HPR1128: Compilers part4

Summary: In this episode sigflup describes the construction of a calculator using lexical analysis and parsing. Figure A: https://devio.us/~sigflup/compiler/figa.jpg Figure B: https://devio.us/~sigflup/compiler/figb.jpg Figure C: https://devio.us/~sigflup/compiler/figc.jpg Figure D: https://devio.us/~sigflup/compiler/figd.jpg Figure E: https://devio.us/~sigflup/compiler/fige.jpg Figure F: https://devio.us/~sigflup/compiler/figf.jpg Figure G: https://devio.us/~sigflup/compiler/figg.jpg