Merge pull request #1788 from github/refactor-heuristics

Refactor heuristics (updated)
This commit is contained in:
Brandon Keepers
2014-11-28 17:59:43 -06:00
2 changed files with 128 additions and 209 deletions

View File

@@ -1,8 +1,6 @@
module Linguist
# A collection of simple heuristics that can be used to better analyze languages.
class Heuristics
ACTIVE = true
# Public: Use heuristics to detect language of the blob.
#
# blob - An object that quacks like a blob.
@@ -14,177 +12,123 @@ module Linguist
# Language["Ruby"], Language["Python"]
# ])
#
# Returns an Array with one Language if a heuristic matched, or empty if
# none matched or were inconclusive.
# Returns an Array of languages, or empty if none matched or were inconclusive.
def self.call(blob, languages)
find_by_heuristics(blob.data, languages.map(&:name))
end
data = blob.data
# Public: Given an array of String language names,
# apply heuristics against the given data and return an array
# of matching languages, or nil.
#
# data - Array of tokens or String data to analyze.
# languages - Array of language name Strings to restrict to.
#
# Returns an array of Languages or []
def self.find_by_heuristics(data, languages)
if active?
result = []
if languages.all? { |l| ["Perl", "Prolog"].include?(l) }
result = disambiguate_pl(data)
end
if languages.all? { |l| ["ECL", "Prolog"].include?(l) }
result = disambiguate_ecl(data)
end
if languages.all? { |l| ["IDL", "Prolog"].include?(l) }
result = disambiguate_pro(data)
end
if languages.all? { |l| ["Common Lisp", "OpenCL"].include?(l) }
result = disambiguate_cl(data)
end
if languages.all? { |l| ["Hack", "PHP"].include?(l) }
result = disambiguate_hack(data)
end
if languages.all? { |l| ["Scala", "SuperCollider"].include?(l) }
result = disambiguate_sc(data)
end
if languages.all? { |l| ["AsciiDoc", "AGS Script"].include?(l) }
result = disambiguate_asc(data)
end
if languages.all? { |l| ["FORTRAN", "Forth"].include?(l) }
result = disambiguate_f(data)
end
if languages.all? { |l| ["F#", "Forth", "GLSL"].include?(l) }
result = disambiguate_fs(data)
end
return result
@heuristics.each do |heuristic|
return Array(heuristic.call(data)) if heuristic.matches?(languages)
end
[] # No heuristics matched
end
# .h extensions are ambiguous between C, C++, and Objective-C.
# We want to shortcut look for Objective-C _and_ now C++ too!
# Internal: Define a new heuristic.
#
# Returns an array of Languages or []
def self.disambiguate_c(data)
matches = []
if data.include?("@interface")
matches << Language["Objective-C"]
elsif data.include?("#include <cstdint>")
matches << Language["C++"]
end
matches
# languages - String names of languages to disambiguate.
# heuristic - Block which takes data as an argument and returns a Language or nil.
#
# Examples
#
# disambiguate "Perl", "Prolog" do |data|
# if data.include?("use strict")
# Language["Perl"]
# elsif data.include?(":-")
# Language["Prolog"]
# end
# end
#
def self.disambiguate(*languages, &heuristic)
@heuristics << new(languages, &heuristic)
end
def self.disambiguate_pl(data)
matches = []
# Internal: Array of defined heuristics
@heuristics = []
# Internal
def initialize(languages, &heuristic)
@languages = languages
@heuristic = heuristic
end
# Internal: Check if this heuristic matches the candidate languages.
def matches?(candidates)
candidates.all? { |l| @languages.include?(l.name) }
end
# Internal: Perform the heuristic
def call(data)
@heuristic.call(data)
end
disambiguate "Perl", "Prolog" do |data|
if data.include?("use strict")
matches << Language["Perl"]
Language["Perl"]
elsif data.include?(":-")
matches << Language["Prolog"]
Language["Prolog"]
end
matches
end
def self.disambiguate_ecl(data)
matches = []
disambiguate "ECL", "Prolog" do |data|
if data.include?(":-")
matches << Language["Prolog"]
Language["Prolog"]
elsif data.include?(":=")
matches << Language["ECL"]
Language["ECL"]
end
matches
end
def self.disambiguate_pro(data)
matches = []
if (data.include?(":-"))
matches << Language["Prolog"]
disambiguate "IDL", "Prolog" do |data|
if data.include?(":-")
Language["Prolog"]
else
matches << Language["IDL"]
Language["IDL"]
end
matches
end
def self.disambiguate_ts(data)
matches = []
if (data.include?("</translation>"))
matches << Language["XML"]
else
matches << Language["TypeScript"]
end
matches
end
def self.disambiguate_cl(data)
matches = []
disambiguate "Common Lisp", "OpenCL" do |data|
if data.include?("(defun ")
matches << Language["Common Lisp"]
Language["Common Lisp"]
elsif /\/\* |\/\/ |^\}/.match(data)
matches << Language["OpenCL"]
Language["OpenCL"]
end
matches
end
def self.disambiguate_r(data)
matches = []
matches << Language["Rebol"] if /\bRebol\b/i.match(data)
matches << Language["R"] if data.include?("<-")
matches
end
def self.disambiguate_hack(data)
matches = []
disambiguate "Hack", "PHP" do |data|
if data.include?("<?hh")
matches << Language["Hack"]
Language["Hack"]
elsif /<?[^h]/.match(data)
matches << Language["PHP"]
Language["PHP"]
end
matches
end
def self.disambiguate_sc(data)
matches = []
if (/\^(this|super)\./.match(data) || /^\s*(\+|\*)\s*\w+\s*{/.match(data) || /^\s*~\w+\s*=\./.match(data))
matches << Language["SuperCollider"]
disambiguate "Scala", "SuperCollider" do |data|
if /\^(this|super)\./.match(data) || /^\s*(\+|\*)\s*\w+\s*{/.match(data) || /^\s*~\w+\s*=\./.match(data)
Language["SuperCollider"]
elsif /^\s*import (scala|java)\./.match(data) || /^\s*val\s+\w+\s*=/.match(data) || /^\s*class\b/.match(data)
Language["Scala"]
end
if (/^\s*import (scala|java)\./.match(data) || /^\s*val\s+\w+\s*=/.match(data) || /^\s*class\b/.match(data))
matches << Language["Scala"]
end
matches
end
def self.disambiguate_asc(data)
matches = []
matches << Language["AsciiDoc"] if /^=+(\s|\n)/.match(data)
matches
disambiguate "AsciiDoc", "AGS Script" do |data|
Language["AsciiDoc"] if /^=+(\s|\n)/.match(data)
end
def self.disambiguate_f(data)
matches = []
disambiguate "FORTRAN", "Forth" do |data|
if /^: /.match(data)
matches << Language["Forth"]
Language["Forth"]
elsif /^([c*][^a-z]| subroutine\s)/i.match(data)
matches << Language["FORTRAN"]
Language["FORTRAN"]
end
matches
end
def self.disambiguate_fs(data)
matches = []
disambiguate "F#", "Forth", "GLSL" do |data|
if /^(: |new-device)/.match(data)
matches << Language["Forth"]
Language["Forth"]
elsif /^(#light|import|let|module|namespace|open|type)/.match(data)
matches << Language["F#"]
Language["F#"]
elsif /^(#include|#pragma|precision|uniform|varying|void)/.match(data)
matches << Language["GLSL"]
Language["GLSL"]
end
matches
end
def self.active?
!!ACTIVE
end
end
end