ast_generator/parser.ne

@preprocessor typescript

@{%
import * as moo from "https://deno.land/x/moo@0.5.1-deno.2/mod.ts";
import * as ast from "./ast.out.ts";

const lexer: any = moo.compile({

    newline: { match: /[\n]+/, lineBreaks: true },
    whitespace: /[ \t]+/,

    singleLineComment: /\/\/.*?$/,
    multiLineComment: { match: /\*[^*]*\*+(?:[^/*][^*]*\*+)*/, lineBreaks: true },

    name: {
        match: /[a-zA-Z0-9_]+/,
        type: moo.keywords({
            keyword: [],
        }),
    },

    lparen: "(",
    rparen: ")",
    lbrace: "{",
    rbrace: "}",
    lbracket: "[",
    rbracket: "]",
    colon: ":",
    comma: ",",
    questionmark: "?",
});
%}

@lexer lexer

file -> elements {% id %}

elements -> _ (element elementTail _):? {% v => v[1] ? [v[1][0], ...v[1][1]] : [] %}

elementTail -> (nl__ element):* {% v => v[0].map(w => w[1]) %}

element ->  enum {% v => ast.EnumStatement(v[0]) %}
        |   node {% v => ast.NodeStatement(v[0]) %}

enum -> name _ "{" nodes "}" {% v => ast.Enum(v[0], v[3]) %}

nodes -> _ (node nodeTail _):? {% v => v[1] ? [v[1][0], ...v[1][1]] : [] %}

nodeTail -> (nl__ node):* {% v => v[0].map(w => w[1]) %}

node -> name _ "(" params ")" {% v => ast.Node(v[0], v[3]) %}

params -> _ (param paramTail (_ ","):? _):? {% v => v[1] ? [v[1][0], ...v[1][1]] : [] %}

paramTail -> ("," _ param):* {% v => v[0].map(w => w[2]) %}

param   ->  namedParam {% id %}
        |   unnamedParam {% id %}

namedParam -> name _ ":" _ type {% v => ast.NamedParam(v[0], v[4]) %}

unnamedParam -> type {% v => ast.UnnamedParam(v[0]) %}

type -> optional {% id %}
    |   multiple {% id %}
    |   name {% v => ast.NameType(v[0]) %}

optional -> type "?" {% v => ast.OptionalType(v[0]) %}

multiple -> type "[" "]" {% v => ast.MultipleType(v[0]) %}

name -> %name {% v => ast.Name(v[0].value, v[0].line, v[0].col) %}

_           ->  __:?
__          ->  (%whitespace|%newline|%singeLineComment|%multiLineComment):+

nl__        ->  sl_ (%newline sl_):+

sl_         ->  sl__:?
sl__        ->  (%whitespace|%singleLineComment|%multiLineComment):+