@import causes com.github.sommeri.less4j.core.problems.BugHappened

[DanielSvanstrom]

We tried a less compilation with an imported file and received a com.github.sommeri.less4j.core.problems.BugHappened while running it. The test case is very simple. In the less file we want to compile we start with a @import "anotherLessFile";
In the imported file we have some correct regular css code (can actually be an empty file) and there does not need to be any other content in the main less file.

This was tested on the standalone version of less4j 0.0.8, java version 1.7.0_10.

We get the following output:
Exception in thread "main" com.github.sommeri.less4j.core.problems.BugHappened: Bug, please report issue: Unexpected token type: 47(IMPORT_SYM) for @import
Offending place: 1:1
at com.github.sommeri.less4j.core.parser.TokenTypeSwitch.switchOn(TokenTypeSwitch.java:132)
at com.github.sommeri.less4j.core.parser.ASTBuilderSwitch.handleStyleSheet(ASTBuilderSwitch.java:94)
at com.github.sommeri.less4j.core.parser.ASTBuilderSwitch.handleStyleSheet(ASTBuilderSwitch.java:68)
at com.github.sommeri.less4j.core.parser.TokenTypeSwitch.switchOn(TokenTypeSwitch.java:37)
at com.github.sommeri.less4j.core.parser.ASTBuilder.parse(ASTBuilder.java:24)
at com.github.sommeri.less4j.core.ThreadUnsafeLessCompiler.doCompile(ThreadUnsafeLessCompiler.java:40)
at com.github.sommeri.less4j.core.ThreadUnsafeLessCompiler.compile(ThreadUnsafeLessCompiler.java:25)
at com.github.sommeri.less4j.core.DefaultLessCompiler.compile(DefaultLessCompiler.java:11)
at com.github.sommeri.less4j.commandline.CommandLine.compile(CommandLine.java:186)
at com.github.sommeri.less4j.commandline.CommandLine.runAsSinglemode(CommandLine.java:80)
at com.github.sommeri.less4j.commandline.CommandLine.realMain(CommandLine.java:68)
at com.github.sommeri.less4j.commandline.CommandLine.main(CommandLine.java:32)

[SomMeri]

Import feature has not been implemented yet. I will bump up its priority, it seems to be important to multiple people.

[SomMeri]

I will keep the progress and analysis in #19 - I'm not sure yet how less.js importing works, so if you know about it or have some need that should be treated as a priority, you can comment there.

[SomMeri]

First version of simple top level only import is done and documented on wiki: https://github.com/SomMeri/less4j/wiki/Less-Language-Import .

It supports all three import statements: import, import-once, import-multiple. Since less.js 1.4.0 will change the meaning of @import, I would recommend to use either import-once or import-multiple.