working parentheses parsing

This commit is contained in:
minjaesong
2020-06-09 03:22:19 +09:00
parent 2eb6a4a99e
commit 7b9fcfbaf9

View File

@@ -84,7 +84,7 @@ function BasicAST() {
this.depth = 0;
this.leaves = [];
this.value = undefined;
this.type = "null"; // literal, operator, variable, function
this.type = "null"; // literal, operator, variable, function, null
this.toString = function() {
var sb = "";
@@ -162,6 +162,10 @@ basicFunctions._parseTokens = function(lnum, tokens, states, recDepth) {
treeHead.depth = recDepth;
treeHead.lnum = lnum;
// TODO ability to parse arbitrary parentheses
// test string: print((minus(plus(3,2),times(8,7))))
// ^ ^ these extra parens break your parser
// IF statement
if ("IF" == tokens[0].toUpperCase()) {
throw "TODO";
@@ -173,32 +177,57 @@ basicFunctions._parseTokens = function(lnum, tokens, states, recDepth) {
}
// is this a function?
else {
treeHead.value = headWord;
treeHead.type = "function";
// find and mark position of separators
// find and mark position of separators and parentheses
// properly deal with the nested function calls
var currentFunction = (states[0] == "paren") ? undefined : tokens[0];
var parenDepth = 0;
var parenStart = 0;
var parenEnd = -1;
var separators = [];
var sepInit = (tokens.length > 1 && "paren" == states[1]) ? 2 : 1;
var parenCount = 1;
for (k = sepInit; k < tokens.length; k++) {
if ("(" == tokens[k]) parenCount += 1;
else if (")" == tokens[k]) parenCount -= 1;
if (parenCount == 1 && states[k] == "sep") separators.push(k);
treeHead.value = currentFunction;
treeHead.type = (typeof currentFunction == "undefined") ? "null" : "function";
if (parenCount < 0) throw lang.syntaxfehler(lnum);
for (k = 0; k < tokens.length; k++) {
if (tokens[k] == "(") {
parenDepth += 1;
if (parenDepth == 1) parenStart = k;
}
else if (tokens[k] == ")") {
if (parenDepth == 1) parenEnd = k;
parenDepth -= 1;
}
if (parenDepth == 1 && states[k] == "sep") {
separators.push(k);
}
}
separators.push(tokens.length - (sepInit == 1 ? 0 : 1));
println("sep ("+sepInit+")["+separators.join(",")+"]");
if (parenDepth != 0) throw "Unmatched brackets";
// parse and populate leaves
var leaves = [];
if (sepInit < separators[0]) {
for (k = 0; k < separators.length; k++) {
var subtkn = tokens.slice((k == 0) ? sepInit : separators[k - 1] + 1, separators[k]);
var substa = states.slice((k == 0) ? sepInit : separators[k - 1] + 1, separators[k]);
// if there is no paren
if (parenStart == 0 && parenEnd == -1 && tokens.length > 1) {
var subtkn = tokens.slice(1, tokens.length);
var substa = states.slice(1, tokens.length);
leaves.push(basicFunctions._parseTokens(lnum, subtkn, substa, recDepth + 1));
}
else if (parenEnd > parenStart) {
separators = [parenStart].concat(separators, [parenEnd]);
// recursively parse comma-separated arguments
// print ( plus ( 3 , 2 ) , times ( 8 , 7 ) )
// s ^ e
// separators = [1,8,15]
// plus ( 3 , 2 ) / times ( 8 , 7 )
// s ^ e s ^ e
// separators = [1,5] ; [1,5]
// 3 / 2 / 8 / 7
for (k = 1; k < separators.length; k++) {
var subtkn = tokens.slice(separators[k - 1] + 1, separators[k]);
var substa = states.slice(separators[k - 1] + 1, separators[k]);
leaves.push(basicFunctions._parseTokens(lnum, subtkn, substa, recDepth + 1));
}