Parse multiline

lib/hamlit/concerns/line_reader.rb

@@ -6,6 +6,10 @@ module Hamlit
         @current_lineno = -1
       end
 
+      def current_line
+        @lines[@current_lineno]
+      end
+
       # Return nearest line ignoring empty lines.
       def next_line
         lineno = @current_lineno + 1

lib/hamlit/engine.rb

@@ -1,12 +1,14 @@
 require 'temple'
 require 'hamlit/attribute_compiler'
-require 'hamlit/script_compiler'
+require 'hamlit/multiline_preprocessor'
 require 'hamlit/parser'
+require 'hamlit/script_compiler'
 
 module Hamlit
   class Engine < Temple::Engine
     define_options generator: Temple::Generators::ArrayBuffer
 
+    use MultilinePreprocessor
     use Parser
     use ScriptCompiler
     use AttributeCompiler

lib/hamlit/multiline_preprocessor.rb

@@ -0,0 +1,56 @@
+require 'temple'
+require 'hamlit/concerns/line_reader'
+
+module Hamlit
+  class MultilinePreprocessor < Temple::Parser
+    include Concerns::LineReader
+
+    def call(template)
+      reset_lines(template.split("\n"))
+      preprocess_multilines
+    end
+
+    private
+
+    def preprocess_multilines
+      result = []
+
+      while @lines[@current_lineno + 1]
+        @current_lineno += 1
+
+        if end_with_pipe?(current_line)
+          prefix = current_line[/\A */]
+          lines  = scan_multilines
+
+          result << prefix + build_multiline(lines)
+          (lines.length - 1).times { result << '' }
+        else
+          result << current_line
+        end
+      end
+      result.map { |line| "#{line}\n" }.join
+    end
+
+    def end_with_pipe?(line)
+      return false unless line
+      line.strip =~ / \|\Z/
+    end
+
+    def scan_multilines
+      lines = []
+      while end_with_pipe?(current_line)
+        lines << current_line
+        @current_lineno += 1
+      end
+      @current_lineno -= 1
+      lines
+    end
+
+    def build_multiline(lines)
+      lines = lines.map do |line|
+        line.strip.gsub(/ *\|\Z/, '')
+      end
+      lines.join(' ')
+    end
+  end
+end

lib/hamlit/parser.rb

@@ -39,7 +39,7 @@ module Hamlit
       ast = []
       while next_indent == @current_indent
         @current_lineno += 1
-        ast << parse_line(@lines[@current_lineno])
+        ast << parse_line(current_line)
         ast << [:static, "\n"] unless skip_newline?(ast.last)
         ast << [:newline]
       end

spec/hamlit/engine/multiline_spec.rb

@@ -0,0 +1,24 @@
+describe Hamlit::Engine do
+  describe 'multiline' do
+    it 'joins multi-lines ending with pipe' do
+      assert_render(<<-HAML, <<-HTML)
+        a |
+          b |
+      HAML
+        a b
+      HTML
+    end
+
+    it 'renders multi lines' do
+      assert_render(<<-HAML, <<-HTML)
+        = 'a' +  |
+             'b' + |
+             'c' |
+        'd'
+      HAML
+        abc
+        'd'
+      HTML
+    end
+  end
+end

spec/hamlit/multiline_preprocessor_spec.rb

@@ -0,0 +1,42 @@
+describe Hamlit::MultilinePreprocessor do
+  describe '#call' do
+    def assert_multiline_preprocess(before, after)
+      result = described_class.new.call(before)
+      expect(result).to eq(after)
+    end
+
+    it 'does not alter normal lines' do
+      assert_multiline_preprocess(<<-HAML, <<-HAML)
+        abc
+        d|
+        ef
+      HAML
+        abc
+        d|
+        ef
+      HAML
+    end
+
+    it 'joins multi-lines' do
+      assert_multiline_preprocess(<<-HAML, <<-HAML)
+        abc  |
+        d    |
+        ef
+      HAML
+        abc d
+
+        ef
+      HAML
+    end
+
+    it 'joins multi-lines' do
+      assert_multiline_preprocess(<<-HAML, <<-HAML)
+        = 'a' + |
+            'b' |
+      HAML
+        = 'a' + 'b'
+
+      HAML
+    end
+  end
+end