mirror of
https://github.com/kanaka/mal.git
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a05c086f05
- Use Vector class derived from Array - Use Array/Vector.from for initializing/cloning of Array/Vector - Remove most semi-colon line endings - More use of arrow functions - Use Object.assign to copy properties in _malfunc and function cloning. - Remove or inline a bunch of types.js functions that don't really need to be separate functions: _obj_type, _sequential_Q, _symbol, _symbol_Q, _vector, _vector_Q, _hash_map, _hash_map_Q - Simplify dependency list in Makefile - Remove some separate core.js functions by moving them into the core_ns declaration: _nth, keys, vals, with_meta. With node 7, babel is mostly just used for translating imports into CommonJS requires for node.
82 lines
2.4 KiB
JavaScript
82 lines
2.4 KiB
JavaScript
import { readline } from './node_readline'
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import { _list_Q } from './types'
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import { BlankException, read_str } from './reader'
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import { pr_str } from './printer'
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import { new_env, env_set, env_get } from './env'
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import { core_ns } from './core'
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// read
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const READ = str => read_str(str)
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// eval
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const eval_ast = (ast, env) => {
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if (typeof ast === 'symbol') {
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return env_get(env, ast)
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} else if (ast instanceof Array) {
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return ast.map(x => EVAL(x, env))
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} else if (ast instanceof Map) {
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let new_hm = new Map()
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ast.forEach((v, k) => new_hm.set(EVAL(k, env), EVAL(v, env)))
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return new_hm
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} else {
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return ast
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}
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}
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const EVAL = (ast, env) => {
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//console.log('EVAL:', pr_str(ast, true))
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if (!_list_Q(ast)) { return eval_ast(ast, env) }
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if (ast.length === 0) { return ast }
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const [a0, a1, a2, a3] = ast
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switch (typeof a0 === 'symbol' ? Symbol.keyFor(a0) : Symbol(':default')) {
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case 'def!':
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return env_set(env, a1, EVAL(a2, env))
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case 'let*':
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let let_env = new_env(env)
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for (let i=0; i < a1.length; i+=2) {
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env_set(let_env, a1[i], EVAL(a1[i+1], let_env))
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}
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return EVAL(a2, let_env)
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case 'do':
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return eval_ast(ast.slice(1), env)[ast.length-2]
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case 'if':
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let cond = EVAL(a1, env)
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if (cond === null || cond === false) {
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return typeof a3 !== 'undefined' ? EVAL(a3, env) : null
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} else {
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return EVAL(a2, env)
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}
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case 'fn*':
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return (...args) => EVAL(a2, new_env(env, a1, args))
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default:
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let [f, ...args] = eval_ast(ast, env)
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return f(...args)
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}
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}
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// print
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const PRINT = exp => pr_str(exp, true)
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// repl
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let repl_env = new_env()
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const REP = str => PRINT(EVAL(READ(str), repl_env))
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// core.EXT: defined using ES6
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for (let [k, v] of core_ns) { env_set(repl_env, Symbol.for(k), v) }
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// core.mal: defined using language itself
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REP('(def! not (fn* (a) (if a false true)))')
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while (true) {
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let line = readline('user> ')
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if (line == null) break
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try {
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if (line) { console.log(REP(line)) }
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} catch (exc) {
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if (exc instanceof BlankException) { continue }
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if (exc.stack) { console.log(exc.stack) }
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else { console.log(`Error: ${exc}`) }
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}
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}
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