From 62593b0ab8dfaa63a788702762146803c9845a98 Mon Sep 17 00:00:00 2001
From: Tangent Wantwight <tangent128@gmail.com>
Date: Fri, 17 May 2024 20:26:54 -0400
Subject: [PATCH 01/12] Start stubbing out Pratt parser - parse integers
---
src/lib/expr.test.ts | 23 +++++++++++
src/lib/expr.ts | 94 ++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 113 insertions(+), 4 deletions(-)
create mode 100644 src/lib/expr.test.ts
diff --git a/src/lib/expr.test.ts b/src/lib/expr.test.ts
new file mode 100644
index 0000000..eea76f7
--- /dev/null
+++ b/src/lib/expr.test.ts
@@ -0,0 +1,23 @@
+import { AsText, TextPiece } from "../words";
+import { Expr } from "./expr";
+
+describe("expr", () => {
+ test.each([
+ ["1", "1"],
+ // ["1 + 2", "3"],
+ // ["1 - 2", "-1"],
+ // ["1 * 2", "2"],
+ // ["1 / 2", "0.5"],
+ // ["1 // 2", "0"],
+ // TODO: operator precedence
+ // TODO: parentheses
+ // TODO; eror reporting
+ ])("Expr does math: %s", (expression, result) => {
+ const actualResult = Expr({}, [{ text: expression }]);
+ console.log(actualResult)
+ expect("error" in actualResult).toBeFalsy();
+ expect(AsText(actualResult as TextPiece)).toEqual(result);
+ });
+
+ // TODO: handle expr prefix
+});
diff --git a/src/lib/expr.ts b/src/lib/expr.ts
index 59e01f3..27cc2fe 100644
--- a/src/lib/expr.ts
+++ b/src/lib/expr.ts
@@ -1,4 +1,4 @@
-import { AsText, ProcResult, TextPiece } from "../words";
+import { AsText, ErrorResult, ProcResult, TextPiece } from "../words";
export function Expr({}, argv: TextPiece[]): ProcResult {
const name = argv[0];
@@ -6,7 +6,93 @@ export function Expr({}, argv: TextPiece[]): ProcResult {
// being called as [expr ...], not fallback for math
argv.splice(0, 1);
}
- return {
- text: `Will do math to solve ${argv.map(AsText).join(" ")} eventually`,
- };
+
+ const expression = argv.map(AsText).join(" ").trim();
+
+ const parser = new ExpressionParser(expression);
+ const result = parser.parsePrefixOp();
+
+ if ("value" in result) {
+ return { text: String(result.value) };
+ } else {
+ return result;
+ }
}
+
+// ---------------------------
+
+// Pratt parser for evaluating arithmatic expressions
+
+const PLUS_TOKEN = /\s*(\+)/y;
+const MINUS_TOKEN = /\s*(\-)/y;
+const TIMES_TOKEN = /\s*(\*)/y;
+const FLOOR_TOKEN = /\s*(\/\/)/y;
+const DIV_TOKEN = /\s*(\/)/y;
+
+const NUMBER_TOKEN = /\s*(\d+)/y;
+
+type Value = { value: number };
+
+type TokenHandler = {
+ leftBindingPower: number;
+ token: RegExp;
+ parse: (matched: string, parser: ExpressionParser) => Value | ErrorResult;
+};
+
+const Operators: TokenHandler[] = [
+ {
+ leftBindingPower: -1,
+ token: NUMBER_TOKEN,
+ parse: (matched) => ({ value: Number(matched) }),
+ },
+];
+
+class ExpressionParser {
+ pos: number = 0;
+
+ constructor(public text: string) {}
+
+ next(token: RegExp): string | null {
+ token.lastIndex = this.pos;
+ const matches = token.exec(this.text);
+ if (matches) {
+ this.pos = token.lastIndex;
+ return matches[1];
+ } else {
+ return null;
+ }
+ }
+
+ /** Tries to match one of the given tokens & returns the value of the handler. If none match, returns null. */
+ tryAll(options: TokenHandler[]): Value | ErrorResult | null {
+ for (const option of options) {
+ const match = this.next(option.token);
+ if (match) {
+ return option.parse(match, this);
+ }
+ }
+ return null;
+ }
+
+ parsePrefixOp(): Value | ErrorResult {
+ return (
+ this.tryAll(
+ Operators.filter((operator) => operator.leftBindingPower == -1)
+ ) ?? { error: "Couldn't parse number" }
+ );
+ }
+}
+
+// parse expression:
+// must parse sub-expression with right binding power 0
+// must be at EOF
+
+// parse sub-expression with right binding power :
+// must parse a prefix op
+// parse as many postfix ops w/ left binding power > right binding power
+
+// parse op:
+// must parse associated token (if success- failing the rest of the op fails *everything*)
+// depending on op:
+// maybe parse sub-expressions with op's right-binding power
+// maybe consume other tokens
From bf44d84e175b6f03ef0760945def3967f3517fa0 Mon Sep 17 00:00:00 2001
From: Tangent Wantwight <tangent128@gmail.com>
Date: Fri, 17 May 2024 20:50:54 -0400
Subject: [PATCH 02/12] impl +
---
src/lib/expr.test.ts | 2 +-
src/lib/expr.ts | 57 ++++++++++++++++++++++++++++++++++++++++----
2 files changed, 53 insertions(+), 6 deletions(-)
diff --git a/src/lib/expr.test.ts b/src/lib/expr.test.ts
index eea76f7..3b7b4ce 100644
--- a/src/lib/expr.test.ts
+++ b/src/lib/expr.test.ts
@@ -4,7 +4,7 @@ import { Expr } from "./expr";
describe("expr", () => {
test.each([
["1", "1"],
- // ["1 + 2", "3"],
+ ["1 + 2", "3"],
// ["1 - 2", "-1"],
// ["1 * 2", "2"],
// ["1 / 2", "0.5"],
diff --git a/src/lib/expr.ts b/src/lib/expr.ts
index 27cc2fe..9926251 100644
--- a/src/lib/expr.ts
+++ b/src/lib/expr.ts
@@ -10,7 +10,7 @@ export function Expr({}, argv: TextPiece[]): ProcResult {
const expression = argv.map(AsText).join(" ").trim();
const parser = new ExpressionParser(expression);
- const result = parser.parsePrefixOp();
+ const result = parser.parseSubExpression(0);
if ("value" in result) {
return { text: String(result.value) };
@@ -36,17 +36,40 @@ type Value = { value: number };
type TokenHandler = {
leftBindingPower: number;
token: RegExp;
- parse: (matched: string, parser: ExpressionParser) => Value | ErrorResult;
+ parse: (
+ left: Value,
+ matched: string,
+ parser: ExpressionParser
+ ) => Value | ErrorResult;
};
+function map(
+ value: Value | ErrorResult,
+ op: (value: number) => Value | ErrorResult
+): Value | ErrorResult {
+ if ("error" in value) {
+ return value;
+ } else {
+ return op(value.value);
+ }
+}
+
const Operators: TokenHandler[] = [
{
leftBindingPower: -1,
token: NUMBER_TOKEN,
- parse: (matched) => ({ value: Number(matched) }),
+ parse: (left, matched) => ({ value: Number(matched) }),
+ },
+ {
+ leftBindingPower: 10,
+ token: PLUS_TOKEN,
+ parse: ({ value: left }, matched, parser) =>
+ map(parser.parseSubExpression(11), (right) => ({ value: left + right })),
},
];
+const ZERO = { value: 0 };
+
class ExpressionParser {
pos: number = 0;
@@ -64,11 +87,11 @@ class ExpressionParser {
}
/** Tries to match one of the given tokens & returns the value of the handler. If none match, returns null. */
- tryAll(options: TokenHandler[]): Value | ErrorResult | null {
+ tryAll(left: Value, options: TokenHandler[]): Value | ErrorResult | null {
for (const option of options) {
const match = this.next(option.token);
if (match) {
- return option.parse(match, this);
+ return option.parse(left, match, this);
}
}
return null;
@@ -77,10 +100,34 @@ class ExpressionParser {
parsePrefixOp(): Value | ErrorResult {
return (
this.tryAll(
+ ZERO,
Operators.filter((operator) => operator.leftBindingPower == -1)
) ?? { error: "Couldn't parse number" }
);
}
+
+ parseSubExpression(rightBindingPower: number): Value | ErrorResult {
+ let value = this.parsePrefixOp();
+ if ("error" in value) {
+ return value;
+ }
+
+ do {
+ const newValue = this.tryAll(
+ value,
+ Operators.filter(
+ (operator) => operator.leftBindingPower > rightBindingPower
+ )
+ );
+
+ if (newValue == null) {
+ break;
+ }
+ value = newValue;
+ } while (!("error" in value));
+
+ return value;
+ }
}
// parse expression:
From 1a46130b1d0959d2ec85fa22c151d1d96a59ca8d Mon Sep 17 00:00:00 2001
From: Tangent Wantwight <tangent128@gmail.com>
Date: Fri, 17 May 2024 20:52:33 -0400
Subject: [PATCH 03/12] impl - * // /
---
src/lib/expr.test.ts | 8 ++++----
src/lib/expr.ts | 26 ++++++++++++++++++++++++++
2 files changed, 30 insertions(+), 4 deletions(-)
diff --git a/src/lib/expr.test.ts b/src/lib/expr.test.ts
index 3b7b4ce..31b4714 100644
--- a/src/lib/expr.test.ts
+++ b/src/lib/expr.test.ts
@@ -5,10 +5,10 @@ describe("expr", () => {
test.each([
["1", "1"],
["1 + 2", "3"],
- // ["1 - 2", "-1"],
- // ["1 * 2", "2"],
- // ["1 / 2", "0.5"],
- // ["1 // 2", "0"],
+ ["1 - 2", "-1"],
+ ["1 * 2", "2"],
+ ["1 / 2", "0.5"],
+ ["1 // 2", "0"],
// TODO: operator precedence
// TODO: parentheses
// TODO; eror reporting
diff --git a/src/lib/expr.ts b/src/lib/expr.ts
index 9926251..880ee2a 100644
--- a/src/lib/expr.ts
+++ b/src/lib/expr.ts
@@ -66,6 +66,32 @@ const Operators: TokenHandler[] = [
parse: ({ value: left }, matched, parser) =>
map(parser.parseSubExpression(11), (right) => ({ value: left + right })),
},
+ {
+ leftBindingPower: 10,
+ token: MINUS_TOKEN,
+ parse: ({ value: left }, matched, parser) =>
+ map(parser.parseSubExpression(11), (right) => ({ value: left - right })),
+ },
+ {
+ leftBindingPower: 20,
+ token: TIMES_TOKEN,
+ parse: ({ value: left }, matched, parser) =>
+ map(parser.parseSubExpression(11), (right) => ({ value: left * right })),
+ },
+ {
+ leftBindingPower: 20,
+ token: FLOOR_TOKEN,
+ parse: ({ value: left }, matched, parser) =>
+ map(parser.parseSubExpression(11), (right) => ({
+ value: Math.floor(left / right),
+ })),
+ },
+ {
+ leftBindingPower: 20,
+ token: DIV_TOKEN,
+ parse: ({ value: left }, matched, parser) =>
+ map(parser.parseSubExpression(11), (right) => ({ value: left / right })),
+ },
];
const ZERO = { value: 0 };
From 21e8d95f98615bf16af178ce02cece59c1a2306a Mon Sep 17 00:00:00 2001
From: Tangent Wantwight <tangent128@gmail.com>
Date: Sat, 18 May 2024 21:24:19 -0400
Subject: [PATCH 04/12] Fix expression parser to require parsing full string
---
src/lib/expr.test.ts | 38 +++++++++++++++++++++++---------------
src/lib/expr.ts | 4 ++++
2 files changed, 27 insertions(+), 15 deletions(-)
diff --git a/src/lib/expr.test.ts b/src/lib/expr.test.ts
index 31b4714..a4917c9 100644
--- a/src/lib/expr.test.ts
+++ b/src/lib/expr.test.ts
@@ -2,21 +2,29 @@ import { AsText, TextPiece } from "../words";
import { Expr } from "./expr";
describe("expr", () => {
- test.each([
- ["1", "1"],
- ["1 + 2", "3"],
- ["1 - 2", "-1"],
- ["1 * 2", "2"],
- ["1 / 2", "0.5"],
- ["1 // 2", "0"],
- // TODO: operator precedence
- // TODO: parentheses
- // TODO; eror reporting
- ])("Expr does math: %s", (expression, result) => {
- const actualResult = Expr({}, [{ text: expression }]);
- console.log(actualResult)
- expect("error" in actualResult).toBeFalsy();
- expect(AsText(actualResult as TextPiece)).toEqual(result);
+ describe("Expr does math", () => {
+ test.each([
+ ["1", "1"],
+ ["1 + 2", "3"],
+ ["1 - 2", "-1"],
+ ["1 * 2", "2"],
+ ["1 / 2", "0.5"],
+ ["1 // 2", "0"],
+ // TODO: operator precedence
+ // TODO: parentheses
+ ])("%s", (expression, result) => {
+ const actualResult = Expr({}, [{ text: expression }]);
+ expect("error" in actualResult).toBeFalsy();
+ expect(AsText(actualResult as TextPiece)).toEqual(result);
+ });
+ });
+
+ // TODO; error reporting
+ describe("Expr rejects invalid expressions", () => {
+ test.each([["1 $ 2"], ["1 1 + 2"], ["$ 1"]])("%s", (expression) => {
+ const actualResult = Expr({}, [{ text: expression }]);
+ expect("error" in actualResult).toBeTruthy();
+ });
});
// TODO: handle expr prefix
diff --git a/src/lib/expr.ts b/src/lib/expr.ts
index 880ee2a..f4a72de 100644
--- a/src/lib/expr.ts
+++ b/src/lib/expr.ts
@@ -12,6 +12,10 @@ export function Expr({}, argv: TextPiece[]): ProcResult {
const parser = new ExpressionParser(expression);
const result = parser.parseSubExpression(0);
+ if(parser.pos != expression.length) {
+ return {error: "Couldn't parse full expression"}
+ }
+
if ("value" in result) {
return { text: String(result.value) };
} else {
From 1078dc365339c917462e6cd50801a59ad0aa6408 Mon Sep 17 00:00:00 2001
From: Tangent Wantwight <tangent128@gmail.com>
Date: Sat, 18 May 2024 21:24:43 -0400
Subject: [PATCH 05/12] Fix binding power of * // /
---
src/lib/expr.ts | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/src/lib/expr.ts b/src/lib/expr.ts
index f4a72de..c0d1e96 100644
--- a/src/lib/expr.ts
+++ b/src/lib/expr.ts
@@ -80,13 +80,13 @@ const Operators: TokenHandler[] = [
leftBindingPower: 20,
token: TIMES_TOKEN,
parse: ({ value: left }, matched, parser) =>
- map(parser.parseSubExpression(11), (right) => ({ value: left * right })),
+ map(parser.parseSubExpression(21), (right) => ({ value: left * right })),
},
{
leftBindingPower: 20,
token: FLOOR_TOKEN,
parse: ({ value: left }, matched, parser) =>
- map(parser.parseSubExpression(11), (right) => ({
+ map(parser.parseSubExpression(21), (right) => ({
value: Math.floor(left / right),
})),
},
@@ -94,7 +94,7 @@ const Operators: TokenHandler[] = [
leftBindingPower: 20,
token: DIV_TOKEN,
parse: ({ value: left }, matched, parser) =>
- map(parser.parseSubExpression(11), (right) => ({ value: left / right })),
+ map(parser.parseSubExpression(21), (right) => ({ value: left / right })),
},
];
From 5a34b0f6f7b5a0b6a9a77a8166cb3a3752499b0d Mon Sep 17 00:00:00 2001
From: Tangent Wantwight <tangent128@gmail.com>
Date: Sat, 18 May 2024 21:33:17 -0400
Subject: [PATCH 06/12] Factor out common infix op logic
---
src/lib/expr.ts | 46 ++++++++++++++--------------------------------
1 file changed, 14 insertions(+), 32 deletions(-)
diff --git a/src/lib/expr.ts b/src/lib/expr.ts
index c0d1e96..4af04a1 100644
--- a/src/lib/expr.ts
+++ b/src/lib/expr.ts
@@ -58,44 +58,26 @@ function map(
}
}
+function makeInfixOp(token:RegExp, leftBindingPower: number,rightBindingPower: number, op: (left: number, right: number) => Value | ErrorResult):TokenHandler {
+ return {
+ leftBindingPower,
+ token,
+ parse: ({ value: left }, matched, parser) =>
+ map(parser.parseSubExpression(rightBindingPower), (right) => op(left, right)),
+ }
+}
+
const Operators: TokenHandler[] = [
{
leftBindingPower: -1,
token: NUMBER_TOKEN,
parse: (left, matched) => ({ value: Number(matched) }),
},
- {
- leftBindingPower: 10,
- token: PLUS_TOKEN,
- parse: ({ value: left }, matched, parser) =>
- map(parser.parseSubExpression(11), (right) => ({ value: left + right })),
- },
- {
- leftBindingPower: 10,
- token: MINUS_TOKEN,
- parse: ({ value: left }, matched, parser) =>
- map(parser.parseSubExpression(11), (right) => ({ value: left - right })),
- },
- {
- leftBindingPower: 20,
- token: TIMES_TOKEN,
- parse: ({ value: left }, matched, parser) =>
- map(parser.parseSubExpression(21), (right) => ({ value: left * right })),
- },
- {
- leftBindingPower: 20,
- token: FLOOR_TOKEN,
- parse: ({ value: left }, matched, parser) =>
- map(parser.parseSubExpression(21), (right) => ({
- value: Math.floor(left / right),
- })),
- },
- {
- leftBindingPower: 20,
- token: DIV_TOKEN,
- parse: ({ value: left }, matched, parser) =>
- map(parser.parseSubExpression(21), (right) => ({ value: left / right })),
- },
+ makeInfixOp(PLUS_TOKEN, 10, 11, (left, right) => ({ value: left + right })),
+ makeInfixOp(MINUS_TOKEN, 10, 11, (left, right) => ({ value: left - right })),
+ makeInfixOp(TIMES_TOKEN, 10, 11, (left, right) => ({ value: left * right })),
+ makeInfixOp(FLOOR_TOKEN, 10, 11, (left, right) => ({ value: Math.floor(left / right) })),
+ makeInfixOp(DIV_TOKEN, 10, 11, (left, right) => ({ value: left / right })),
];
const ZERO = { value: 0 };
From 2770a2de3bdbfa67b66cdd7eff95590bcfa1092f Mon Sep 17 00:00:00 2001
From: Tangent Wantwight <tangent128@gmail.com>
Date: Sat, 18 May 2024 21:53:23 -0400
Subject: [PATCH 07/12] impl unary minus
---
src/lib/expr.test.ts | 1 +
src/lib/expr.ts | 6 ++++++
2 files changed, 7 insertions(+)
diff --git a/src/lib/expr.test.ts b/src/lib/expr.test.ts
index a4917c9..e998605 100644
--- a/src/lib/expr.test.ts
+++ b/src/lib/expr.test.ts
@@ -5,6 +5,7 @@ describe("expr", () => {
describe("Expr does math", () => {
test.each([
["1", "1"],
+ ["-1", "-1"],
["1 + 2", "3"],
["1 - 2", "-1"],
["1 * 2", "2"],
diff --git a/src/lib/expr.ts b/src/lib/expr.ts
index 4af04a1..4bd6b09 100644
--- a/src/lib/expr.ts
+++ b/src/lib/expr.ts
@@ -73,6 +73,12 @@ const Operators: TokenHandler[] = [
token: NUMBER_TOKEN,
parse: (left, matched) => ({ value: Number(matched) }),
},
+ {
+ leftBindingPower: -1,
+ token: MINUS_TOKEN,
+ parse: (left, matched, parser) =>
+ map(parser.parseSubExpression(0), (right) => ({value: -right})),
+ },
makeInfixOp(PLUS_TOKEN, 10, 11, (left, right) => ({ value: left + right })),
makeInfixOp(MINUS_TOKEN, 10, 11, (left, right) => ({ value: left - right })),
makeInfixOp(TIMES_TOKEN, 10, 11, (left, right) => ({ value: left * right })),
From 2b6aff0dab0ed7fed5410dead2ed4bf15e6b1270 Mon Sep 17 00:00:00 2001
From: Tangent Wantwight <tangent128@gmail.com>
Date: Sat, 18 May 2024 23:15:46 -0400
Subject: [PATCH 08/12] Fix some binding powers
---
src/lib/expr.ts | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/src/lib/expr.ts b/src/lib/expr.ts
index 4bd6b09..00dce77 100644
--- a/src/lib/expr.ts
+++ b/src/lib/expr.ts
@@ -77,13 +77,13 @@ const Operators: TokenHandler[] = [
leftBindingPower: -1,
token: MINUS_TOKEN,
parse: (left, matched, parser) =>
- map(parser.parseSubExpression(0), (right) => ({value: -right})),
+ map(parser.parseSubExpression(99), (right) => ({value: -right})),
},
makeInfixOp(PLUS_TOKEN, 10, 11, (left, right) => ({ value: left + right })),
makeInfixOp(MINUS_TOKEN, 10, 11, (left, right) => ({ value: left - right })),
- makeInfixOp(TIMES_TOKEN, 10, 11, (left, right) => ({ value: left * right })),
- makeInfixOp(FLOOR_TOKEN, 10, 11, (left, right) => ({ value: Math.floor(left / right) })),
- makeInfixOp(DIV_TOKEN, 10, 11, (left, right) => ({ value: left / right })),
+ makeInfixOp(TIMES_TOKEN, 20, 21, (left, right) => ({ value: left * right })),
+ makeInfixOp(FLOOR_TOKEN, 20, 21, (left, right) => ({ value: Math.floor(left / right) })),
+ makeInfixOp(DIV_TOKEN, 20, 21, (left, right) => ({ value: left / right })),
];
const ZERO = { value: 0 };
From ce991fd12a0bec89f2c7c3857bd50f5d124b454d Mon Sep 17 00:00:00 2001
From: Tangent Wantwight <tangent128@gmail.com>
Date: Sat, 18 May 2024 23:22:50 -0400
Subject: [PATCH 09/12] impl modulo (handle negative divisors how people
expect)
---
src/lib/expr.test.ts | 5 +++++
src/lib/expr.ts | 2 ++
2 files changed, 7 insertions(+)
diff --git a/src/lib/expr.test.ts b/src/lib/expr.test.ts
index e998605..3ed361f 100644
--- a/src/lib/expr.test.ts
+++ b/src/lib/expr.test.ts
@@ -11,6 +11,11 @@ describe("expr", () => {
["1 * 2", "2"],
["1 / 2", "0.5"],
["1 // 2", "0"],
+ ["1 % 2", "1"],
+ ["3 % 2", "1"],
+ ["-1 % 2", "1"],
+ // TODO: might change this! negative dividend is weird no matter what, but positive modulo is arguably the better call?
+ ["1 % -2", "-1"],
// TODO: operator precedence
// TODO: parentheses
])("%s", (expression, result) => {
diff --git a/src/lib/expr.ts b/src/lib/expr.ts
index 00dce77..9d6afb2 100644
--- a/src/lib/expr.ts
+++ b/src/lib/expr.ts
@@ -32,6 +32,7 @@ const MINUS_TOKEN = /\s*(\-)/y;
const TIMES_TOKEN = /\s*(\*)/y;
const FLOOR_TOKEN = /\s*(\/\/)/y;
const DIV_TOKEN = /\s*(\/)/y;
+const MOD_TOKEN = /\s*(\%)/y;
const NUMBER_TOKEN = /\s*(\d+)/y;
@@ -84,6 +85,7 @@ const Operators: TokenHandler[] = [
makeInfixOp(TIMES_TOKEN, 20, 21, (left, right) => ({ value: left * right })),
makeInfixOp(FLOOR_TOKEN, 20, 21, (left, right) => ({ value: Math.floor(left / right) })),
makeInfixOp(DIV_TOKEN, 20, 21, (left, right) => ({ value: left / right })),
+ makeInfixOp(MOD_TOKEN, 20, 21, (left, right) => ({ value: ((left % right) + right) % right })),
];
const ZERO = { value: 0 };
From 7e21e71a072ad78be0e72480bc531c9505f5d7e2 Mon Sep 17 00:00:00 2001
From: Tangent Wantwight <tangent128@gmail.com>
Date: Mon, 20 May 2024 20:39:12 -0400
Subject: [PATCH 10/12] Clarify division behavior in tests
---
src/lib/expr.test.ts | 24 ++++++++++++++++++------
src/lib/expr.ts | 27 +++++++++++++++++++--------
2 files changed, 37 insertions(+), 14 deletions(-)
diff --git a/src/lib/expr.test.ts b/src/lib/expr.test.ts
index 3ed361f..fbb0edb 100644
--- a/src/lib/expr.test.ts
+++ b/src/lib/expr.test.ts
@@ -10,12 +10,24 @@ describe("expr", () => {
["1 - 2", "-1"],
["1 * 2", "2"],
["1 / 2", "0.5"],
- ["1 // 2", "0"],
- ["1 % 2", "1"],
- ["3 % 2", "1"],
- ["-1 % 2", "1"],
- // TODO: might change this! negative dividend is weird no matter what, but positive modulo is arguably the better call?
- ["1 % -2", "-1"],
+ // floored division
+ ["1 // 5", "0"],
+ ["6 // 5", "1"],
+ ["-1 // 5", "-1"],
+ ["-6 // 5", "-2"],
+ ["1 // -5", "-1"],
+ ["6 // -5", "-2"],
+ ["-1 // -5", "0"],
+ ["-6 // -5", "1"],
+ // floored modulo
+ ["1 % 5", "1"],
+ ["6 % 5", "1"],
+ ["-6 % 5", "4"],
+ ["-1 % 5", "4"],
+ ["1 % -5", "-4"],
+ ["6 % -5", "-4"],
+ ["-6 % -5", "-1"],
+ ["-1 % -5", "-1"],
// TODO: operator precedence
// TODO: parentheses
])("%s", (expression, result) => {
diff --git a/src/lib/expr.ts b/src/lib/expr.ts
index 9d6afb2..81df33e 100644
--- a/src/lib/expr.ts
+++ b/src/lib/expr.ts
@@ -12,8 +12,8 @@ export function Expr({}, argv: TextPiece[]): ProcResult {
const parser = new ExpressionParser(expression);
const result = parser.parseSubExpression(0);
- if(parser.pos != expression.length) {
- return {error: "Couldn't parse full expression"}
+ if (parser.pos != expression.length) {
+ return { error: "Couldn't parse full expression" };
}
if ("value" in result) {
@@ -59,13 +59,20 @@ function map(
}
}
-function makeInfixOp(token:RegExp, leftBindingPower: number,rightBindingPower: number, op: (left: number, right: number) => Value | ErrorResult):TokenHandler {
+function makeInfixOp(
+ token: RegExp,
+ leftBindingPower: number,
+ rightBindingPower: number,
+ op: (left: number, right: number) => Value | ErrorResult
+): TokenHandler {
return {
leftBindingPower,
token,
parse: ({ value: left }, matched, parser) =>
- map(parser.parseSubExpression(rightBindingPower), (right) => op(left, right)),
- }
+ map(parser.parseSubExpression(rightBindingPower), (right) =>
+ op(left, right)
+ ),
+ };
}
const Operators: TokenHandler[] = [
@@ -78,14 +85,18 @@ const Operators: TokenHandler[] = [
leftBindingPower: -1,
token: MINUS_TOKEN,
parse: (left, matched, parser) =>
- map(parser.parseSubExpression(99), (right) => ({value: -right})),
+ map(parser.parseSubExpression(99), (right) => ({ value: -right })),
},
makeInfixOp(PLUS_TOKEN, 10, 11, (left, right) => ({ value: left + right })),
makeInfixOp(MINUS_TOKEN, 10, 11, (left, right) => ({ value: left - right })),
makeInfixOp(TIMES_TOKEN, 20, 21, (left, right) => ({ value: left * right })),
- makeInfixOp(FLOOR_TOKEN, 20, 21, (left, right) => ({ value: Math.floor(left / right) })),
+ makeInfixOp(FLOOR_TOKEN, 20, 21, (left, right) => ({
+ value: Math.floor(left / right),
+ })),
makeInfixOp(DIV_TOKEN, 20, 21, (left, right) => ({ value: left / right })),
- makeInfixOp(MOD_TOKEN, 20, 21, (left, right) => ({ value: ((left % right) + right) % right })),
+ makeInfixOp(MOD_TOKEN, 20, 21, (left, right) => ({
+ value: ((left % right) + right) % right,
+ })),
];
const ZERO = { value: 0 };
From 9acba7431ffaf53ee303a7a7334ba0d7b4ef5087 Mon Sep 17 00:00:00 2001
From: Tangent Wantwight <tangent128@gmail.com>
Date: Mon, 20 May 2024 20:53:06 -0400
Subject: [PATCH 11/12] More expr test cases
---
src/lib/expr.test.ts | 47 ++++++++++++++++++++++++++++++++++++--------
1 file changed, 39 insertions(+), 8 deletions(-)
diff --git a/src/lib/expr.test.ts b/src/lib/expr.test.ts
index fbb0edb..9095d40 100644
--- a/src/lib/expr.test.ts
+++ b/src/lib/expr.test.ts
@@ -2,7 +2,7 @@ import { AsText, TextPiece } from "../words";
import { Expr } from "./expr";
describe("expr", () => {
- describe("Expr does math", () => {
+ describe("does math", () => {
test.each([
["1", "1"],
["-1", "-1"],
@@ -28,8 +28,6 @@ describe("expr", () => {
["6 % -5", "-4"],
["-6 % -5", "-1"],
["-1 % -5", "-1"],
- // TODO: operator precedence
- // TODO: parentheses
])("%s", (expression, result) => {
const actualResult = Expr({}, [{ text: expression }]);
expect("error" in actualResult).toBeFalsy();
@@ -37,13 +35,46 @@ describe("expr", () => {
});
});
- // TODO; error reporting
- describe("Expr rejects invalid expressions", () => {
- test.each([["1 $ 2"], ["1 1 + 2"], ["$ 1"]])("%s", (expression) => {
+ describe("handles operator precedence", () => {
+ test.each([
+ ["1 - 2 + 1", "0"],
+ ["1 + 2 * 3", "7"],
+ ["1 / 2 + 3", "3.5"],
+ ])("%s", (expression, result) => {
const actualResult = Expr({}, [{ text: expression }]);
- expect("error" in actualResult).toBeTruthy();
+ expect("error" in actualResult).toBeFalsy();
+ expect(AsText(actualResult as TextPiece)).toEqual(result);
});
});
- // TODO: handle expr prefix
+ // TODO: parentheses
+
+ // TODO; error reporting
+ describe("rejects invalid expressions", () => {
+ test.each([[""], ["1 $ 2"], ["1 1 + 2"], ["1 + + 2"], ["$ 1"]])(
+ "%s",
+ (expression) => {
+ const actualResult = Expr({}, [{ text: expression }]);
+ expect("error" in actualResult).toBeTruthy();
+ }
+ );
+ });
+
+ // TODO: operators should only be accepted as bare words
+
+ describe("ignores an expr prefix", () => {
+ test.each([
+ [["1", "+", "2"]],
+ [["expr", "1", "+", "2"]],
+ [["1 + 2"]],
+ [["expr", "1 + 2"]],
+ ])("%s", (argv) => {
+ const actualResult = Expr(
+ {},
+ argv.map((text) => ({ bare: text }))
+ );
+ expect("error" in actualResult).toBeFalsy();
+ expect(AsText(actualResult as TextPiece)).toEqual("3");
+ });
+ });
});
From 7c74c9e34f18a365eb87e1a99a5b63c9d31bd2f4 Mon Sep 17 00:00:00 2001
From: Tangent Wantwight <tangent128@gmail.com>
Date: Wed, 5 Jun 2024 00:32:04 -0400
Subject: [PATCH 12/12] Add optional (and unused) offset parameter to parse()
signature
---
src/parser.ts | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/src/parser.ts b/src/parser.ts
index d9dc4d4..3f7ad78 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -137,10 +137,11 @@ const ERROR_CONTEXT = /(?<=([^\n]{0,50}))([^\n]{0,50})/y;
* Parse out a Notcl script into an easier-to-interpret representation.
* No script is actually executed yet.
*
- * @param - code to parse
- * @returns - parsed list of commands, or error message on failure
+ * @param code code to parse
+ * @param offset source position of code, if embedded in a larger source document
+ * @returns parsed list of commands, or error message on failure
*/
-export function parse(code: string): [true, Script] | [false, string] {
+export function parse(code: string, offset = 0): [true, Script] | [false, string] {
/* Parse */
const [commands, errorPos, expected] = Script.match(code, 0);