 'undefined' )
? require( 'fs' )
: {
readFileSync( path )
{
throw Error( `Cannot load ${path} (no fs module)` );
},
}
// file->string
const $$js$file$_$$g$string = ( path ) =>
{
if ( fsdata[ path ] !== undefined ) {
return fsdata[ path ];
}
return fsdata[ path ] = fs.readFileSync( path ).toString();
};
/** =============== end of libprebirth =============== **/