import { byte, word, Memory } from 'js/types'; import { toHex } from 'js/util'; import { CURLINE, ARG, FAC, ARYTAB, STREND, TXTTAB, VARTAB } from './zeropage'; export type ApplesoftValue = word | number | string | ApplesoftArray; export type ApplesoftArray = Array; export enum VariableType { Float = 0, String = 1, Function = 2, Integer = 3 } export interface ApplesoftVariable { name: string; sizes?: number[]; type: VariableType; value: ApplesoftValue | undefined; } export class ApplesoftHeap { constructor(private mem: Memory) {} private readByte(addr: word): byte { const page = addr >> 8; const off = addr & 0xff; if (page >= 0xc0) { throw new Error(`Address ${toHex(page)} out of range`); } return this.mem.read(page, off); } private readWord(addr: word): word { const lsb = this.readByte(addr); const msb = this.readByte(addr + 1); return (msb << 8) | lsb; } private readInt(addr: word): word { const msb = this.readByte(addr); const lsb = this.readByte(addr + 1); return (msb << 8) | lsb; } private readFloat(addr: word, { unpacked } = { unpacked: false }): number { let exponent = this.readByte(addr); if (exponent === 0) { return 0; } exponent = (exponent & 0x80 ? 1 : -1) * ((exponent & 0x7F) - 1); let msb = this.readByte(addr + 1); const sb3 = this.readByte(addr + 2); const sb2 = this.readByte(addr + 3); const lsb = this.readByte(addr + 4); let sign; if (unpacked) { const sb = this.readByte(addr + 5); sign = sb & 0x80 ? -1 : 1; } else { sign = msb & 0x80 ? -1 : 1; } msb &= 0x7F; const mantissa = (msb << 24) | (sb3 << 16) | (sb2 << 8) | lsb; return sign * (1 + mantissa / 0x80000000) * Math.pow(2, exponent); } private readString(len: byte, addr: word): string { let str = ''; for (let idx = 0; idx < len; idx++) { str += String.fromCharCode(this.readByte(addr + idx) & 0x7F); } return str; } private readVar(addr: word) { const firstByte = this.readByte(addr); const lastByte = this.readByte(addr + 1); const firstLetter = firstByte & 0x7F; const lastLetter = lastByte & 0x7F; const name = String.fromCharCode(firstLetter) + (lastLetter ? String.fromCharCode(lastLetter) : ''); const type = (lastByte & 0x80) >> 7 | (firstByte & 0x80) >> 6; return { name, type }; } private readArray(addr: word, type: byte, sizes: number[]): ApplesoftArray { let strLen, strAddr; let value; const ary = []; const len = sizes[0]; for (let idx = 0; idx < len; idx++) { if (sizes.length > 1) { value = this.readArray(addr, type, sizes.slice(1)); } else { switch (type) { case 0: // Real value = this.readFloat(addr); addr += 5; break; case 1: // String strLen = this.readByte(addr); strAddr = this.readWord(addr + 1); value = this.readString(strLen, strAddr); addr += 3; break; case 3: // Integer default: value = this.readInt(addr); addr += 2; break; } } ary[idx] = value; } return ary; } dumpInternals() { return { txttab: this.readWord(TXTTAB), fac: this.readFloat(FAC, { unpacked: true }), arg: this.readFloat(ARG, { unpacked: true }), curline: this.readWord(CURLINE), }; } dumpVariables() { const simpleVariableTable = this.readWord(VARTAB); const arrayVariableTable = this.readWord(ARYTAB); const variableStorageEnd = this.readWord(STREND); // var stringStorageStart = readWord(0x6F); let addr; const vars: ApplesoftVariable[] = []; let value; let strLen, strAddr; for (addr = simpleVariableTable; addr < arrayVariableTable; addr += 7) { const { name, type } = this.readVar(addr); switch (type) { case VariableType.Float: value = this.readFloat(addr + 2); break; case VariableType.String: strLen = this.readByte(addr + 2); strAddr = this.readWord(addr + 3); value = this.readString(strLen, strAddr); break; case VariableType.Function: value = toHex(this.readWord(addr + 2)); value += ',' + toHex(this.readWord(addr + 4)); break; case VariableType.Integer: value = this.readInt(addr + 2); break; } vars.push({ name, type, value }); } while (addr < variableStorageEnd) { const { name, type } = this.readVar(addr); const off = this.readWord(addr + 2); const dim = this.readByte(addr + 4); const sizes = []; for (let idx = 0; idx < dim; idx++) { sizes[idx] = this.readInt(addr + 5 + idx * 2); } value = this.readArray(addr + 5 + dim * 2, type, sizes); vars.push({ name, sizes, type, value }); if (off < 1) { break; } addr += off; } return vars; } }