add sequence parsers

src/combinator.js

@@ -2,6 +2,7 @@ import { chain, curry } from 'izuna'
 import { ok } from 'kojima'
 import { clone, diff, fail, succeed } from './fn.js'
 import { state as State } from './state.js'
+import { skip } from './cond.js'
 
 /** @import { ParserState } from './state.js' */
 
@@ -62,3 +63,9 @@ export const map = curry(
     })
   })
 
+export const delimited = curry((first, second, third, state) => seq(skip(first), second, skip(third))(state))
+export const preceded = curry((first, second, state) => seq(skip(first), second)(state))
+export const terminated = curry((first, second, state) => seq(first, skip(second))(state))
+
+export const separatedPair = curry((first, delimiter, second, state) => seq(first, skip(delimiter), second)(state))
+

src/cond.js

@@ -50,5 +50,6 @@ export const verify = curry((parser, predicate, state) => {
 })
 
 export const skip = curry((parser, state) => {
+  return chain(_ => succeed([], state), parser(state))
 })
 

tests/units/bytes.js

@@ -2,18 +2,7 @@ import { it, assert, assertEq } from 'folktest'
 import { char, charNoCase, noneOf, oneOf, parse, tag, tagNoCase, take, takeWhile } from '../../src/index.js'
 import { Alphanumeric } from '../../src/const.js'
 import { chain, curry, map } from 'izuna'
-
-const assertState = expected => state => {
-  assertEq(expected, state[0])
-}
-
-const parseEq = curry((parser, input, expected) =>
-  chain(assertState(expected), parse(parser, input))
-)
-
-const parseErr = curry((parser, input) =>
-  assert(parse(parser, input).isErr(), `expected an error but "${input}" parsed successfully`)
-)
+import { assertState, parseEq } from './common.js'
 
 export const Byte = [
   it('char', () => {

tests/units/common.js

@@ -0,0 +1,15 @@
+import { chain, curry } from 'izuna'
+import { parse } from '../../src/index.js'
+
+export const assertState = curry((expected, state) => {
+  assertEq(expected, state[0])
+})
+
+export const parseEq = curry((parser, input, expected) =>
+  chain(assertState(expected), parse(parser, input))
+)
+
+export const parseErr = curry((parser, input) =>
+  assert(parse(parser, input).isErr(), `expected an error but '${input}' parsed successfully`)
+)
+

tests/units/cond.js

@@ -0,0 +1,11 @@
+import { it, assertEq } from 'folktest'
+import { anyChar, parse } from '../../src/index.js'
+import { skip } from '../../src/cond.js'
+import { parseEq } from './common.js'
+
+export const Conditionals = [
+  it('skip', () => {
+    parseEq(skip(anyChar), 'test', [])
+  })
+]
+

tests/units/index.js

@@ -1,3 +1,4 @@
 export * from './bytes.js'
 export * from './iter.js'
+export * from './cond.js'