core/interpreter.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 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 |
import streams, strutils, critbits import types, parser, scope, ../vendor/linenoise const ERRORS: array [MinError, string] = [ "A system error occurred", "A parsing error occurred", "A generic error occurred", "Insufficient items on the stack", "Quotation not found on the stack", "Symbol undefined", "Incorrect items on the stack", "Two numbers are required on the stack", "Division by zero" ] var ROOT*: MinScope proc newMinInterpreter*(debugging = false): MinInterpreter = var s:MinStack = newSeq[MinValue](0) var p:MinParser var i:MinInterpreter = MinInterpreter(filename: "input", parser: p, stack: s, debugging: debugging, currSym: MinValue(column: 1, line: 1, kind: minSymbol, symVal: "")) return i proc error*(i: MinInterpreter, status: MinError, message = "") = var msg = if message == "": ERRORS[status] else: message if i.filename == "": stderr.writeLine("`$1`: Error - $2" % [i.currSym.symVal, msg]) else: stderr.writeLine("$1 [$2,$3] `$4`: Error - $5" % [i.filename, $i.currSym.line, $i.currSym.column, i.currSym.symVal, msg]) quit(int(status)) proc open*(i: var MinInterpreter, stream:Stream, filename: string) = i.filename = filename i.parser.open(stream, filename) proc close*(i: var MinInterpreter) = i.parser.close(); proc dump*(i: MinInterpreter): string = var s = "" for item in i.stack: s = s & $item & " " return s proc debug(i: var MinInterpreter, value: MinValue) = if i.debugging: stderr.writeLine("-- " & i.dump & $value) proc push*(i: var MinInterpreter, val: MinValue) = i.debug val if val.kind == minSymbol: if not i.evaluating: i.currSym = val let symbol = val.symVal let sigil = "" & symbol[0] if ROOT.symbols.hasKey(val.symVal): try: ROOT.symbols[val.symVal](i) except: i.error(errSystem, getCurrentExceptionMsg()) else: if ROOT.sigils.hasKey(sigil) and symbol.len > 1: let sym = symbol[1..symbol.len-1] try: i.stack.add(MinValue(kind: minString, strVal: sym)) ROOT.sigils[sigil](i) except: i.error(errSystem, getCurrentExceptionMsg()) else: i.error(errUndefined, "Undefined symbol: '"&val.symVal&"'") else: i.stack.add(val) proc push*(i: var MinInterpreter, q: seq[MinValue]) = for e in q: i.push e proc pop*(i: var MinInterpreter): MinValue = if i.stack.len > 0: return i.stack.pop else: i.error(errEmptyStack) proc peek*(i: MinInterpreter): MinValue = if i.stack.len > 0: return i.stack[i.stack.len-1] else: i.error(errEmptyStack) proc interpret*(i: var MinInterpreter) = var val: MinValue while i.parser.token != tkEof: try: val = i.parser.parseMinValue except: i.error errParser, getCurrentExceptionMsg() i.push val proc eval*(i: var MinInterpreter, s: string) = let fn = i.filename try: i.open(newStringStream(s), "eval") discard i.parser.getToken() i.interpret() except: stderr.writeLine getCurrentExceptionMsg() finally: i.filename = fn proc load*(i: var MinInterpreter, s: string) = let fn = i.filename try: i.open(newStringStream(s.readFile), s) discard i.parser.getToken() i.interpret() except: stderr.writeLine getCurrentExceptionMsg() finally: i.filename = fn proc apply*(i: var MinInterpreter, symbol: string) = ROOT.symbols[symbol](i) proc copystack*(i: var MinInterpreter): MinStack = var s = newSeq[MinValue](0) for i in i.stack: s.add i return s |