Created
April 22, 2012 20:07
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Lua scanner for CodeRay
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diff --git a/lib/coderay/scanners/lua.rb b/lib/coderay/scanners/lua.rb | |
new file mode 100644 | |
index 0000000..e7706fc | |
--- /dev/null | |
+++ b/lib/coderay/scanners/lua.rb | |
@@ -0,0 +1,267 @@ | |
+# -*- coding: utf-8 -*- | |
+ | |
+# Scanner for the Lua[http://lua.org] programming lanuage. | |
+# | |
+# The language’s complete syntax is defined in | |
+# {the Lua manual}[http://www.lua.org/manual/5.2/manual.html], | |
+# which is what this scanner tries to conform to. | |
+class CodeRay::Scanners::Lua < CodeRay::Scanners::Scanner | |
+ | |
+ register_for :lua | |
+ file_extension "lua" | |
+ title "Lua" | |
+ | |
+ # Keywords used in Lua. | |
+ KEYWORDS = %w[and break do else elseif end | |
+ for function goto if in | |
+ local not or repeat return | |
+ then until while | |
+ ] | |
+ | |
+ # Constants set by the Lua core. | |
+ PREDEFINED_CONSTANTS = %w[false true nil] | |
+ | |
+ # The expressions contained in this array are parts of Lua’s `basic' | |
+ # library. Although it’s not entirely necessary to load that library, | |
+ # it is highly recommended and one would have to provide own implementations | |
+ # of some of these expressions if one does not do so. They however aren’t | |
+ # keywords, neither are they constants, but nearly predefined, so they | |
+ # get tagged as `predefined' rather than anything else. | |
+ # | |
+ # This list excludes values of form `_UPPERCASE' because the Lua manual | |
+ # requires such identifiers to be reserved by Lua anyway and they are | |
+ # highlighted directly accordingly, without the need for specific | |
+ # identifiers to be listed here. | |
+ PREDEFINED_EXPRESSIONS = %w[ | |
+ assert collectgarbage dofile error getmetatable | |
+ ipairs load loadfile next pairs pcall print | |
+ rawequal rawget rawlen rawset select setmetatable | |
+ tonumber tostring type xpcall | |
+ ] | |
+ | |
+ # Automatic token kind selection for normal words. | |
+ IDENT_KIND = CodeRay::WordList.new(:ident) | |
+ .add(KEYWORDS, :keyword) | |
+ .add(PREDEFINED_CONSTANTS, :predefined_constant) | |
+ .add(PREDEFINED_EXPRESSIONS, :predefined) | |
+ | |
+ protected | |
+ | |
+ # Scanner initialization. | |
+ def setup | |
+ @state = :initial | |
+ @brace_depth = 0 | |
+ end | |
+ | |
+ # CodeRay entry hook. Starts parsing. | |
+ def scan_tokens(encoder, options) | |
+ @encoder = encoder | |
+ @options = options | |
+ | |
+ send(:"handle_state_#@state") until eos? | |
+ | |
+ @encoder | |
+ end | |
+ | |
+ def handle_state_initial | |
+ if match = scan(/\-\-\[\=*\[/) #--[[ long (possibly multiline) comment ]] | |
+ @num_equals = match.count("=") # Number must match for comment end | |
+ @encoder.begin_group(:comment) | |
+ @encoder.text_token(match, :delimiter) | |
+ @state = :long_comment | |
+ | |
+ elsif match = scan(/--.*?$/) # --Lua comment | |
+ @encoder.text_token(match, :comment) | |
+ | |
+ elsif match = scan(/\[=*\[/) # [[ long (possibly multiline) string ]] | |
+ @num_equals = match.count("=") # Number must match for comment end | |
+ @encoder.begin_group(:string) | |
+ @encoder.text_token(match, :delimiter) | |
+ @state = :long_string | |
+ | |
+ elsif match = scan(/::\s*[a-zA-Z_][a-zA-Z0-9_]+\s*::/) # ::goto_label:: | |
+ @encoder.text_token(match, :label) | |
+ | |
+ elsif match = scan(/_[A-Z]+/) # _UPPERCASE are names reserved for Lua | |
+ @encoder.text_token(match, :predefined) | |
+ | |
+ elsif match = scan(/[a-zA-Z_][a-zA-Z0-9_]*/) # Normal letters (or letters followed by digits) | |
+ kind = IDENT_KIND[match] | |
+ | |
+ # Extra highlighting for entities following certain keywords | |
+ if kind == :keyword and match == "function" | |
+ @state = :function_expected | |
+ elsif kind == :keyword and match == "goto" | |
+ @state = :goto_label_expected | |
+ elsif kind == :keyword and match == "local" | |
+ @state = :local_var_expected | |
+ end | |
+ | |
+ @encoder.text_token(match, kind) | |
+ | |
+ elsif match = scan(/{/) # Opening table brace { | |
+ @encoder.begin_group(:table) | |
+ @encoder.text_token(match, @brace_depth >= 1 ? :inline_delimiter : :delimiter) | |
+ @brace_depth += 1 | |
+ @state = :table | |
+ | |
+ elsif match = scan(/}/) # Closing table brace } | |
+ if @brace_depth == 1 | |
+ @brace_depth = 0 | |
+ @encoder.text_token(match, :delimiter) | |
+ elsif @brace_depth == 0 # Mismatched brace | |
+ @encoder.text_token(match, :error) | |
+ else | |
+ @brace_depth -= 1 | |
+ @encoder.text_token(match, :inline_delimiter) | |
+ @state = :table | |
+ end | |
+ @encoder.end_group(:table) | |
+ | |
+ elsif match = scan(/["']/) # String delimiters " and ' | |
+ @encoder.begin_group(:string) | |
+ @encoder.text_token(match, :delimiter) | |
+ @start_delim = match | |
+ @state = :string | |
+ | |
+ # ↓Prefix hex number ←|→ decimal number | |
+ elsif match = scan(/-? (?:0x\h* \. \h+ (?:p[+\-]?\d+)? | \d*\.\d+ (?:e[+\-]?\d+)?)/ix) # hexadecimal constants have no E power, decimal ones no P power | |
+ @encoder.text_token(match, :float) | |
+ | |
+ # ↓Prefix hex number ←|→ decimal number | |
+ elsif match = scan(/-? (?:0x\h+ (?:p[+\-]?\d+)? | \d+ (?:e[+\-]?\d+)?)/ix) # hexadecimal constants have no E power, decimal ones no P power | |
+ @encoder.text_token(match, :integer) | |
+ | |
+ elsif match = scan(/[\+\-\*\/%^\#=~<>\(\)\[\]:;,] | \.(?!\d)/x) # Operators | |
+ @encoder.text_token(match, :operator) | |
+ | |
+ elsif match = scan(/\s+/) # Space | |
+ @encoder.text_token(match, :space) | |
+ | |
+ else # Invalid stuff. Note that Lua doesn’t accept multibyte chars outside of strings, hence these are also errors. | |
+ @encoder.text_token(getch, :error) | |
+ end | |
+ | |
+ # It may be that we’re scanning a full-blown subexpression of a table | |
+ # (tables can contain full expressions in parts). | |
+ # If this is the case, return to :table scanning state. | |
+ @state = :table if @state == :initial && @brace_depth >= 1 | |
+ end | |
+ | |
+ def handle_state_function_expected | |
+ if match = scan(/\(.*?\)/m) # x = function() # "Anonymous" function without explicit name | |
+ @encoder.text_token(match, :operator) | |
+ @state = :initial | |
+ elsif match = scan(/[a-zA-Z_] (?:[a-zA-Z0-9_\.] (?!\.\d))* [\.\:]/x) # function tbl.subtbl.foo() | function tbl:foo() # Colon only allowed as last separator | |
+ @encoder.text_token(match, :ident) | |
+ elsif match = scan(/[a-zA-Z_][a-zA-Z0-9_]*/) # function foo() | |
+ @encoder.text_token(match, :function) | |
+ @state = :initial | |
+ elsif match = scan(/\s+/) # Between the `function' keyword and the ident may be any amount of whitespace | |
+ @encoder.text_token(match, :space) | |
+ else | |
+ @encoder.text_token(getch, :error) | |
+ @state = :initial | |
+ end | |
+ end | |
+ | |
+ def handle_state_goto_label_expected | |
+ if match = scan(/[a-zA-Z_][a-zA-Z0-9_]*/) | |
+ @encoder.text_token(match, :label) | |
+ @state = :initial | |
+ elsif match = scan(/\s+/) # Between the `goto' keyword and the label may be any amount of whitespace | |
+ @encoder.text_token(match, :space) | |
+ else | |
+ @encoder.text_token(getch, :error) | |
+ end | |
+ end | |
+ | |
+ def handle_state_local_var_expected | |
+ if match = scan(/function/) # local function ... | |
+ @encoder.text_token(match, :keyword) | |
+ @state = :function_expected | |
+ elsif match = scan(/[a-zA-Z_][a-zA-Z0-9_]*/) | |
+ @encoder.text_token(match, :local_variable) | |
+ elsif match = scan(/,/) | |
+ @encoder.text_token(match, :operator) | |
+ elsif match = scan(/=/) | |
+ @encoder.text_token(match, :operator) | |
+ # After encountering the equal sign, arbitrary expressions are | |
+ # allowed again, so just return to the main state for further | |
+ # parsing. | |
+ @state = :initial | |
+ elsif match = scan(/\n/) | |
+ @encoder.text_token(match, :space) | |
+ @state = :initial | |
+ elsif match = scan(/\s+/) | |
+ @encoder.text_token(match, :space) | |
+ else | |
+ @encoder.text_token(getch, :error) | |
+ end | |
+ end | |
+ | |
+ def handle_state_long_comment | |
+ if match = scan(/.*?(?=\]={#@num_equals}\])/m) | |
+ @encoder.text_token(match, :content) | |
+ | |
+ delim = scan(/\]={#@num_equals}\]/) | |
+ @encoder.text_token(delim, :delimiter) | |
+ else # No terminator found till EOF | |
+ @encoder.text_token(rest, :error) | |
+ terminate | |
+ end | |
+ @encoder.end_group(:comment) | |
+ @state = :initial | |
+ end | |
+ | |
+ def handle_state_long_string | |
+ if match = scan(/.*?(?=\]={#@num_equals}\])/m) # Long strings do not interpret any escape sequences | |
+ @encoder.text_token(match, :content) | |
+ | |
+ delim = scan(/\]={#@num_equals}\]/) | |
+ @encoder.text_token(delim, :delimiter) | |
+ else # No terminator found till EOF | |
+ @encoder.text_token(rest, :error) | |
+ terminate | |
+ end | |
+ @encoder.end_group(:string) | |
+ @state = :initial | |
+ end | |
+ | |
+ def handle_state_string | |
+ if match = scan(/[^\\#@start_delim\n]+/) # Everything except \ and the start delimiter character is string content (newlines are only allowed if preceeded by \ or \z) | |
+ @encoder.text_token(match, :content) | |
+ elsif match = scan(/\\(?:['"abfnrtv\\]|z\s*|x\h\h|\d{1,3}|\n)/m) | |
+ @encoder.text_token(match, :char) | |
+ elsif match = scan(Regexp.compile(@start_delim)) | |
+ @encoder.text_token(match, :delimiter) | |
+ @encoder.end_group(:string) | |
+ @state = :initial | |
+ elsif match = scan(/\n/) # Lua forbids unescaped newlines in normal non-long strings | |
+ @encoder.text_token("\\n\n", :error) # Visually appealing error indicator--otherwise users may wonder whether the highlighter cannot highlight multine strings | |
+ @encoder.end_group(:string) | |
+ @state = :initial | |
+ else | |
+ @encoder.text_token(getch, :error) | |
+ end | |
+ end | |
+ | |
+ def handle_state_table | |
+ if match = scan(/[,;]/) | |
+ @encoder.text_token(match, :operator) | |
+ elsif match = scan(/[a-zA-Z_][a-zA-Z0-9_]* (?=\s*=)/x) | |
+ @encoder.text_token(match, :key) | |
+ @encoder.text_token(scan(/\s+/), :space) if check(/\s+/) | |
+ @encoder.text_token(scan(/=/), :operator) | |
+ @state = :initial | |
+ elsif match = scan(/\s+/m) | |
+ @encoder.text_token(match, :space) | |
+ else | |
+ # Note this clause doesn’t advance the scan pointer, it’s a kind of | |
+ # "retry with other options" (the :initial state then of course | |
+ # advances the pointer). | |
+ @state = :initial | |
+ end | |
+ end | |
+ | |
+end | |
diff --git a/lib/coderay/styles/alpha.rb b/lib/coderay/styles/alpha.rb | |
index 8506d10..257083e 100644 | |
--- a/lib/coderay/styles/alpha.rb | |
+++ b/lib/coderay/styles/alpha.rb | |
@@ -116,6 +116,9 @@ table.CodeRay td { padding: 2px 4px; vertical-align: top; } | |
.symbol .content { color:#A60 } | |
.symbol .delimiter { color:#630 } | |
.symbol { color:#A60 } | |
+.table .content { color:#808 } | |
+.table .delimiter { color:#40A} | |
+.table { background-color:hsla(200,100%,50%,0.06); } | |
.tag { color:#070 } | |
.type { color:#339; font-weight:bold } | |
.value { color: #088; } | |
diff --git a/lib/coderay/token_kinds.rb b/lib/coderay/token_kinds.rb | |
index 3b8d07e..e245623 100755 | |
--- a/lib/coderay/token_kinds.rb | |
+++ b/lib/coderay/token_kinds.rb | |
@@ -63,6 +63,7 @@ module CodeRay | |
:shell => 'shell', | |
:string => 'string', | |
:symbol => 'symbol', | |
+ :table => 'table', | |
:tag => 'tag', | |
:type => 'type', | |
:value => 'value', |
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