So, I making toy-programming language on JS and I met one trouble... namely in labels. According to my idea, everything that comes after the label is entered into the object and later runs when necessary code:
var OBJcode = {}
labels = {}
code = `zhopa: i am string
i am string
i am string
i am string`
CodeLine = code.split("\n")
for (var i = 0; i < CodeLine.length; i++) {
runCode = CodeLine[i].split(" ")
OBJcode[i] = runCode
label = runCode[0]
instruction = CodeLine[1]
src = runCode[2]
dst = runCode[3]
if (`${dst}` == "undefined") {
dst = src
src = instruction
instruction = label
}
if (label.endsWith(":")) labels[label.slice(0, -1)] += CodeLine[i + 1].split(" ").join(" ")
}
console.log(code)
console.log(OBJcode)
console.log(labels)output:
zhopa: i am string
i am string
i am string
i am string {
'0': ['zhopa:', 'i', 'am', 'string'],
'1': ['i', 'am', 'string'],
'2': ['i', 'am', 'string'],
'3': ['i', 'am', 'string']
} {
zhopa: 'undefinedi am string'
}
And how to add next lines to labels[label]?
most likely the problem is at 21:56
The first time you do
labels[label.slice(0, -1)] += CodeLine[i + 1].split(" ").join(" ")
the labels object is empty, so labels[label.slice(0, -1)] is undefined. When you concatenate to this, it converts the undefined value to the string "undefined", and then CodeLine[i + 1].split(" ").join(" ") is appended to this. So you get undefined at the beginning of the result.
You need to check if the object property exists or not before concatenating.
var OBJcode = {}
labels = {}
code = `zhopa: i am string
i am string
i am string
i am string`
CodeLine = code.split("\n")
for (var i = 0; i < CodeLine.length; i++) {
runCode = CodeLine[i].split(" ")
OBJcode[i] = runCode
label = runCode[0]
instruction = CodeLine[1]
src = runCode[2]
dst = runCode[3]
if (`${dst}` == "undefined") {
dst = src
src = instruction
instruction = label
}
if (label.endsWith(":")) {
let key = label.slice(0, -1);
let value = CodeLine[i + 1].split(" ").join(" ");
if (labels[key]) {
labels[key] += value;
} else {
labels[key] = value;
}
}
}
console.log(code)
console.log(OBJcode)
console.log(labels)