Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Lua scanner for CodeRay. Meta-commit.
This commit is a super-commit containing all the subcommits for implementing the Lua scanner.
- Loading branch information
Quintus
committed
Apr 22, 2012
1 parent
359db45
commit 501df76
Showing
3 changed files
with
271 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -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 |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters