Add support for simple import *statement* to identifier

I couldn't get import as an expression to work, so I resorted to define it as a
statement for now.

I'm pretty sure multi-line imports don't work either and there's no alias
functionality yet. So this is still *heavily* WIP.

Author: Alexander Pánek

src/grammar.coffee

@@ -97,6 +97,8 @@ grammar =
     o 'Return'
     o 'Comment'
     o 'STATEMENT',                              -> new StatementLiteral $1
+    o 'Import'
+    o 'Export'
   ]
 
   # All the different types of expressions in our language. The basic unit of
@@ -117,8 +119,6 @@ grammar =
     o 'Class'
     o 'Throw'
     o 'Yield'
-    o 'Import'
-    o 'Export'
   ]
 
   Yield: [
@@ -353,6 +353,7 @@ grammar =
 
   Import: [
     o 'IMPORT Expression',                      -> new Import $2
+    o 'IMPORT Assignable FROM Expression',      -> new Import $4, $2
   ]
 
   # Ordinary function invocation, or a chained series of calls.

src/lexer.coffee

@@ -258,6 +258,13 @@ exports.Lexer = class Lexer
     @token 'JS', (script = match[0])[1...-1], 0, script.length
     script.length
 
+  importToken: ->
+    match = @chunk.match(IMPORT)
+
+    return 0 unless match
+
+    @token('IMPORT', match[0], 0, match[0].length)
+
   # Matches regular expression literals, as well as multiline extended ones.
   # Lexing regular expressions is difficult to distinguish from division, so we
   # borrow some basic heuristics from JavaScript and Ruby.
@@ -774,7 +781,7 @@ JS_KEYWORDS = [
   'return', 'throw', 'break', 'continue', 'debugger', 'yield'
   'if', 'else', 'switch', 'for', 'while', 'do', 'try', 'catch', 'finally'
   'class', 'extends', 'super'
-  'export', 'import', 'default'
+  'export', 'import', 'from', 'default'
 ]
 
 # CoffeeScript-only keywords.
@@ -849,6 +856,8 @@ MULTI_DENT = /^(?:\n[^\n\S]*)+/
 
 JSTOKEN    = /^`[^\\`]*(?:\\.[^\\`]*)*`/
 
+IMPORT     = /^import .+/
+
 # String-matching-regexes.
 STRING_START   = /^(?:'''|"""|'|")/
 

src/nodes.coffee

@@ -1226,18 +1226,32 @@ exports.Class = class Class extends Base
 #### Import
 
 exports.Import = class Import extends Base
-  constructor: (@expression) ->
+  constructor: (@expression, @identifier) ->
 
-  children: ['expression']
+  children: ['expression', 'identifier']
 
   isStatement: YES
   jumps:       NO
 
   makeReturn: THIS
 
   compileNode: (o) ->
-    [].concat @makeCode(@tab + 'import '), @expression.compileToFragments(o), @makeCode(';')
+    code = []
+
+    code.push @makeCode(@tab + 'import ')
+
+
+    if @identifier
+      code.push @makeCode("#{@identifier.value} from ")
+
+
+    if @expression.base.value?
+      code.push @makeCode(@expression.base.value)
+    else
+      code.push @makeCode(@expression.base)
+    code.push @makeCode(';')
 
+    code
 
 #### Assign
 

test/modules.coffee

@@ -21,15 +21,15 @@ test "import module", ->
   # console.log toJS input
   eq toJS(input), output
 
-# test "module import test, syntax #1", ->
-#   input = "import foo from 'lib'"
-#   output = "import foo from 'lib';"
-#   eq toJS(input), output
+test "module import test, syntax #1", ->
+  input = "import foo from 'lib'"
+  output = "import foo from 'lib';"
+  eq toJS(input), output
 
-# test "module import test, syntax #2", ->
-#   input = "import { foo } from 'lib'"
-#   output = "import { foo } from 'lib';"
-#   eq toJS(input), output
+test "module import test, syntax #2", ->
+  input = "import { foo } from 'lib'"
+  output = "import { foo } from 'lib';"
+  eq toJS(input), output
 
 # test "module import test, syntax #3", ->
 #   input = "import { default as foo } from 'lib'"