all repos — min @ 48eee1341d8e9a7f6b6f3bbfa98495675d24f672

A small but practical concatenative programming language.

core/scope.nim

 1
 2
 3
 4
 5
 6
 7
 8
 9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 
import
  strutils,
  critbits
import
  parser

proc copy*(s: ref MinScope): ref MinScope {.extern:"min_exported_symbol_$1".}=
  var scope = newScope(s.parent)
  scope.symbols = s.symbols
  new(result)
  result[] = scope
  
proc getSymbol*(scope: ref MinScope, key: string): MinOperator {.extern:"min_exported_symbol_$1".}=
  if scope.symbols.hasKey(key):
    return scope.symbols[key]
  elif not scope.parent.isNil:
    return scope.parent.getSymbol(key)
  else:
    raiseUndefined("Symbol '$1' not found." % key)

proc hasSymbol*(scope: ref MinScope, key: string): bool {.extern:"min_exported_symbol_$1".}=
  if scope.isNil:
    return false
  elif scope.symbols.hasKey(key):
    return true
  elif not scope.parent.isNil:
    return scope.parent.hasSymbol(key)
  else:
    return false

proc delSymbol*(scope: ref MinScope, key: string): bool {.discardable, extern:"min_exported_symbol_$1".}=
  if scope.symbols.hasKey(key):
    if scope.symbols[key].sealed:
      raiseInvalid("Symbol '$1' is sealed." % key) 
    scope.symbols.excl(key)
    return true
  return false

proc setSymbol*(scope: ref MinScope, key: string, value: MinOperator, override = false): bool {.discardable, extern:"min_exported_symbol_$1".}=
  result = false
  # check if a symbol already exists in current scope
  if not scope.isNil and scope.symbols.hasKey(key):
    if not override and scope.symbols[key].sealed:
      raiseInvalid("Symbol '$1' is sealed." % key) 
    scope.symbols[key] = value
    result = true
  else:
    # Go up the scope chain and attempt to find the symbol
    if not scope.parent.isNil:
      result = scope.parent.setSymbol(key, value)

proc getSigil*(scope: ref MinScope, key: string): MinOperator {.extern:"min_exported_symbol_$1".}=
  if scope.sigils.hasKey(key):
    return scope.sigils[key]
  elif not scope.parent.isNil:
    return scope.parent.getSigil(key)
  else:
    raiseUndefined("Sigil '$1' not found." % key)

proc hasSigil*(scope: ref MinScope, key: string): bool {.extern:"min_exported_symbol_$1".}=
  if scope.isNil:
    return false
  elif scope.sigils.hasKey(key):
    return true
  elif not scope.parent.isNil:
    return scope.parent.hasSigil(key)
  else:
    return false

proc previous*(scope: ref MinScope): ref MinScope {.extern:"min_exported_symbol_$1".}=
  if scope.parent.isNil:
    return scope 
  else:
    return scope.parent