diff --git a/CHANGELOG.md b/CHANGELOG.md
index d7e0fc5a882844b87f6c2d901c67db930330c2de..2fa39f0ddc98faec5f8b39d077e8964b079331df 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
* Added support for Java 17.
* Updated ProB 2 to version 4.0.0-SNAPSHOT.
* Added a `:language` command to allow changing the language used to parse user input. For example `:language event_b` can be used to switch to Event-B syntax when a non-Event-B machine is loaded (or no machine at all).
+* Made `:let` syntax more flexible: both `:let name value` and `:let name=value` are now allowed.
* Improved the performance of loading machines by reusing the existing instance of ProB instead of starting a new one for each machine.
* Improved error highlighting for machines loaded from files and not from the notebook.
* Local variables (created using `:let`) are now discarded when a new machine is loaded. Previously local variables would be remembered even across machine loads, which could lead to confusing behavior and errors.
diff --git a/notebooks/tests/let.ipynb b/notebooks/tests/let.ipynb
index 1b4533e23df7297ad17be6f0fa602d7c285ee896..42303a03033289e6aad77e38666201985bf9731f 100644
--- a/notebooks/tests/let.ipynb
+++ b/notebooks/tests/let.ipynb
@@ -10,6 +10,7 @@
"text/markdown": [
"```\n",
":let NAME EXPR\n",
+ ":let NAME=EXPR\n",
"```\n",
"\n",
"Evaluate an expression and store it in a local variable.\n",
@@ -22,6 +23,7 @@
],
"text/plain": [
":let NAME EXPR\n",
+ ":let NAME=EXPR\n",
"Evaluate an expression and store it in a local variable.\n",
"\n",
"The expression is evaluated once in the current state, and its value is stored. Once set, variables are available in all states. A variable created by `:let` shadows any identifier with the same name from the machine.\n",
@@ -199,10 +201,10 @@
"outputs": [
{
"ename": "CommandExecutionException",
- "evalue": ":eval: Computation not completed: Unknown identifier \"n\", the possible completion is \"not\"",
+ "evalue": ":eval: Computation not completed: Unknown identifier \"n\", did you mean \"IN\"?",
"output_type": "error",
"traceback": [
- "\u001b[1m\u001b[31m:eval: Computation not completed: Unknown identifier \"n\", the possible completion is \"not\"\u001b[0m"
+ "\u001b[1m\u001b[31m:eval: Computation not completed: Unknown identifier \"n\", did you mean \"IN\"?\u001b[0m"
]
}
],
@@ -360,7 +362,7 @@
"cell_type": "markdown",
"metadata": {},
"source": [
- "Local variables can be used in Event-B mode."
+ "Local variables can be assigned with or without `=`."
]
},
{
@@ -370,8 +372,11 @@
"outputs": [
{
"data": {
+ "text/markdown": [
+ "$1$"
+ ],
"text/plain": [
- "Changed language for user input to Event-B (forced)"
+ "1"
]
},
"execution_count": 16,
@@ -380,13 +385,167 @@
}
],
"source": [
- ":language event_b"
+ ":let x 1"
]
},
{
"cell_type": "code",
"execution_count": 17,
"metadata": {},
+ "outputs": [
+ {
+ "data": {
+ "text/markdown": [
+ "$2$"
+ ],
+ "text/plain": [
+ "2"
+ ]
+ },
+ "execution_count": 17,
+ "metadata": {},
+ "output_type": "execute_result"
+ }
+ ],
+ "source": [
+ ":let y=2"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 18,
+ "metadata": {},
+ "outputs": [
+ {
+ "data": {
+ "text/markdown": [
+ "$\\mathit{TRUE}$"
+ ],
+ "text/plain": [
+ "TRUE"
+ ]
+ },
+ "execution_count": 18,
+ "metadata": {},
+ "output_type": "execute_result"
+ }
+ ],
+ "source": [
+ ":assert x + 1 = y"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 19,
+ "metadata": {},
+ "outputs": [
+ {
+ "data": {
+ "text/markdown": [
+ "$\\{0,2,4,6,8,10\\}$"
+ ],
+ "text/plain": [
+ "{0,2,4,6,8,10}"
+ ]
+ },
+ "execution_count": 19,
+ "metadata": {},
+ "output_type": "execute_result"
+ }
+ ],
+ "source": [
+ ":let X {x | x : 0..10 & x mod 2 = 0}"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 20,
+ "metadata": {},
+ "outputs": [
+ {
+ "data": {
+ "text/markdown": [
+ "$\\{0,2,4,6,8,10\\}$"
+ ],
+ "text/plain": [
+ "{0,2,4,6,8,10}"
+ ]
+ },
+ "execution_count": 20,
+ "metadata": {},
+ "output_type": "execute_result"
+ }
+ ],
+ "source": [
+ ":let Y={x | x : 0..10 & x mod 2 = 0}"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 21,
+ "metadata": {},
+ "outputs": [
+ {
+ "data": {
+ "text/markdown": [
+ "$\\mathit{TRUE}$\n",
+ "\n",
+ "**Solution:**\n",
+ "* $\\mathit{x} = 1$\n",
+ "* $\\mathit{X} = \\{0,2,4,6,8,10\\}$\n",
+ "* $\\mathit{y} = 2$\n",
+ "* $\\mathit{Y} = \\{0,2,4,6,8,10\\}$"
+ ],
+ "text/plain": [
+ "TRUE\n",
+ "\n",
+ "Solution:\n",
+ "\tx = 1\n",
+ "\tX = {0,2,4,6,8,10}\n",
+ "\ty = 2\n",
+ "\tY = {0,2,4,6,8,10}"
+ ]
+ },
+ "execution_count": 21,
+ "metadata": {},
+ "output_type": "execute_result"
+ }
+ ],
+ "source": [
+ "X = Y"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "Local variables can be used in Event-B mode."
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 22,
+ "metadata": {},
+ "outputs": [
+ {
+ "data": {
+ "text/plain": [
+ "Changed language for user input to Event-B (forced)"
+ ]
+ },
+ "execution_count": 22,
+ "metadata": {},
+ "output_type": "execute_result"
+ }
+ ],
+ "source": [
+ ":language event_b"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 23,
+ "metadata": {},
"outputs": [
{
"data": {
@@ -397,7 +556,7 @@
"{1,2,3,4,5,10}"
]
},
- "execution_count": 17,
+ "execution_count": 23,
"metadata": {},
"output_type": "execute_result"
}
@@ -408,7 +567,7 @@
},
{
"cell_type": "code",
- "execution_count": 18,
+ "execution_count": 24,
"metadata": {},
"outputs": [
{
@@ -420,7 +579,7 @@
"{1,2,3,4,5,10}"
]
},
- "execution_count": 18,
+ "execution_count": 24,
"metadata": {},
"output_type": "execute_result"
}
@@ -431,7 +590,7 @@
},
{
"cell_type": "code",
- "execution_count": 19,
+ "execution_count": 25,
"metadata": {},
"outputs": [
{
@@ -443,7 +602,7 @@
"{1,2,3,4,5,10}"
]
},
- "execution_count": 19,
+ "execution_count": 25,
"metadata": {},
"output_type": "execute_result"
}
@@ -454,7 +613,7 @@
},
{
"cell_type": "code",
- "execution_count": 20,
+ "execution_count": 26,
"metadata": {},
"outputs": [
{
@@ -466,7 +625,7 @@
"FALSE"
]
},
- "execution_count": 20,
+ "execution_count": 26,
"metadata": {},
"output_type": "execute_result"
}
@@ -477,7 +636,7 @@
},
{
"cell_type": "code",
- "execution_count": 21,
+ "execution_count": 27,
"metadata": {},
"outputs": [
{
@@ -489,7 +648,7 @@
"TRUE"
]
},
- "execution_count": 21,
+ "execution_count": 27,
"metadata": {},
"output_type": "execute_result"
}
@@ -500,7 +659,7 @@
},
{
"cell_type": "code",
- "execution_count": 22,
+ "execution_count": 28,
"metadata": {},
"outputs": [
{
@@ -518,7 +677,7 @@
"\tA = {0,1}"
]
},
- "execution_count": 22,
+ "execution_count": 28,
"metadata": {},
"output_type": "execute_result"
}
diff --git a/src/main/java/de/prob2/jupyter/commands/LetCommand.java b/src/main/java/de/prob2/jupyter/commands/LetCommand.java
index 1ee993dcfb85d4701575bf4e25e3b0f750049918..e591444456dbc714b17c929ec9d870b255ea0138 100644
--- a/src/main/java/de/prob2/jupyter/commands/LetCommand.java
+++ b/src/main/java/de/prob2/jupyter/commands/LetCommand.java
@@ -1,6 +1,7 @@
package de.prob2.jupyter.commands;
-import java.util.Arrays;
+import java.util.Collections;
+import java.util.regex.Pattern;
import com.google.inject.Inject;
import com.google.inject.Provider;
@@ -18,14 +19,16 @@ import de.prob2.jupyter.ParameterInspectors;
import de.prob2.jupyter.Parameters;
import de.prob2.jupyter.ParsedArguments;
import de.prob2.jupyter.ProBKernel;
+import de.prob2.jupyter.UserErrorException;
import io.github.spencerpark.jupyter.kernel.display.DisplayData;
import org.jetbrains.annotations.NotNull;
public final class LetCommand implements Command {
- private static final @NotNull Parameter.RequiredSingle NAME_PARAM = Parameter.required("name");
- private static final @NotNull Parameter.RequiredSingle EXPRESSION_PARAM = Parameter.requiredRemainder("expression");
+ private static final @NotNull Parameter.RequiredSingle NAME_AND_EXPRESSION = Parameter.requiredRemainder("nameAndExpression");
+
+ private static final @NotNull Pattern NAME_AND_EXPRESSION_SPLIT_PATTERN = Pattern.compile("=|\\s+");
private final @NotNull Provider<@NotNull ProBKernel> kernelProvider;
private final @NotNull AnimationSelector animationSelector;
@@ -45,12 +48,12 @@ public final class LetCommand implements Command {
@Override
public @NotNull Parameters getParameters() {
- return new Parameters(Arrays.asList(NAME_PARAM, EXPRESSION_PARAM));
+ return new Parameters(Collections.singletonList(NAME_AND_EXPRESSION));
}
@Override
public @NotNull String getSyntax() {
- return ":let NAME EXPR";
+ return ":let NAME EXPR\n:let NAME=EXPR";
}
@Override
@@ -67,9 +70,15 @@ public final class LetCommand implements Command {
@Override
public @NotNull DisplayData run(final @NotNull ParsedArguments args) {
- final String name = args.get(NAME_PARAM);
+ final String[] split = NAME_AND_EXPRESSION_SPLIT_PATTERN.split(args.get(NAME_AND_EXPRESSION), 2);
+ if (split.length != 2) {
+ throw new UserErrorException("Missing variable value");
+ }
+ final String name = split[0];
+ final String expression = split[1];
+
final ProBKernel kernel = this.kernelProvider.get();
- final IEvalElement formula = kernel.parseFormula(args.get(EXPRESSION_PARAM), FormulaExpand.EXPAND);
+ final IEvalElement formula = kernel.parseFormula(expression, FormulaExpand.EXPAND);
final AbstractEvalResult evaluated = CommandUtils.withSourceCode(formula, () ->
kernel.postprocessEvalResult(this.animationSelector.getCurrentTrace().evalCurrent(formula))
);