You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
595 lines
15 KiB
JavaScript
595 lines
15 KiB
JavaScript
var utils = require("../../utils"),
|
|
op = require("../opcodes");
|
|
|
|
/* Generates bytecode.
|
|
*
|
|
* Instructions
|
|
* ============
|
|
*
|
|
* Stack Manipulation
|
|
* ------------------
|
|
*
|
|
* [0] PUSH c
|
|
*
|
|
* stack.push(consts[c]);
|
|
*
|
|
* [1] PUSH_CURR_POS
|
|
*
|
|
* stack.push(currPos);
|
|
*
|
|
* [2] POP
|
|
*
|
|
* stack.pop();
|
|
*
|
|
* [3] POP_CURR_POS
|
|
*
|
|
* currPos = stack.pop();
|
|
*
|
|
* [4] POP_N n
|
|
*
|
|
* stack.pop(n);
|
|
*
|
|
* [5] NIP
|
|
*
|
|
* value = stack.pop();
|
|
* stack.pop();
|
|
* stack.push(value);
|
|
*
|
|
* [6] NIP_CURR_POS
|
|
*
|
|
* value = stack.pop();
|
|
* currPos = stack.pop();
|
|
* stack.push(value);
|
|
*
|
|
* [7] APPEND
|
|
*
|
|
* value = stack.pop();
|
|
* array = stack.pop();
|
|
* array.push(value);
|
|
* stack.push(array);
|
|
*
|
|
* [8] WRAP n
|
|
*
|
|
* stack.push(stack.pop(n));
|
|
*
|
|
* [9] TEXT
|
|
*
|
|
* stack.pop();
|
|
* stack.push(input.substring(stack.top(), currPos));
|
|
*
|
|
* Conditions and Loops
|
|
* --------------------
|
|
*
|
|
* [10] IF t, f
|
|
*
|
|
* if (stack.top()) {
|
|
* interpret(ip + 3, ip + 3 + t);
|
|
* } else {
|
|
* interpret(ip + 3 + t, ip + 3 + t + f);
|
|
* }
|
|
*
|
|
* [11] IF_ERROR t, f
|
|
*
|
|
* if (stack.top() === null) {
|
|
* interpret(ip + 3, ip + 3 + t);
|
|
* } else {
|
|
* interpret(ip + 3 + t, ip + 3 + t + f);
|
|
* }
|
|
*
|
|
* [12] IF_NOT_ERROR t, f
|
|
*
|
|
* if (stack.top() !== null) {
|
|
* interpret(ip + 3, ip + 3 + t);
|
|
* } else {
|
|
* interpret(ip + 3 + t, ip + 3 + t + f);
|
|
* }
|
|
*
|
|
* [13] WHILE_NOT_ERROR b
|
|
*
|
|
* while(stack.top() !== null) {
|
|
* interpret(ip + 2, ip + 2 + b);
|
|
* }
|
|
*
|
|
* Matching
|
|
* --------
|
|
*
|
|
* [14] MATCH_ANY a, f, ...
|
|
*
|
|
* if (input.length > currPos) {
|
|
* interpret(ip + 3, ip + 3 + a);
|
|
* } else {
|
|
* interpret(ip + 3 + a, ip + 3 + a + f);
|
|
* }
|
|
*
|
|
* [15] MATCH_STRING s, a, f, ...
|
|
*
|
|
* if (input.substr(currPos, consts[s].length) === consts[s]) {
|
|
* interpret(ip + 4, ip + 4 + a);
|
|
* } else {
|
|
* interpret(ip + 4 + a, ip + 4 + a + f);
|
|
* }
|
|
*
|
|
* [16] MATCH_STRING_IC s, a, f, ...
|
|
*
|
|
* if (input.substr(currPos, consts[s].length).toLowerCase() === consts[s]) {
|
|
* interpret(ip + 4, ip + 4 + a);
|
|
* } else {
|
|
* interpret(ip + 4 + a, ip + 4 + a + f);
|
|
* }
|
|
*
|
|
* [17] MATCH_REGEXP r, a, f, ...
|
|
*
|
|
* if (consts[r].test(input.charAt(currPos))) {
|
|
* interpret(ip + 4, ip + 4 + a);
|
|
* } else {
|
|
* interpret(ip + 4 + a, ip + 4 + a + f);
|
|
* }
|
|
*
|
|
* [18] ACCEPT_N n
|
|
*
|
|
* stack.push(input.substring(currPos, n));
|
|
* currPos += n;
|
|
*
|
|
* [19] ACCEPT_STRING s
|
|
*
|
|
* stack.push(consts[s]);
|
|
* currPos += consts[s].length;
|
|
*
|
|
* [20] FAIL e
|
|
*
|
|
* stack.push(null);
|
|
* fail(consts[e]);
|
|
*
|
|
* Calls
|
|
* -----
|
|
*
|
|
* [21] REPORT_SAVED_POS p
|
|
*
|
|
* reportedPos = stack[p];
|
|
*
|
|
* [22] REPORT_CURR_POS
|
|
*
|
|
* reportedPos = currPos;
|
|
*
|
|
* [23] CALL f, n, pc, p1, p2, ..., pN
|
|
*
|
|
* value = consts[f](stack[p1], ..., stack[pN]);
|
|
* stack.pop(n);
|
|
* stack.push(value);
|
|
*
|
|
* Rules
|
|
* -----
|
|
*
|
|
* [24] RULE r
|
|
*
|
|
* stack.push(parseRule(r));
|
|
*
|
|
* Failure Reporting
|
|
* -----------------
|
|
*
|
|
* [25] SILENT_FAILS_ON
|
|
*
|
|
* silentFails++;
|
|
*
|
|
* [26] SILENT_FAILS_OFF
|
|
*
|
|
* silentFails--;
|
|
*/
|
|
module.exports = function(ast, options) {
|
|
var consts = [];
|
|
|
|
function addConst(value) {
|
|
var index = utils.indexOf(consts, function(c) { return c === value; });
|
|
|
|
return index === -1 ? consts.push(value) - 1 : index;
|
|
}
|
|
|
|
function addFunctionConst(params, code) {
|
|
return addConst(
|
|
"function(" + params.join(", ") + ") {" + code + "}"
|
|
);
|
|
}
|
|
|
|
function buildSequence() {
|
|
return Array.prototype.concat.apply([], arguments);
|
|
}
|
|
|
|
function buildCondition(condCode, thenCode, elseCode) {
|
|
return condCode.concat(
|
|
[thenCode.length, elseCode.length],
|
|
thenCode,
|
|
elseCode
|
|
);
|
|
}
|
|
|
|
function buildLoop(condCode, bodyCode) {
|
|
return condCode.concat([bodyCode.length], bodyCode);
|
|
}
|
|
|
|
function buildCall(functionIndex, delta, env, sp) {
|
|
var params = utils.map( utils.values(env), function(p) { return sp - p; });
|
|
|
|
return [op.CALL, functionIndex, delta, params.length].concat(params);
|
|
}
|
|
|
|
function buildSimplePredicate(expression, negative, context) {
|
|
var emptyStringIndex = addConst('""'),
|
|
nullIndex = addConst('null');
|
|
|
|
return buildSequence(
|
|
[op.PUSH_CURR_POS],
|
|
[op.SILENT_FAILS_ON],
|
|
generate(expression, {
|
|
sp: context.sp + 1,
|
|
env: { },
|
|
action: null
|
|
}),
|
|
[op.SILENT_FAILS_OFF],
|
|
buildCondition(
|
|
[negative ? op.IF_ERROR : op.IF_NOT_ERROR],
|
|
buildSequence(
|
|
[op.POP],
|
|
[negative ? op.POP : op.POP_CURR_POS],
|
|
[op.PUSH, emptyStringIndex]
|
|
),
|
|
buildSequence(
|
|
[op.POP],
|
|
[negative ? op.POP_CURR_POS : op.POP],
|
|
[op.PUSH, nullIndex]
|
|
)
|
|
)
|
|
);
|
|
}
|
|
|
|
function buildSemanticPredicate(code, negative, context) {
|
|
var functionIndex = addFunctionConst(utils.keys(context.env), code),
|
|
emptyStringIndex = addConst('""'),
|
|
nullIndex = addConst('null');
|
|
|
|
return buildSequence(
|
|
[op.REPORT_CURR_POS],
|
|
buildCall(functionIndex, 0, context.env, context.sp),
|
|
buildCondition(
|
|
[op.IF],
|
|
buildSequence(
|
|
[op.POP],
|
|
[op.PUSH, negative ? nullIndex : emptyStringIndex]
|
|
),
|
|
buildSequence(
|
|
[op.POP],
|
|
[op.PUSH, negative ? emptyStringIndex : nullIndex]
|
|
)
|
|
)
|
|
);
|
|
}
|
|
|
|
function buildAppendLoop(expressionCode) {
|
|
return buildLoop(
|
|
[op.WHILE_NOT_ERROR],
|
|
buildSequence([op.APPEND], expressionCode)
|
|
);
|
|
}
|
|
|
|
var generate = utils.buildNodeVisitor({
|
|
grammar: function(node) {
|
|
utils.each(node.rules, generate);
|
|
|
|
node.consts = consts;
|
|
},
|
|
|
|
rule: function(node) {
|
|
node.bytecode = generate(node.expression, {
|
|
sp: -1, // stack pointer
|
|
env: { }, // mapping of label names to stack positions
|
|
action: null // action nodes pass themselves to children here
|
|
});
|
|
},
|
|
|
|
named: function(node, context) {
|
|
var nameIndex = addConst(utils.quote(node.name));
|
|
|
|
/*
|
|
* The code generated below is slightly suboptimal because |FAIL| pushes
|
|
* to the stack, so we need to stick a |POP| in front of it. We lack a
|
|
* dedicated instruction that would just report the failure and not touch
|
|
* the stack.
|
|
*/
|
|
return buildSequence(
|
|
[op.SILENT_FAILS_ON],
|
|
generate(node.expression, context),
|
|
[op.SILENT_FAILS_OFF],
|
|
buildCondition([op.IF_ERROR], [op.FAIL, nameIndex], [])
|
|
);
|
|
},
|
|
|
|
choice: function(node, context) {
|
|
function buildAlternativesCode(alternatives, context) {
|
|
return buildSequence(
|
|
generate(alternatives[0], {
|
|
sp: context.sp,
|
|
env: { },
|
|
action: null
|
|
}),
|
|
alternatives.length > 1
|
|
? buildCondition(
|
|
[op.IF_ERROR],
|
|
buildSequence(
|
|
[op.POP],
|
|
buildAlternativesCode(alternatives.slice(1), context)
|
|
),
|
|
[]
|
|
)
|
|
: []
|
|
);
|
|
}
|
|
|
|
return buildAlternativesCode(node.alternatives, context);
|
|
},
|
|
|
|
action: function(node, context) {
|
|
var env = { },
|
|
emitCall = node.expression.type !== "sequence"
|
|
|| node.expression.elements.length === 0;
|
|
expressionCode = generate(node.expression, {
|
|
sp: context.sp + (emitCall ? 1 : 0),
|
|
env: env,
|
|
action: node
|
|
}),
|
|
functionIndex = addFunctionConst(utils.keys(env), node.code);
|
|
|
|
return emitCall
|
|
? buildSequence(
|
|
[op.PUSH_CURR_POS],
|
|
expressionCode,
|
|
buildCondition(
|
|
[op.IF_NOT_ERROR],
|
|
buildSequence(
|
|
[op.REPORT_SAVED_POS, 1],
|
|
buildCall(functionIndex, 1, env, context.sp + 2)
|
|
),
|
|
[]
|
|
),
|
|
buildCondition([op.IF_ERROR], [op.NIP_CURR_POS], [op.NIP])
|
|
)
|
|
: expressionCode;
|
|
},
|
|
|
|
sequence: function(node, context) {
|
|
var emptyArrayIndex, nullIndex;
|
|
|
|
function buildElementsCode(elements, context) {
|
|
var processedCount, functionIndex;
|
|
|
|
if (elements.length > 0) {
|
|
processedCount = node.elements.length - elements.slice(1).length;
|
|
|
|
return buildSequence(
|
|
generate(elements[0], context),
|
|
buildCondition(
|
|
[op.IF_NOT_ERROR],
|
|
buildElementsCode(elements.slice(1), {
|
|
sp: context.sp + 1,
|
|
env: context.env,
|
|
action: context.action
|
|
}),
|
|
buildSequence(
|
|
processedCount > 1 ? [op.POP_N, processedCount] : [op.POP],
|
|
[op.POP_CURR_POS],
|
|
[op.PUSH, nullIndex]
|
|
)
|
|
)
|
|
);
|
|
} else {
|
|
if (context.action) {
|
|
functionIndex = addFunctionConst(
|
|
utils.keys(context.env),
|
|
context.action.code
|
|
);
|
|
|
|
return buildSequence(
|
|
[op.REPORT_SAVED_POS, node.elements.length],
|
|
buildCall(
|
|
functionIndex,
|
|
node.elements.length,
|
|
context.env,
|
|
context.sp
|
|
),
|
|
buildCondition([op.IF_ERROR], [op.NIP_CURR_POS], [op.NIP])
|
|
);
|
|
} else {
|
|
return buildSequence([op.WRAP, node.elements.length], [op.NIP]);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (node.elements.length > 0) {
|
|
nullIndex = addConst('null');
|
|
|
|
return buildSequence(
|
|
[op.PUSH_CURR_POS],
|
|
buildElementsCode(node.elements, {
|
|
sp: context.sp + 1,
|
|
env: context.env,
|
|
action: context.action
|
|
})
|
|
);
|
|
} else {
|
|
emptyArrayIndex = addConst('[]');
|
|
|
|
return [op.PUSH, emptyArrayIndex];
|
|
}
|
|
},
|
|
|
|
labeled: function(node, context) {
|
|
context.env[node.label] = context.sp + 1;
|
|
|
|
return generate(node.expression, {
|
|
sp: context.sp,
|
|
env: { },
|
|
action: null
|
|
});
|
|
},
|
|
|
|
text: function(node, context) {
|
|
return buildSequence(
|
|
[op.PUSH_CURR_POS],
|
|
generate(node.expression, {
|
|
sp: context.sp + 1,
|
|
env: { },
|
|
action: null
|
|
}),
|
|
buildCondition([op.IF_NOT_ERROR], [op.TEXT], []),
|
|
[op.NIP]
|
|
);
|
|
},
|
|
|
|
simple_and: function(node, context) {
|
|
return buildSimplePredicate(node.expression, false, context);
|
|
},
|
|
|
|
simple_not: function(node, context) {
|
|
return buildSimplePredicate(node.expression, true, context);
|
|
},
|
|
|
|
semantic_and: function(node, context) {
|
|
return buildSemanticPredicate(node.code, false, context);
|
|
},
|
|
|
|
semantic_not: function(node, context) {
|
|
return buildSemanticPredicate(node.code, true, context);
|
|
},
|
|
|
|
optional: function(node, context) {
|
|
var emptyStringIndex = addConst('""');
|
|
|
|
return buildSequence(
|
|
generate(node.expression, {
|
|
sp: context.sp,
|
|
env: { },
|
|
action: null
|
|
}),
|
|
buildCondition(
|
|
[op.IF_ERROR],
|
|
buildSequence([op.POP], [op.PUSH, emptyStringIndex]),
|
|
[]
|
|
)
|
|
);
|
|
},
|
|
|
|
zero_or_more: function(node, context) {
|
|
var emptyArrayIndex = addConst('[]');
|
|
expressionCode = generate(node.expression, {
|
|
sp: context.sp + 1,
|
|
env: { },
|
|
action: null
|
|
});
|
|
|
|
return buildSequence(
|
|
[op.PUSH, emptyArrayIndex],
|
|
expressionCode,
|
|
buildAppendLoop(expressionCode),
|
|
[op.POP]
|
|
);
|
|
},
|
|
|
|
one_or_more: function(node, context) {
|
|
var emptyArrayIndex = addConst('[]');
|
|
nullIndex = addConst('null');
|
|
expressionCode = generate(node.expression, {
|
|
sp: context.sp + 1,
|
|
env: { },
|
|
action: null
|
|
});
|
|
|
|
return buildSequence(
|
|
[op.PUSH, emptyArrayIndex],
|
|
expressionCode,
|
|
buildCondition(
|
|
[op.IF_NOT_ERROR],
|
|
buildSequence(buildAppendLoop(expressionCode), [op.POP]),
|
|
buildSequence([op.POP], [op.POP], [op.PUSH, nullIndex])
|
|
)
|
|
);
|
|
},
|
|
|
|
rule_ref: function(node) {
|
|
return [op.RULE, utils.indexOfRuleByName(ast, node.name)];
|
|
},
|
|
|
|
literal: function(node) {
|
|
var stringIndex, expectedIndex;
|
|
|
|
if (node.value.length > 0) {
|
|
stringIndex = addConst(node.ignoreCase
|
|
? utils.quote(node.value.toLowerCase())
|
|
: utils.quote(node.value)
|
|
);
|
|
expectedIndex = addConst(utils.quote(utils.quote(node.value)));
|
|
|
|
/*
|
|
* For case-sensitive strings the value must match the beginning of the
|
|
* remaining input exactly. As a result, we can use |ACCEPT_STRING| and
|
|
* save one |substr| call that would be needed if we used |ACCEPT_N|.
|
|
*/
|
|
return buildCondition(
|
|
node.ignoreCase
|
|
? [op.MATCH_STRING_IC, stringIndex]
|
|
: [op.MATCH_STRING, stringIndex],
|
|
node.ignoreCase
|
|
? [op.ACCEPT_N, node.value.length]
|
|
: [op.ACCEPT_STRING, stringIndex],
|
|
[op.FAIL, expectedIndex]
|
|
);
|
|
} else {
|
|
stringIndex = addConst('""');
|
|
|
|
return [op.PUSH, stringIndex];
|
|
}
|
|
},
|
|
|
|
"class": function(node) {
|
|
var regexp, regexpIndex, expectedIndex;
|
|
|
|
if (node.parts.length > 0) {
|
|
regexp = '/^['
|
|
+ (node.inverted ? '^' : '')
|
|
+ utils.map(node.parts, function(part) {
|
|
return part instanceof Array
|
|
? utils.quoteForRegexpClass(part[0])
|
|
+ '-'
|
|
+ utils.quoteForRegexpClass(part[1])
|
|
: utils.quoteForRegexpClass(part);
|
|
}).join('')
|
|
+ ']/' + (node.ignoreCase ? 'i' : '');
|
|
} else {
|
|
/*
|
|
* IE considers regexps /[]/ and /[^]/ as syntactically invalid, so we
|
|
* translate them into euqivalents it can handle.
|
|
*/
|
|
regexp = node.inverted ? '/^[\\S\\s]/' : '/^(?!)/';
|
|
}
|
|
|
|
regexpIndex = addConst(regexp);
|
|
expectedIndex = addConst(utils.quote(node.rawText));
|
|
|
|
return buildCondition(
|
|
[op.MATCH_REGEXP, regexpIndex],
|
|
[op.ACCEPT_N, 1],
|
|
[op.FAIL, expectedIndex]
|
|
);
|
|
},
|
|
|
|
any: function(node) {
|
|
var expectedIndex = addConst(utils.quote("any character"));
|
|
|
|
return buildCondition(
|
|
[op.MATCH_ANY],
|
|
[op.ACCEPT_N, 1],
|
|
[op.FAIL, expectedIndex]
|
|
);
|
|
}
|
|
});
|
|
|
|
generate(ast);
|
|
};
|