yep

parsers/instruction.js

@@ -25,7 +25,7 @@ function instructionName () {
 function instruction () {
   return mona.sequence((s) => {
     const i = s(instructionName())
-    const space = s(mona.spaces())
+    const space = s(mona.maybe(mona.spaces()))
     const args = s(mona.maybe(parameters()))
     // const nl = s(mona.eol())
     return mona.value({

parsers/parameters.js

@@ -1,16 +1,11 @@
 const mona = require('mona')
 
 function quotedChar () {
-  return mona.or(mona.noneOf('"'),
-                 mona.and(mona.string('""'),
-                          mona.value('"')))
-}
-
-function alphanum () {
-  return mona.join(
-    mona.value('alphanum'),
-    mona.string('background3')
-  )
+  return mona.or(
+    mona.noneOf('"'),
+    mona.and(
+      mona.string('""'),
+      mona.value('"')))
 }
 
 function bit () {
@@ -68,28 +63,39 @@ function address () {
   )
 }
 
-function parameter () {
-  return mona.collect(
-    mona.or(
-      address(),
-      binary(),
-      hex(),
-      string(),
-      bit(),
-      alphanum()
+// this is the fallthrough parser
+function alphanum () {
+  return mona.join(
+    mona.value('alphanum'),
+    mona.and(
+      mona.not(bit()),
+      mona.not(address()),
+      mona.not(binary()),
+      mona.not(bit()),
+      mona.not(string()),
+      mona.text(mona.alphanum())
     )
   )
 }
 
+function parameter () {
+  return mona.or(
+    address(),
+    binary(),
+    hex(),
+    string(),
+    bit(),
+    alphanum()
+  )
+}
+
 function parameters () {
-  return mona.map(a => a.map(b => b[0]),
-    mona.split(
-      parameter(),
-      mona.or(
-        mona.and(mona.string(','), mona.spaces()),
-        mona.string(','),
-        mona.spaces()
-      )
+  return mona.split(
+    parameter(),
+    mona.or(
+      mona.and(mona.string(','), mona.spaces()),
+      mona.string(','),
+      mona.spaces()
     )
   )
 }

test/assembler.js

@@ -8,7 +8,10 @@ tap.test('should parse the basics', (t) => {
     {
       directive: '.org',
       args: [
-        '$,C000'
+        [
+          'address',
+          'C000'
+        ]
       ]
     },
     {

test/instruction.js

@@ -4,7 +4,7 @@ const instructionParser = require('../parsers/instruction')
 
 tap.test('will parse an instruction', (t) => {
   t.plan(1)
-  t.deepEqual(mona.parse(instructionParser(), 'sei'), {
+  t.deepEqual(mona.parse(instructionParser(), 'sei\n'), {
     args: null,
     instruction: 'sei'
   })
@@ -12,7 +12,7 @@ tap.test('will parse an instruction', (t) => {
 
 tap.test('will parse an instruction with args', (t) => {
   t.plan(1)
-  t.deepEqual(mona.parse(instructionParser(), 'stx $2000'), {
+  t.deepEqual(mona.parse(instructionParser(), 'stx $2000\n'), {
     args: [
       [
         'address',
@@ -25,7 +25,7 @@ tap.test('will parse an instruction with args', (t) => {
 
 tap.test('will parse an instruction with multiple args', (t) => {
   t.plan(1)
-  t.deepEqual(mona.parse(instructionParser(), 'lda background3, x'), {
+  t.deepEqual(mona.parse(instructionParser(), 'lda background3, x\n'), {
     args: ['background3', 'x'],
     instruction: 'lda'
   })

test/parameters.js

@@ -11,6 +11,21 @@ tap.test('should parse direct memory address param', (t) => {
   ])
 })
 
+tap.test('should parse alphanum param', (t) => {
+  t.plan(1)
+  const input = 'background3'
+  t.deepEqual(mona.parse(parsers.alphanum(), input), [
+    'alphanum',
+    'background3'
+  ])
+})
+
+tap.test('should not parse alphanum param if empty', (t) => {
+  t.plan(1)
+  const input = ''
+  t.notOk(mona.parse(parsers.alphanum(), input))
+})
+
 tap.test('should parse hex param', (t) => {
   t.plan(1)
   const input = '#$FF'
@@ -31,13 +46,10 @@ tap.test('should parse binary param', (t) => {
 
 tap.test('should parse param', (t) => {
   t.plan(1)
-
   const input = '#%00000001'
   t.deepEqual(mona.parse(parsers.parameter(), input), [
-    [
-      'binary',
-      '00000001'
-    ]
+    'binary',
+    '00000001'
   ])
 })