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module demo::lang::Lisra::Parse

rascal-0.40.17

Usage​

import demo::lang::Lisra::Parse;

Dependencies​

import Prelude;
import demo::lang::Lisra::Syntax;
import demo::lang::Lisra::Runtime;

function parse​

Lval parse(str txt) = build(parse(#LispExp, txt));

function build​

Build Abstract Syntax Tree: Transform a LispExp to an Lval.


Lval build((LispExp)`<IntegerLiteral il>`) = Integer(toInt("<il>"));

Lval build((LispExp)`<AtomExp at>`)        = Atom("<at>");

Lval build((LispExp)`( <LispExp* lst> )`)  = List([build(l) | l <- lst]);

Tests

test build1​

test bool build1() = build((LispExp) `42`) == Integer(42);

test build2​

test bool build2() = build((LispExp) `abc`) == Atom("abc");

test build3​

test bool build3() = build((LispExp) `(abc 42)`) == List([Atom("abc"), Integer(42)]);

test parse1​

test bool parse1() = parse("123") == Integer(123);

test parse2​

test bool parse2() = parse("abc") == Atom("abc");

test parse3​

test bool parse3() = parse("()") == List([]);

test parse4​

test bool parse4() = parse("(123)") == List([Integer(123)]);

test parse5​

test bool parse5() = parse("(123 abc)") == List([Integer(123), Atom("abc")]);