Class: Remind::Session

Inherits:
Object
  • Object
show all
Defined in:
lib/remind/session.rb

Overview

A live Remind interpreter.

Remind is a program, not a library, and it shows in the shape of the C: today's date is a global, the current time is a global, and everything is computed against whatever those say. That has two consequences.

The first is a gift: "now" is settable, so a calculation against a fixed date is reproducible rather than a reading off the clock. Converting a reminder file to a calendar depends on it -- REM Mon means a different first date tomorrow than it does today.

The second is that the state is per-process, not per-object. Two Sessions are two views of the same globals, so the lock is on the class and calls into the library are serialised whether they came from one Session or several.

Constant Summary collapse

LOCK = 
Mutex.new
NO_TIME = 
-1
SECONDS_PER_MINUTE = 
60

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(native: Native.new, diagnostics: false) ⇒ Session

Returns a new instance of Session.



49
50
51
52
53
 
# File 'lib/remind/session.rb', line 49

def initialize(native: Native.new, diagnostics: false)
  @native = native

  Runtime.boot(native, diagnostics: diagnostics)
end

Instance Attribute Details

#native ⇒ Object (readonly)

Returns the value of attribute native.



47
48
49
 
# File 'lib/remind/session.rb', line 47

def native
  @native
end

Instance Method Details

#date(dse) ⇒ Object 



99
100
101
 
# File 'lib/remind/session.rb', line 99

def date(dse)
  Value.to_date(dse, native)
end

#diagnostics=(wanted) ⇒ Object

Whether Remind prints its own diagnostics -- the offending line with a caret under it -- as well as this raising.



105
106
107
108
109
 
# File 'lib/remind/session.rb', line 105

def diagnostics=(wanted)
  LOCK.synchronize do
    Runtime.point_errors(native, wanted)
  end
end

#dse(date) ⇒ Object

Remind's day count for a date, and back again.



95
96
97
 
# File 'lib/remind/session.rb', line 95

def dse(date)
  native.dse(date.year, date.month - 1, date.day)
end

#error_message(code) ⇒ Object 



117
118
119
 
# File 'lib/remind/session.rb', line 117

def error_message(code)
  native.error_message(code).to_s
end

#evaluate(expression) ⇒ Object

Evaluates a Remind expression: an Integer for a number, a String for a string, a Date for a date, a Time for a datetime, minutes since midnight for a time.

session.evaluate("moonphase(today())")   # => 46
session.evaluate("version()")            # => "06.02.10"


61
62
63
64
65
 
# File 'lib/remind/session.rb', line 61

def evaluate(expression)
  LOCK.synchronize do
    evaluate_unlocked(expression)
  end
end

#now=(time) ⇒ Object

Pins the date and the time of day together, for reminders that depend on the clock as well as the calendar.



81
82
83
84
85
86
 
# File 'lib/remind/session.rb', line 81

def now=(time)
  LOCK.synchronize do
    pin_date(time.to_date)
    pin_time((time.hour * 60) + time.min)
  end
end

#today ⇒ Object

The date every relative calculation is relative to.



68
69
70
 
# File 'lib/remind/session.rb', line 68

def today
  date(native.read_global("DSEToday"))
end

#today=(date) ⇒ Object

Pins it, the way remind --date= does.



73
74
75
76
77
 
# File 'lib/remind/session.rb', line 73

def today=(date)
  LOCK.synchronize do
    pin_date(date)
  end
end

#unpin_time ⇒ Object 



88
89
90
91
92
 
# File 'lib/remind/session.rb', line 88

def unpin_time
  LOCK.synchronize do
    pin_time(nil)
  end
end

#version ⇒ Object

The Remind release the library was built from, out of the library's own version() rather than out of this gem's idea of it.



113
114
115
 
# File 'lib/remind/session.rb', line 113

def version
  evaluate("version()")
end